The role of planktonic Flavobacteria in processing algal organicFor matter Peer in coastal Review East Antarctica Only revealed using metagenomics and metaproteomics
Journal: Environmental Microbiology and Environmental Microbiology Reports
Manuscript ID: EMI-2012-0714.R1
Manuscript Type: EMI - Research article
Journal: Environmental Microbiology
Date Submitted by the Author: n/a
Complete List of Authors: Cavicchioli, Ricardo
ecophysiology, environmental genomics, functional diversity, Keywords: genomics/functional genomics/comparative genomics, bacteria, metagenomics/community genomics, microbial ecology, archaea
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The role of planktonic Flavobacteria in processing algal
organic matter in coastal East Antarctica revealed using
metagenomics and metaproteomics For Peer Review Only Timothy J. Williams 1, David Wilkins 1, Emilie Long 1,2 , Flavia Evans 1, Mathew Z.
DeMaere 1, Mark J. Raftery 3, and Ricardo Cavicchioli 1†
1 School of Biotechnology and Biomolecular Sciences, The University of New South
Wales, Sydney, New South Wales, 2052, Australia.
2 UFR 927, Université Pierre et Marie Curie (UPMC) Paris VI, 4 place Jussieu 75532,
Paris, France
3 Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney,
New South Wales, 2052, Australia.
† To whom correspondence should be addressed. E mail: [email protected]
Running head: Metaproteomics of marine Antarctic Flavobacteria
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1 Summary
2
3 Heterotrophic marine bacteria play key roles in remineralizing organic matter
4 generated from primary production. However, far more is known about which 5 groups areFor dominant Peerthan about the Review cellular processes they Only perform in order to 6 become dominant. In the Southern Ocean, eukaryotic phytoplankton are the
7 dominant primary producers. In this study we used metagenomics and
8 metaproteomics to determine how the dominant bacterial and archaeal plankton
9 processed bloom material. We examined the microbial community composition in
10 fourteen metagenomes and found that the relative abundance of Flavobacteria
11 (dominated by Polaribacter ) was positively correlated with chlorophyll a
12 fluorescence, and the relative abundance of SAR11 was inversely correlated with
13 both fluorescence and Flavobacteria abundance. By performing metaproteomics on
14 the sample with the highest relative abundance of Flavobacteria (Newcomb Bay,
15 East Antarctica) we defined how Flavobacteria attach to and degrade diverse
16 complex organic material, how they make labile compounds available to
17 Alphaproteobacteria (especially SAR11) and Gammaproteobacteria , and how these
18 heterotrophic Proteobacteria target and utilize these nutrients. The presence of
19 methylotrophic proteins for archaea and bacteria also indicated the importance of
20 metabolic specialists. Overall, the study provides functional data for the microbial
21 mechanisms of nutrient cycling at the surface of the coastal Southern Ocean.
22
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23 Introduction
24
25 Bacterioplankton populations in the world’s oceans are typically dominated by three
26 bacterial clades: Alphaproteobacteria , Gammaproteobacteria , and Bacteroidetes 27 (Glöckner Foret al. , 1999; Peer Kirchman, 2002; Review Kirchman et al. , 2003; Only O’Sullivan et al. , 2004; 28 Abell and Bowman, 2005a). They also dominate Southern Ocean bacterioplankton
29 populations in the austral summer (Abell and Bowman, 2005a,b; Murray and Grzymski,
30 2007; Jamieson et al. , 2012; Grzymski et al., 2012).
31 Flavobacteria , the major clade of Bacteroidetes in the marine environment, are
32 heterotrophs that target complex organic matter, and specialize in the degradation of
33 biopolymers (Pinhassi et al. , 1999; Cottrell and Kirchman. 2000; Kirchman, 2002; Abell
34 and Bowman, 2005a,b; González et al. , 2008; Teeling et al. , 2012). Flavobacteria target
35 high molecular weight compounds and tend to be abundant during phytoplankton blooms
36 (DeLong et al., 1993; Glöckner et al. , 1999; Pinhassi, 2004; West et al. , 2008; Teeling et
37 al. , 2012). Increased Flavobacteria abundance has been linked to enhanced primary
38 production (Brown and Bowman, 2001; Kirchman, 2002; Horner Devine et al. , 2003;
39 Abell and Bowman, 2005a; Murray and Grzymski, 2007), consistent with their role as
40 major mineralizers of organic matter (Cottrell and Kirchman, 2000). Flavobacteria are
41 especially important as the “first responders” to phytoplankton blooms, and by breaking
42 down complex organic matter by direct attachment and exoenzymatic attack of algal cells
43 and algal derived detrital particles (Kirchman, 2002; Gómez Pereira et al. , 2012; Teeling
44 et al. , 2012). Consistent with this, Flavobacteria tend to be abundant in the Southern
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45 Ocean where the waters are enriched in nutrients and phytoplankton (Abell and Bowman
46 2005a), particularly in summer (Grzymski et al., 2012; Williams et al., 2012).
47 Marine Alphaproteobacteria populations are dominated by the SAR11 and
48 Roseobacter clades, which favor labile substrates, including byproducts from the growth 49 of algae andFor Flavobacteria Peer (Mou et al.Review, 2008; Teeling et al. , 2012).Only Members of the 50 SAR11 clade are obligately planktonic, scavenge low concentrations of nutrients from
51 seawater (Morris et al. , 2002; Giovannoni et al. , 2005), and are most abundant where
52 phytoplankton biomass and primary production are low (Morris et al. , 2002; Sowell et
53 al. , 2009). Members of the Roseobacter clade of the Rhodobacterales are metabolically
54 diverse, targeting a wider range of substrates than SAR11 (Wagner Döbler and Biebl,
55 2006; Moran et al. , 2007), and are often found in close association with phytoplankton
56 (Pinhassi et al. , 2004; West et al. , 2008). SAR116 is a clade of Alphaproteobacteria that
57 has also been detected in a range of marine environments, and has been regarded as a
58 metabolic generalist (Oh et al. , 2010). Gammaproteobacteria also comprise a major
59 component of marine bacterioplankton, and are represented by phylogenetically diverse
60 clades. Marine members of Oceanospirillales and Alteromonadales include heterotrophs
61 with broad substrate preferences, with cold adapted genera such as Colwellia ,
62 Pseudoalteromonas , Marinobacter and Psychromonas recorded in Southern Ocean
63 seawater and sea ice off Antarctica (Bowman et al. , 1997; Piquet et al. , 2011). The
64 Oligotrophic Marine Gammaproteobacteria (OMG) group are physiologically diverse
65 marine heterotrophs that have been shown to be obligately oligotrophic when grown in
66 culture (Cho and Giovannoni, 2004).
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67 In addition to these groups, Antarctic surface waters include putative
68 chemolithoautotrophs, notably sulfur oxidizing Gammaproteobacteria and ammonia
69 oxidizing Marine Group I Crenarchaeota (MGI), as major components of the
70 picoplankton (Murray and Grzymski, 2007; Gzymski et al. , 2012; Williams et al. , 2012). 71 Bacteria ofFor the gammaproteobacterial Peer Reviewsulfur oxidizer EOSA 1 Only (GSO EOSA 1) complex 72 have been reported in global mesopelagic waters (Swan et al., 2011) and oxygen
73 minimum zones (Walsh et al., 2009; Canfield et al., 2010), and their ecological role in
74 surface waters is yet to be determined (Grzymski et al. , 2012; Williams et al. , 2012).
75 MGI (also called Thaumarchaeota ) appear to play an important role performing ‘dark’
76 chemolithotrophic carbon fixation and nitrification in the bulk ocean (Konneke et al. ,
77 2005; Wuchter et al., 2006; Berg et al. , 2007), as well as in Antarctic surface waters in
78 winter (Grzymski et al. , 2012; Williams et al. , 2012).
79 In the North Sea, specific populations of Alphaproteobacteria ,
80 Gammaproteobacteria and Bacteroidetes have been shown to successively exploit
81 organic matter in response to diatom blooms (Teeling et al. , 2012). During the decline in
82 chlorophyll a levels that followed a bloom (marked by a rapid increase in chlorophyll a
83 levels from essentially zero to ~25 g L 1), the relative abundances of specific
84 Flavobacteria (Ulvibacter spp., Formosa spp., and Polaribacter spp.) and
85 Gammaproteobacteria (Reinekea spp. and SAR92 clade) were found to peak, while
86 specific groups of Alphaproteobacteria (SAR11 and Roseobacter clade) remained
87 comparatively constant (Teeling et al. , 2012).
88 The Southern Ocean is dominated by eukaryotic phytoplankton (rather than
89 Cyanobacteria ), and consists mainly of diatoms, dinoflagellates, and haptophytes (Wright
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90 et al. , 2010). Antarctic surface blooms occur as a result of release of nutrients
91 (particularly iron) upwelled over winter or through other nutrient incursions (Boyd and
92 Ellwood, 2010). For much of the Southern Ocean, surface concentrations of <0.3 – 0.4 g
93 L 1 are typical, while higher chlorophyll concentrations (>1 g L 1) are associated with 94 the major SouthernFor Ocean Peer fronts, ice edgeReview blooms during sea ice Only retreat in summer, and 95 coastal/shelf waters (Moore and Abbott, 2000). However to date, metagenome or
96 metaproteome based studies of the bacterial and archaeal communities associated with
97 high chlorophyll a blooms in the Southern Ocean have not been reported.
98 In the current study we analyzed metagenomic data from 14 surface locations in the
99 Southern Ocean of East Antarctica, including coastal sites, to examine the comparative
100 diversity of community composition, and determine the abundance of Flavobacteria
101 relative to community composition and chlorophyll a levels. We then targeted for
102 metaproteomic analysis a sample from Newcomb Bay that was highly enriched in
103 Flavobacteria , in order to elucidate the processes by which these heterotrophs procured
104 and processed substrates, and contributed toward remineralization of organic matter. In
105 association with metaproteomic data for Alphaproteobacteria and Gammaproteobacteria
106 we gained insights into how coastal Antarctic bacterioplankton target substrates,
107 particularly those that could be linked to algal turnover, and what the major microbial
108 pathways were that were operating at the ocean surface.
109
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110 Results and discussion
111
112 Phylogenetic diversity and influence of environmental factors on the community
113 composition of 14 Southern Ocean metagenomes 114 For Peer Review Only 115 To evaluate the representation of major taxonomic groups in the 14 Southern Ocean
116 metagenomes, the operational taxonomic unit (OTUs) from Genome Abundance and
117 Average Size (GAAS) analysis were manually sorted into Flavobacteria , SAR11,
118 Rhodobacterales , GSO EOSA 1 complex, OMG, Oceanospirillales +Alteromonadales ,
119 SAR116, and MGI (Table 1, Fig. 1). OTUs pertaining to Oceanospirillales or
120 Alteromonadales were combined into one group due to the difficulty of resolving
121 relationships between members of these two Gammaproteobacteria orders (Williams et
122 al. , 2010). All the OTUs for phylum Bacteroidetes were members of the class
123 Flavobacteria .
124 OTUs with best matches to Bacteroidetes made up 3.2 to 50.4% of the metagenome
125 across the 14 samples (Table 1). The relative abundance of Flavobacteria was strongly
126 positively correlated with chlorophyll a fluorescence (Pearson's correlation coefficient r =
127 +0.81, p < 0.01) (Fig. 2). The wide range of chlorophyll a concentrations (0.14 to 12.1 g
128 L 1) examined represent numerous stages of Southern Ocean algal blooms (Fig. 1 and 2).
129 By comparison, using DGGE 16S rRNA gene sequencing and fluorescent in situ
130 hybridization, no correlation was previously found between chlorophyll a fluorescence
131 and the abundance of planktonic Flavobacteria (size range 0.2 – 0.8 m) (Abell and
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132 Bowman, 2005a). However, notably in this study the chlorophyll a fluorescence in the
133 Southern Ocean samples only ranged from ~ 0.30 to 0.55 g L 1.
134 Our metagenome samples also resolved specific Flavobacteria OTUs, with
135 Polaribacter spp. and Psychroflexus torquis exhibiting significant correlations with 136 fluorescenceFor ( r = +0.82, Peer p < 0.01 and Reviewr = +0.69, p < 0.01, respectively). Only For all 14 137 samples, GAAS analysis showed Polaribacter spp. to be the dominant constituent of total
138 Bacteroidetes (67.8 – 97.6%). Other OTUs for Bacteroidetes that comprised at least
139 0.02% of metagenome data in at least one of the 14 samples included those with best
140 matches to Ps. torquis, Zunongwangia profunda, Flavobacterium spp ., Gramella forsetii
141 and the insect endosymbiont Ca. “Sulcia muelleri”. This is consistent with the significant
142 phylogenetic diversity for Bacteroidetes observed previously for Southern Ocean
143 Flavobacteria (Abell and Bowman, 2005a).
144 Members of the SAR11 clade (class Alphaproteobacteria ) were highly abundant
145 with OTUs ranging from 36.9 to 50.4% across the 14 samples (Table 1). The OTUs
146 represented Ca. “Pelagibacter ubique” HTCC1062, Ca. “P. ubique” HTCC1002, and Ca .
147 “Pelagibacter” sp. HTCC7211. The relative abundance of SAR11 was weakly inversely
148 correlated with fluorescence ( r = 0.56, p < 0.05), but strongly inversely correlated with
149 the relative abundance of Flavobacteria (r = 0.80, p < 0.01) (Fig. 2). A negative
150 correlation between SAR11 and phytoplankton blooms was previously observed in
151 Antarctic Peninsula and Kerguelen Island waters (Ghiglioni and Murray, 2012).
152 OTUs with the best matches to order Rhodobacterales (class Alphaproteobacteria )
153 comprised 0.4 to 7.7% of relative abundances in the metagenome (Table 1), including
154 OTUs with best matches to Roseobacter denitrificans, Ruegeria sp. TM1040, and the
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155 proteorhodopsin containing Roseobacter clade strain HTCC2255. However, no
156 relationship was found between Rhodobacterales and fluorescence, despite a reported
157 association of certain members of the Roseobacter clade with phytoplankton (Buchan et
158 al. , 2005; Moran et al. , 2007). 159 The SAR116For clade Peer (class Alphaproteobacteria Review) was represented Only by a single OTU 160 with the best match to Ca. “Puniceispirillum marinum” IMCC1322 (Oh et al. , 2010),
161 which made up < 0.2% of the metagenome data (Table 1). Relative abundances of
162 SAR116 and Oceanospirillales +Alteromonadales (class Gammaproteobacteria ) were
163 strongly correlated ( r = +0.86, p < 0.01). This was unrelated to fluorescence, water
164 column depth, or distance from the coastline. The Oceanospirillales +Alteromonadales
165 group was represented in the metagenome by OTUs with best matches to the genera
166 Colwellia, Marinobacter, Marinomonas, Neptuniibacter, Pseudoalteromonas,
167 Psychromonas, Saccharophagus, and Shewanella . When combined, the
168 Oceanospirillales +Alteromonadales group made up 0.08 to 2.2% of the total
169 metagenome data (Table 1). A strong correlation was also observed between the relative
170 abundances of OMG (represented by uncultivated strain NOR5 3) and
171 Alteromonadales +Oceanospirillales (r = +0.89, p < 0.01), and between OMG and
172 SAR116 ( r = +0.92, p < 0.01).
173 The detection of GSO EOSA 1 (order Thiotrichales , class Gammaproteobacteria;
174 Williams et al. , 2010) is indicative of the presence of free living pelagic members of this
175 complex, including the gammaproteobacterial SUP05/Arctic96BD 19 clade (Walsh et al. ,
176 2009; Swan et al. , 2011). The GSO EOSA 1 OTUs had best matches to Ca. “Ruthia
177 magnifica” and Ca. “Vesicomyosocius okutanii”, endosymbionts of deep sea bivalves
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178 (Newton et al. , 2007; Kuwahara et al. , 2011), and comprised up to 7.9% of the
179 metagenome across the 14 samples (Table 1). It is likely these OTUs attracted sequences
180 originating from planktonic GSO EOSA 1 bacteria. Ca. “R. magnifica” and Ca. “V.
181 okutanii” are chemolithoautotrophs (Newton et al. , 2007; Kuwahara et al. , 2011), 182 although a Forrecently isolated Peer member ofReview the SUP05/Arctic96BD 19 Only clade from the North 183 Pacific gyre was inferred to be an aerobic, sulfur oxidizing heterotroph (Marshall and
184 Morris, 2012). Other members of Thiotrichales also found matches in the NB
185 metagenome (e.g., Thiomicrospira crunogena ). Our study found no correlation between
186 relative abundance of GSO EOSA 1 OTUs and water column depth, meaning that their
187 presence in surface waters is unlikely to be due solely to deep mixing.
188 MGI had the closest genomic match to the ammonia oxidizing species Ca.
189 “Nitrosopumilus maritimus” (Table 1). MGI showed the greatest range of contributions
190 across the 14 metagenomic samples, with OTUs with best matches to Ca. “N. maritimus”
191 making up to 10.2% of the total metagenome (Table 1). After logarithmic transformation,
192 the relative abundance of MGI was found to be inversely correlated with both the depth
193 of the water column and the distance from the Antarctic landmass ( r = 0.80, p < 0.01 and
194 r = 0.78, p < 0.01, respectively).
195
196
197 Newcomb Bay metaproteogenomic overview
198
199 The Newcomb Bay metagenome (NB metagenome) and Newcomb Bay metaproteome
200 (NB metaproteome) were defined by matches to Bacteria, Archaea and viruses (see
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201 Experimental procedures) enabling the data to be directly compared. The Newcomb Bay
202 sample (#235; Fig. 1) was chosen because it contained the highest proportion of
203 Flavobacteria (Table 1, Fig. 2 and 3). A total of 548 proteins were identified (Table S1),
204 of which 446 proteins were identified using the AntComb database, 102 using NR, and 5 205 were commonFor to both. Peer A list of all proteins Review detected in the NB Only metaproteome that are 206 discussed in the main text is provided in Table 2. Of the 102 proteins identified using NR,
207 43 matched eukaryotic taxa, with 21 of these matching proteins of the diatom genus
208 Thalassiosira . Overall, protein sequence data was far better represented in fosmids and
209 shotgun metagenomic data than in microbial genomes contained in NR. Nevertheless, it
210 was only through NR that proteins pertaining to methanogenic Euryarchaeota were
211 detected (see Methylotrophy below); this clade was not detected in the metagenome.
212 Counts of unique peptides and assigned spectra are shown in Table S2.
213 A total of 472 proteins had highest sequence identity to bacterial proteins, 12 to
214 archaeal proteins, 61 to eukaryotic proteins, and three to virus (phage) proteins. Within
215 the bacterial subset, the majority had the best match (highest sequence identity) to
216 proteins from members of the Bacteroidetes (221), Gammaproteobacteria (174), and
217 Alphaproteobacteria (69). Protein matches to the Bacteroidetes clade were mainly to
218 Flavobacteria (216). Within the Gammaproteobacteria , most of the proteins had the best
219 match to Oceanospirillales +Alteromonadales (107), OMG (27), Pseudomonadales (17),
220 and GSO EOSA 1 (13). For the Alphaproteobacteria , nearly half (34) of the matches had
221 highest identity to proteins from the Rhodobacterales; other proteins had best matches to
222 members of the oligotrophic SAR11 cluster (including Ca. “Pelagibacter ubique”; 23),
223 Rhizobiales (6), and uncultivated SAR116 cluster (5). Proteins from Alphaproteobacteria
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224 were mostly from ATP binding cassette (ABC) transporters or other active transport
225 systems that involve solute binding (48) (see Uptake of labile solutes below).
226 Bacteroidetes and SAR11 comprised 50.5% and 36.9% of the NB metagenome, and
227 45.4 and 4.7% of the NB metaproteome, respectively (Table 1, Fig. 3). In the NB 228 metaproteome,For all but Peerfive of the 221 ReviewBacteroidetes proteins hadOnly best matches to 229 Flavobacteria , and 183 had best matches to Polaribacter spp. (Table S1), consistent with
230 their dominance in the metaproteome sampled from the decay phase of a North Sea algal
231 bloom (Teeling et al. , 2012). The much higher relative abundance of protein matches to
232 Flavobacteria compared to SAR11 likely reflects their particular trophic strategies.
233 Marine Flavobacteria are copiotrophs that specialize in the exploitation of organic matter
234 that results from algal blooms (Kirchman, 2002; Gómez Pereira et al. , 2012; Teeling et
235 al. , 2012), and therefore exhibit increased protein synthesis levels to maximize capture
236 and processing of available complex substrates. SAR11 are non motile oligotrophs that
237 are reliant on dilute concentrations of labile nutrients (Giovannoni et al ., 2005), and the
238 synthesis of cellular proteins by SAR11 is likely to be relatively unresponsive to
239 increases in nutrient load. Also, whereas diverse Flavobacteria target multiple polymeric
240 substrates that require extracytoplasmic processing prior to import, SAR11 expresses
241 extracytoplasmic proteins that target labile solutes (such as amino acids) which are
242 processed cytoplasmically (see Uptake of labile solutes , below). High expression levels
243 of these extracytoplasmic proteins are needed to enhance the frequency of substrate
244 binding and initial degradation ( Flavobacteria ) or solute capture (SAR11), whereas
245 subsequent conversion of the imported substrates requires a relatively lower level of
246 expression of cytoplasmic enzymes (Sowell et al ., 2009).
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247 Similar to SAR11, some other microbial groups exhibited large differences between
248 their representation in the NB metagenome and NB metaproteome (Fig. 3). For example,
249 Oceanospirillales +Alteromonadales represented 0.6% of the NB metagenome but 22.2%
250 of the NB metaproteome, and Rhodobacterales represented 0.23% and 7%, respectively. 251 Certain microorganismsFor Peer that comprise Review numerically minor components Only of a community 252 have been shown to be major contributors to nutrient cycling (Musat et al. , 2008). The
253 NB metaproteome includes proteins consistent with chemoorganotrophic growth in
254 Antarctic surface waters (see Biopolymer utilization and Uptake of labile solutes , below).
255 For Oceanospirillales +Alteromonadales , the detection of Krebs cycle and
256 gluconeogenesis enzymes (Table S1) could indicate that a higher proportion of carbon is
257 being diverted to storage rather than to growth. By contrast, the central metabolic
258 pathways evident for Flavobacteria indicate both biomass production and carbon storage
259 pathways are active (Table S1).
260 GSO EOSA 1 represented 1.7% of the NB metagenome and 2.7% of the NB
261 metaproteome, but the identities of the detected proteins offered few clues as to the
262 ecophysiology of this group at the surface, aside from expression of housekeeping genes
263 (Table S1). In an environment dominated by algal driven primary production and
264 exposed to around the clock solar illumination, the NB metaproteome shows no evidence
265 for light independent (‘dark’) carbon fixation at the surface by chemolithoautotrophic
266 bacteria or archaea.
267 MGI proteins were not detected in the NB metaproteome despite MGI having a
268 relative NB metagenome abundance of 4.4% (Table 1). In a study of Southern Ocean
269 surface waters near the Antarctic Peninsula, MGI proteins were not detected in the
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270 summer metaproteome, whereas MGI proteins were abundant in winter (Williams et al. ,
271 2012). The presence of MGI in surface waters in the NB metagenome (Table 1) may be
272 due to the upwelling of cells from bottom sediments of the relatively shallow waters of
273 Newcomb Bay. MGI have been detected at the surface of the Arctic Ocean, although no 274 seasonal patternFor was identifiedPeer (Galand Review et al ., 2009), and numbers Only were found to be 275 depressed by riverine input in coastal Arctic waters (Galand et al ., 2008). MGI were not
276 detected in the picoplankton metagenome from the Southern Ocean near the Antarctic
277 Peninsula (Grzymski et al ., 2012), although they were a dominant component in the
278 winter where they made up 12% of the metagenome and 30% of the metaproteome
279 (Grzymski et al ., 2012; Williams et al ., 2012). MGI have been detected in benthic
280 sediments along the Antarctic continental shelf (Bowman and McCuaig, 2003). The
281 current data are consistent with MGI being adventitiously brought to the surface of the
282 Southern Ocean from local sediment or deeper waters (and hence are less likely to reach
283 the surface in water columns of increasing depth), but have minimal metabolic activity at
284 the surface in the austral summer. This may be due to factors that suppress growth and
285 activity of MGI, such as extensive illumination (photoinhibition; Kalanetra et al., 2009;
286 Merbt et al. , 2011).
287 Protein matches to eukaryotic phytoplankton were predominantly from various
288 diatom species (45/61), principally Thalassiosira spp. (34; Table S1). Macroplankton
289 would be expected to be captured by the 20 m prefilter or 3 m filter (see Materials and
290 Methods ). The eukaryotic proteins present on the 0.1 m filters are therefore likely to
291 originate from phytoplankton turnover, or from unicellular microalgae such as
292 Ostreococcus tauri . The presence of diatom proteins is consistent with the association of
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293 Flavobacteria with diatoms (Pinhassi et al. , 2004; Fandino et al. , 2005; Grossart et al. ,
294 2005; Piquet et al. , 2011; Teeling et al. , 2012).
295
296 Ecophysiological processes performed by Flavobacteria and other members of the 297 Newcomb BayFor community Peer Review Only 298
299 Biopolymer utilization: Predicted outer membrane proteins were a major component of
300 the NB metaproteome, especially components of TonB dependent transporter (TBDT)
301 systems, with receptors representing 6.6% of the NB metaproteome and 1.8% of the NB
302 metagenome (the highest abundance of all identified genes in the dataset) (Table 3).
303 TBDTs are outer membrane transporters involved in the uptake of macromolecules that
304 are too large to diffuse via porins. TBDTs that target biopolymers (e.g., polysaccharides,
305 proteins, proteoglycan) act in concert with outer membrane substrate binding proteins
306 and degradative enzymes (e.g., glycosyl hydrolases, peptidases) to facilitate the use of
307 these complex substrates (Reeves et al. , 1997; Gilbert, 2008).The majority of TBDTs in
308 the NB metaproteome had the best matches to Flavobacteria , although some were to the
309 OMG (Tables 3 and S1); similar transporter expression profiles to these have been
310 described for the North Sea for Flavobacteria and OMG (Teeling et al. , 2012). Other
311 marine metaproteomic studies have reported TBDT components to represent 7% (before)
312 and 13% (during) a diatom associated bacterioplankton bloom in North Sea surface
313 waters (Teeling et al. , 2012), and to be very abundant in nutrient enriched coastal marine
314 systems (Morris et al. , 2010; Teeling et al. , 2012). TBDT proteins most closely related to
315 Bacteroidetes and Gammaproteobacteria were the dominant membrane protein class in
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316 coastal seawater of the South Atlantic Ocean (Morris et al. , 2010) and of the Southern
317 Ocean off the Antarctic Peninsula in the austral summer (Williams et al. , 2012).
318 Several secreted glycosyl hydrolases, including beta glucanases, were detected in the
319 NB metaproteome (Tables 3 and S1), which indicates that the Newcomb Bay population 320 of FlavobacteriaFor were Peertargeting storage Review polysaccharides from Only algae as substrates. Also 321 detected were predicted secreted and cytoplasmic aminopeptidases with best matches to
322 Flavobacteria (Tables 3 and S1). These findings are consistent with Polaribacter sp.
323 MED152 encoding large numbers of genes encoding peptidases, glycosyl hydrolases, and
324 TBDTs (González et al. , 2008), and Flavobacteria showing increased glycosyl hydrolase
325 and aminopeptidase activities associated with the utilization of carbohydrates and
326 proteins in seawater microcosm experiments (Pinhassi et al. , 2004). In addition to
327 targeting polysaccharides and proteins, predicted secreted enzymes with lipolytic or
328 phosphohydrolase domains (Table S1) were identified, indicating that a diversity of non
329 labile substrates were being utilized. Gliding motility proteins were detected (Tables 3
330 and S1), which allow exploration of solid surfaces by Flavobacteria (McBride, 2001).
331 Also detected were predicted secreted flavobacterial proteins with domains associated
332 with protein protein interactions (TPR, PKD) or cell adhesion (fasciclin) (Table S1);
333 these hypothetical proteins might play roles in the adhesion of Flavobacteria to algal
334 surfaces or detrital particles (Woyke et al. , 2009; Gómez Pereira et al. , 2012). Overall,
335 the findings indicate that TBDT systems, biopolymer degrading enzymes, and proteins
336 involved in attachment and colonization of cell and detrital surfaces are functionally very
337 important for the growth of Flavobacteria associated with phytoplankton in Newcomb
338 Bay, which is consistent with their inferred lifestyle in other cold and temperate marine
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339 waters (e.g ., Pinhassi et al. , 1999; Cottrell and Kirchman. 2000; Kirchman, 2002; Abell
340 and Bowman, 2005a,b; González et al. , 2008; Morris et al. , 2010; Williams et al. , 2012).
341 Glycolysis enzymes were detected with best matches to Flavobacteria and
342 Gammaproteobacteria (Table S1), suggesting that the degradation of complex 343 carbohydratesFor by the FlavobacteriaPeer increasesReview the availability Only and utilization of less 344 complex carbohydrates by other heterotrophs, as has been reported for bacterioplankton
345 communities in the North Sea (Teeling et al. , 2012). Based on amino acid catabolic
346 enzymes with closest matches to flavobacterial proteins (Table S1), glutamate and
347 aspartate appear to be the preferred amino acids for the Newcomb Bay Flavobacteria , as
348 found for the human oral commensal Bacteroidetes Porphyromonas gingivalis
349 (Takahashi et al. , 2000). Both amino acids can be converted into Krebs cycle
350 intermediates: glutamate is deaminated to 2 oxoglutarate by glutamate dehydrogenase,
351 and decarboxylated and activated to succinyl CoA by 2 oxoglutarate oxidoreductase, and
352 aspartate is transaminated to 2 oxoglutarate and glutamate by aspartate aminotransferase.
353 All three enzymes were detected in the metaproteome. Aspartate can also be deaminated
354 to fumarate, and then oxidized to acetate, or reduced to butyrate via succinyl CoA
355 (Takahashi et al. , 2000). The detection of proteins pertaining to both pathways (malate
356 dehydrogenase, butyryl CoA dehydrogenase) indicates that both oxidative and reductive
357 degradation was occurring, enabling redox balance to be maintained inside the cell.
358 Acetate generated from amino acid degradation by Flavobacteria is one potential source
359 of this substrate for SAR11; a predicted acetate/sodium symporter was detected for
360 SAR11 (Table S1).
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361 Although only one glutamine synthetase protein was detected in the metaproteome,
362 the gene for glutamine synthetase was the second most abundant type of gene identified
363 in the Newcomb Bay metagenome (Table 3). The deamination steps of amino acid
364 catabolism liberate ammonia, which implies, by virtue of their abundance, that the 365 FlavobacteriaFor perform Peer a potentially importantReview function in nitrog Onlyen cycling in the 366 Southern Ocean by generating ammonia from organic nitrogen. Certain marine
367 Flavobacteria have been shown to be unable to utilize ammonia as a nitrogen source
368 (Suzuki et al. , 2001), allowing this byproduct to be scavenged by other marine
369 microorganisms.
370
371 Uptake of labile solutes: ABC transporters were detected in the NB metaproteome for
372 multiple groups of Proteobacteria , including SAR11, Rhodobacterales , SAR116, and
373 various Gammaproteobacteria . Those with best matches to SAR11 had predicted
374 specificities for amino acids (especially branched chain amino acids), taurine,
375 polyamines, and carbohydrates (including glycerol 3 phosphate), although the majority
376 of the latter showed the best matches to Rhodobacterales (Tables 3 and S1). The ability
377 of Rhodobacterales to target common constituents of algal exudates such as taurine,
378 polyamines, and glycolate, and form commensal associations with phytoplankton
379 (Buchan et al. , 2005), is consistent with growth in Newcomb Bay using a broad range of
380 substrates (Brinkhoff et al. , 2008). This is in contrast to Polaribacter , which cannot
381 utilize these algal exudates (Gonzalez et al. , 2008). As a metabolite released by
382 phytoplankton during photorespiration, glycolate could be an important substrate for
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383 marine heterotrophic bacteria, particularly during the long period of solar radiation that
384 occurs at the surface of the Southern Ocean during the austral summer.
385 Other identified solute binding proteins belong to secondary uptake systems with
386 best matches to SAR11: tripartite ATP independent periplasmic (TRAP) transporters and 387 tripartite tricarboxylateFor Peer transporters (TTT)Review (Tables 3 and S1). Only In Gram negative bacteria, 388 the solute binding proteins accumulate in the periplasm and capture solutes that are
389 subsequently imported into the cytoplasm (Forward et al. , 1997; Winnen et al ., 2003).
390 These active uptake systems scavenge low concentrations of nutrients present in the
391 environment, and have been identified as abundant components of marine
392 metaproteomes, particularly for members of the Alphaproteobacteria (Sowell et al. ,
393 2009, 2011; Morris et al ., 2010; Williams et al. , 2012; Teeling et al. , 2012).
394 The NB metaproteome data indicates that at the time of sampling in Newcomb Bay
395 SAR116 targeted similar substrates to SAR11 using ABC and TRAP transporters (amino
396 acids, taurine, dicarboxylates). The NB metaproteome data also indicate that certain
397 members of Oceanospirillales +Alteromonadales use ABC transporters to target different
398 labile substrates to SAR11 and SAR116, with a preference for carbohydrates (including
399 glycerol 3 phosphate) (Tables 3 and S1). In addition, two ABC transporter proteins for
400 amino acids had best matches to Ant4D3 (Tables 3 and S1). Ant4D3 is an uncultured
401 Gammaproteobacteria lineage that was identified from fosmid data (Grzymski et al. ,
402 2006) and has been reported to be abundant in Antarctic Peninsula coastal waters (up to
403 10% of bacterioplankton) and actively incorporate amino acids (Grzymski et al. , 2006;
404 Straza et al. , 2010). Our data indicate that Ant4D3 is distributed, and likely active, in
405 Antarctic waters well beyond the Antarctic Peninsula.
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406
407
408 Responses to light and oxidative stress: The NB metaproteome included two
409 proteorhodopsins (Tables 3 and S1), photoactive cell membrane proteins from bacteria 410 and archaeaFor (Béjà et al.,Peer 2000, 2001; DeLongReview and Béjà, 2010). Only These had highest 411 sequence identities to proteorhodopsins from Polaribacter sp. MED52 and OMG. Both
412 had leucine at position 105 in the proteorhodopsin sequence, indicating spectral tuning to
413 an absorption maxima near 530nm (green light), consistent with responses to illumination
414 at or near the ocean surface (Gómez Consarnau et al. , 2007). The ability of
415 proteorhodopsin to function as a light driven proton pump for the generation of energy
416 for cell growth and maintenance (Gómez Consarnau et al. , 2007; Kimura et al. , 2011)
417 and enhanced utilization of organic matter for biosynthesis (Gonzalez et al. , 2008) should
418 enable the exploitation of light for photoheterotrophic growth during the Antarctic austral
419 summer.
420 High solar irradiance in aerobic surface waters can lead to oxidative stress, and
421 proteins involved in protection against damage caused by reactive oxygen species
422 (superoxide dismutase, peroxidase, thioredoxin, thioredoxin reductase,
423 alkylhydroperoxidase) were abundant, with most having best matches to Flavobacteria
424 (Table S1). The requirement for these enzymes may be exacerbated by the affinity that
425 Flavobacteria have for phytoplankton derived matter, which would be most abundant at
426 the ocean surface, and possibly also by exposure to regions of reduced salinity resulting
427 from the input of glacial and sea ice meltwater.
428
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429 Methylotrophy: Twelve proteins in the NB metaproteome were assigned to the
430 methanogenic archaeon Methanococcoides burtonii . These proteins were only able to be
431 identified because the complete genome of M. burtonii was available in the NR database.
432 In view of the absence of this taxon in the NB metagenome data, and the fact that there 433 were no peptideFor matches Peer in the AntComb Review database (Table S1 Only and S2), our data suggests 434 that this methanogen played only a minor role in the picoplankton community of
435 Newcomb Bay. Nevertheless, the presence of M. burtonii in surface waters of the
436 Southern Ocean is consistent with the identification of a methanogen affiliated with
437 Methanococcoides methylutens (a species that is phylogenetically closely related to M.
438 burtonii ; Thomas and Cavicchioli, 1998) in surface waters of the eastern Pacific Ocean,
439 which was proposed to survive in anoxic micro zones within detritus (Cynar and
440 Yayanos, 1991). M. burtonii is an anaerobic obligate methylotroph that was originally
441 isolated from anoxic sediments in a marine derived Antarctic lake (Franzmann et al. ,
442 1992). M. burtonii proteins detected from the Newcomb Bay sample include those
443 directly involved in the dismutation of the methylated substrates methanol and
444 trimethylamine to methane and CO 2 (Table S1). Methanol and trimethylamine (substrates
445 utilized by M. burtonii and M. methylutens ) have been implicated as important substrates
446 for bacterioplankton (Giovannoni et al., 2008; Chen et al. , 2011; Sowell et al. , 2011). In
447 addition to the methyltransferases assigned to M. burtonii , others (including a putative
448 trimethylamine methyltransferase) had best matches to OMG (Tables 3 and S1),
449 indicating possible methylotrophic behavior by this group of bacteria in Newcomb Bay.
450 The presence of these methyltransferases for methanogens and aerobic bacteria indicates
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451 that sufficient levels of substrate are present, presumably in particles, to permit both
452 anaerobic and aerobic methylotrophic growth.
453
454 455 ConclusionsFor Peer Review Only 456
457 The metagenomic survey of surface waters from 14 Southern Ocean sites confirms the
458 dominance of Flavobacteria , Alphaproteobacteria , and Gammaproteobacteria in these
459 waters, alongside groups that are not characteristic of picoplankton in more temperate
460 parts of the World Ocean, such as MGI and GSO EOSA 1. The abundance of
461 Flavobacteria positively correlated with chlorophyll a fluorescence, confirming a
462 relationship between primary productivity and Flavobacteria in polar waters.
463 Metaproteomic analysis of the Newcomb Bay site determined that Flavobacteria actively
464 deployed systems for the binding and exploitation of polymeric substrates, including
465 carbohydrates, polypeptides, and lipids; the dominant biopolymers within aggregates that
466 are derived from marine detritus (Alldredge, 1979). Algal derived polymers are utilized
467 by these heterotrophs, which in turn release simpler compounds (simple sugars, acetate,
468 ammonia) as byproducts that can be exploited by other microorganisms. The current
469 metaproteomic data corroborates the view that scavenging of nutrients by high affinity
470 uptake systems is a determining factor in microbial competition and survival, even in
471 relatively nutrient replete coastal ecosystems (Sowell et al. , 2011; Teeling et al. , 2012).
472 Having established the functional properties of these planktonic communities, we are
473 now in a position to analyze larger size fractions and examine the taxonomic and
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474 functional distinctions of particle associated and larger cell size communities associated
475 with algal blooms.
476
477 478 ExperimentalFor procedures Peer Review Only 479
480 Sample collection and GAAS analysis
481
482 Seawater samples from 14 sites in the Southern Ocean (Table 1, Fig. 1), representing
483 three East Antarctica sampling seasons, and including coastal samples, were collected
484 from surface waters (depths of 1 2 m). The microbial biomass from 200 L (samples from
485 January 2007) or 500 L (samples from December 2007, January 2008, October 2008 and
486 December 2008) of seawater was collected by sequential size fractionation through a 20
487 m prefilter on to filters (3.0, 0.8 and 0.1 m pore sized, 293 mm polyethersulfone
488 membrane filters), and filters placed into tubes containing storage buffer and
489 cryogenically preserved as described previously (Rusch et al., 2007; Ng et al. , 2010). In
490 this study, we present data for microorganisms that passed through the 0.8 µm filter and
491 were captured on the 0.1 µm filter. The sampling site characteristics for the Newcomb
492 Bay, sample (#235; Table 1, Fig. 1) were: 400 m from shore, water column depth 60 m
493 deep, mid day, clear skies, water temperature 0.65°C, air temperature 0.8°C, salinity
494 33.9%, fluorescence 8.6 g L 1, air pressure 737.7 mmHg.
495 To determine the OTU composition and relative abundances within each seawater
496 sample of archaea, bacteria and viruses (excluding eukaryotes), a database of genomes
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497 was prepared from the RefSeq microbial (bacteria and archaea) and viral databases
498 (release 41, retrieved May 31 2010 from ftp://ftp.ncbi.nih.gov/refseq/release/). Sequences
499 with the words “shotgun”, “contig”, “partial”, “end” or “part” in their headers were
500 excluded (after Angly et al ., 2009). The metagenomic reads were compared to this 501 database usingFor BLASTN Peer with default Reviewparameters (E value threshold Only 0.001). To minimize 502 spurious OTU identifications and increase the accuracy of relative abundance estimates, a
503 core set of most probable OTUs was identified with minspec which was developed based
504 on the approach used in minpath to reconstruct biochemical pathways (Ye and Doak,
505 2009; Wilkins et al. , unpublished results), and hits to OTUs not in the set were excluded
506 from the BLAST outputs. To determine relative abundances of OTUs, the perl script
507 GAAS (Angly et al. , 2009) was run on the BLAST output from each sample. To take into
508 account reads which did not yield high quality hits to any sequence in the reference
509 database, GAAS relative abundance estimates were scaled by the effective BLAST hit
510 rate for each sample. Because the RefSeq database did not include genomes for several
511 organisms that are likely to be abundant in Antarctic waters (Williams et al. , 2012), the
512 following genomic scaffolds were retrieved from Genbank and an additional database
513 constructed (Genbank accessions given in brackets): Neptuniibacter caesariensis MED92
514 (CH724125.1); Polaribacter irgensii 23 P (NZ_CH724148.1); Polaribacter sp. MED152
515 (AANA01000001.1 and AANA01000002.1); Psychroflexus torquis ATCC 700755
516 (CH959305.1); Ca. “Pelagibacter ubique” HTCC1002 (NZ_CH724130.1); Ca.
517 “Pelagibacter” sp. HTCC7211 (DS995298.1); alpha proteobacterium HTCC2255
518 (DS022282.1). BLAST comparisons and relative abundance estimations were performed
519 as above. While GAAS was designed for use only with complete reference genomes
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520 (Angly et al., 2009), the near completeness of the genomic scaffolds selected enhances
521 the reliability of the analysis using the additional genomic data. Only OTUs that had a
522 relative abundance of 0.02% or more in at least one of the samples were included. These
523 values correspond to relative abundances of cells within the samples. Data presented in 524 Table 1 wereFor subjected Peer to statistical analysisReview (Pearson Product Only Moment Correlation, 525 ANOVA regression analysis for statistical significance). The relative abundances of
526 individual groups (including logarithmically transformed data) were compared to one
527 another, as well as to known environmental parameters (collection date, latitude,
528 longitude, chlorophyll a fluorescence, distance from Antarctic landmass, and water
529 column depth).
530 For the Newcomb Bay site (#235; 0.1 m fraction; Table 1, Fig. 1), the SEED
531 database of translated genes was obtained from
532 ftp://ftp.theseed.org/subsystems/subsystems.complex on May 9 2012 and a BLAST
533 database constructed. Reads from the NB metagenome were compared to the SEED
534 database using blastx, with default parameters except for an E value threshold of 0.001.
535 The method of Coleman and Chisholm (2010) was adapted to count the number of hits to
536 genes in the database. For each read, if the top three hits (or all hits if fewer than three)
537 belonged to the same gene family with bit scores > 40, the read was annotated with that
538 gene. If there was a large (> 30) difference in bit score between hits, the lower scoring
539 hits were discarded. All identified genes with a relative abundance of at least 0.2% were
540 reported (Table 3; a complete list is in Table S3).
541
542 Metaproteomics
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543
544 Metaproteomic analysis of biomass extracted from the Newcomb Bay 0.1 m filter was
545 performed as described previously (Ng et al., 2010; Williams et al. , 2012). In brief, 20
546 mL lysis buffer contained 10 mM Tris EDTA (pH 8.0; Univar, Sydney, Australia), 20 L 547 of proteaseFor inhibitor cocktailPeer VI (Calbiochem, Review San Diego, CA), Only 0.1% sodium dodecyl 548 sulfate (Univar) and 1 mM dithiothreitol (Sigma Aldrich, Sydney, Australia). The only
549 methodological variation was the use of five rounds of sonication at 40 s intervals, 0.5
550 pulse on/0.5 pulse off, 20% amplitude, and a 3 kDa rather than 5 kDa Amicon filter unit.
551 Proteins were identified using two databases which contained sequences from archaea,
552 bacteria, viruses and eukaryotes: NR and AntComb (a customized Antarctic
553 metaproteome sequence database constructed from fosmid libraries and Southern Ocean
554 metagenome data) (Williams et al. , 2012). AntComb was constructed from: fosmid
555 libraries (IMG Acc: 2008193000, 2008193001, 2012990003, 2040502005 and
556 2040502004), individual marine microbial genomes (RefSeq Project ID: 202, 58903,
557 54247, 58401, 59427, 57855, 54575, 54169, 51877, 54583, 54265, 54403, 54255, 54577,
558 54163, 54227, 54185, 58403, 54207, 54205, 54623, 54467, 58597, 54183, 57863, 52598,
559 54259, 58183, 13044 and 51609) and Antarctic (Southern Ocean off East Antarctica)
560 metagenome samples (SRA Acc: SRX024734, SRX024735, SRX024799, SRX025108,
561 SRX024736 and SRX024800). MS/MS data analysis and validation of protein
562 identifications were performed as previously described (Ng et al ., 2010) except that the
563 databases used were NR and AntComb (Williams et al. , 2012). Mascot searches with a
564 false discovery rate 45% were rejected. All other Mascot results were combined and
565 validated using a MudPit analysis in Scaffold 3.0 (Proteome Software Inc., Portland, OR,
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566 USA) using the following parameters: minimal probability of peptide identification, 95%;
567 minimal probability of protein identification, 99%. Protein matches were only accepted if
568 they were identified by a minimum of two unique peptides. All proteins were manually
569 annotated using BLASTP, and the protein that showed the highest sequence identity was 570 recorded, includingFor the Peer organism name Review (Table S1). The NB metaproteomeOnly was defined 571 by all proteins that were detected with matches to bacteria, archaea and viruses
572 (excluding eukaryotes).
573
574 Acknowledgments
575
576 This work was supported by the Australian Research Council and the Australian
577 Antarctic Division. Mass spectrometric results were obtained at the Bioanalytical Mass
578 Spectrometry Facility within the Analytical Centre of the University of New South
579 Wales. This work was undertaken using infrastructure provided by NSW Government co
580 investment in the National Collaborative Research Infrastructure Scheme. Subsidized
581 access to this facility is gratefully acknowledged. The authors acknowledge assistance
582 during sample collection by Torsten Thomas and Jeffrey Hoffman, support from the J.
583 Craig Venter Institute and the Gordon and Betty Moore Foundation, insightful
584 discussions with Simon Wright, and assistance from David Smith and Henk Brolsma for
585 generating the bathymetry image of the sampling site.
586
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587 References
588
589 Abell, G.C.J., and Bowman, J.P. (2005a) Ecological and biogeographic relationships of
590 class Flavobacteria in the Southern Ocean. FEMS Microbiol Ecol 51: 265 277. 591 Abell, G.C.J.For and Bowman, Peer J.P. (2005b) Review Colonization and community Only dynamics of class 592 Flavobacteria on diatom detritus in experimental mesocosms based on Southern
593 Ocean seawater. FEMS Microbiol Ecol 53: 379 391.
594 Alldredge, A.L. (1979) The chemical composition of macroscopic aggregates in two
595 neretic seas. Limnol Oceanogr 24: 855 866.
596 Angly, F.E., Willner, D., Prieto Davó, A., Edwards, R.A., Schmieder, R., Vega Thurber,
597 R., et al. (2009) The GAAS metagenomic tool and its estimations of viral and
598 microbial average genome size in four major biomes. PLoS Comput Biol 5:
599 e1000593.
600 Béjà, O., Aravind, L., Koonin, E.V., Suzuki, M.T., Hadd, A., Nguyen, L.P., et al. (2000)
601 Bacterial rhodopsin: evidence for a new type of phototrophy in the sea. Science 289:
602 1902 1906.
603 Béjà, O., Spudich, E.N., Spudich, J.L., Leclerc, M., and DeLong, E.F. (2001)
604 Proteorhodopsin phototrophy in the ocean. Nature 411: 786 789.
605 Berg, I.A., Kockelkorn, D., Buckel, W., and Fuchs, G. (2007) A 3 hydroxypropionate/4
606 hydroxybutyrate autotrophic carbon dioxide assimilation pathway in Archaea.
607 Science 318: 1782 1786.
28
Wiley-Blackwell and Society for Applied Microbiology Page 29 of 165
608 Bowman, J.P., and McCuaig, R.D. (2003) Biodiversity, community structural shifts, and
609 biogeography of prokaryotes within Antarctic continental shelf sediment. Appl
610 Environ Microbiol 69: 2463 2483.
611 Bowman, J.P., McCammon, S.A., Brown, M.V., Nichols, D.S., and McMeekin, T.A. 612 (1997)For Diversity andPeer association ofReview psychrophilic bacteria Only in Antarctic sea ice. Appl 613 Environ Microbiol 63: 3068 3078.
614 Boyd, P.W., and Ellwood, M.J. (2010) The biogeochemical cycle of iron in the ocean.
615 Nature Geosci 3: 675–682.
616 Brinkhoff, T., Giebel, H.A., and Simon, M. (2008) Diversity, ecology, and genomics of
617 the Roseobacter clade: a short overview. Arch Microbiol 189: 531 539.
618 Brown, M.V., and Bowman J.P. (2001) A molecular phylogenetic survey of sea ice
619 microbial communities (SIMCO). FEMS Microbiol Ecol 35: 267 275.
620 Brown, M.V., Philip, G.K., Bunge, J.A., Smith, M.C., Bissett, A., Lauro, F.M., et al.
621 (2009) Microbial community structure in the North Pacific Ocean. ISME J 3: 1374
622 1386.
623 Buchan, A., González, J.M., and Moran, M.A. (2005) Overview of the marine
624 Roseobacter lineage. Appl Environ Microbiol 71: 5665–5677.
625 Canfield, D.E., Stewart, F.J., Thamdrup, B., De Brabandere, L., Dalsgaard, T., Delong, et
626 al. (2010) A cryptic sulfur cycle in oxygen minimum zone waters off the Chilean
627 coast. Science 330: 1375 1378.
628 Chen, Y., Patel, N.A., Crombie, A., Scrivens, J.H., and Murrell, J.C. (2011) Bacterial
629 flavin containing monooxygenase is trimethylamine monooxygenase. Proc Natl
630 Acad Sci U S A 108: 17791 17796.
29
Wiley-Blackwell and Society for Applied Microbiology Page 30 of 165
631 Cho, J.C., and Giovannoni, S.J. (2004) Cultivation and growth characteristics of a diverse
632 group of oligotrophic marine Gammaproteobacteria . Appl Environ Microbiol 70:
633 432 440.
634 Coleman, M.L., and Chisholm, S.W. (2010) Ecosystem specific selection pressures 635 revealedFor through comparativePeer population Review genomics. Proc Only Natl Acad Sci U S A 107 : 636 18634 18639.
637 Cottrell, M. T., and Kirchman, D. L. (2000) Natural assemblages of marine
638 proteobacteria and members of the Cytophaga-Flavobacter cluster consuming low
639 and high molecular weight dissolved organic matter. Appl Environ Microbiol 66:
640 1692–1697.
641 Cynar, F.J., and Yayanos, A.A. (1991) Enrichment and characterization of a
642 methanogenic bacterium from the oxic upper layer of the ocean. Curr Microbiol 23:
643 89 96.
644 DeLong, E.F., Franks, D.G., and Alldredge, A.L. (1993) Phylogenetic diversity of
645 aggregate attached vs. free living marine bacterial assemblages. Limnol Oceanogr
646 38: 924–934.
647 DeLong, E.F., and Béjà, O. (2010) The light driven proton pump proteorhodopsin
648 enhances bacterial survival during tough times. PLoS Biol 8: e1000359.
649 Fandino, L., Riemann, L., Steward, G., and Azam, F. (2005) Population dynamics of
650 Cytophaga-Flavobacteria during marine phytoplankton blooms analyzed by real
651 time quantitative PCR. Aquat Microb Ecol 40: 251–257.
652 Forward, J.A., Behrendt, M.C., Wyborn, N.R., Cross, R., and Kelly, D.J. (1997) TRAP
653 transporters: a new family of periplasmic solute transport systems encoded by the
30
Wiley-Blackwell and Society for Applied Microbiology Page 31 of 165
654 dctPQM genes of Rhodobacter capsulatus and by homologs in diverse gram
655 negative bacteria. J Bacteriol 179: 5482–5493.
656 Franzmann, P.D., Springer, N., Ludwig, W., Conway De Macario, E., and Rohde, M.
657 (1992) A methanogenic archaeon from Ace Lake, Antarctica: Methanococcoides 658 burtoniiFor sp. nov. SystemPeer Appl Microbiol Review 15: 573–581. Only 659 Galand, P.E., Lovejoy, C., Pouliot, J., and Vincent, W.F. (2008) Heterogeneous archaeal
660 communities in the particle rich environment of an arctic shelf ecosystem. J Marine
661 Syst 74: 774–782.
662 Galand, P.E., Casamayor, E.O., Kirchman, D.L., Potvin, M., and Lovejoy, C. (2009)
663 Unique archaeal assemblages in the Arctic Ocean unveiled by massively parallel tag
664 sequencing. ISME J 3: 860–869.
665 Ghiglione, J.F., and Murray, A.E. (2012) Pronounced summer to winter differences and
666 higher wintertime richness in coastal sub Antarctic and Antarctic marine
667 bacterioplankton. Environ Microbiol 14: 617 629.
668 Gilbert, H.J. (2008) Sus out sugars in. Structure 16: 987 989.
669 Giovannoni, S.J., Tripp, H.J., Givan, S., Podar, M., Vergin, K.L., Baptista, D., et al.
670 (2005) Genome streamlining in a cosmopolitan oceanic bacterium. Science 309:
671 1242 1245.
672 Giovannoni, S.J., Hayakawa, D.H., Tripp, H.J., Stingl, U., Givan, S.A., Cho, J.C., et al.
673 (2008) The small genome of an abundant coastal ocean methylotroph. Environ
674 Microbiol 10: 1771–1782.
31
Wiley-Blackwell and Society for Applied Microbiology Page 32 of 165
675 Glöckner, F.O., Fuchs, B.M., and Amann, R. (1999) Bacterioplankton compositions of
676 lakes and oceans: a first comparison based on fluorescence in situ hybridization. Appl
677 Environ Microbiol 65: 3721–3726.
678 Gómez Consarnau, L., González, J.M., Coll Lladó, M., Gourdon, P., Pascher, T., Neutze, 679 R., et al.For (2007) LightPeer stimulates Reviewgrowth of proteorhodopsin Onlycontaining marine 680 Flavobacteria . Nature 445: 210–213.
681 Gómez Pereira, P.R., Schüler, M., Fuchs, B.M., Bennke, C., Teeling, H., Waldmann, J.,
682 et al . (2012) Genomic content of uncultured Bacteroidetes from contrasting oceanic
683 provinces in the North Atlantic Ocean. Environ Microbiol 14: 52 66.
684 González, J.M., Fernández Gómez, B., Fernàndez Guerra, A., Gómez Consarnau, L.,
685 Sánchez, O., Coll Lladó, M., et al. (2008) Genome analysis of the proteorhodopsin
686 containing marine bacterium Polaribacter sp. MED152 ( Flavobacteria ). Proc Natl
687 Acad Sci U S A 105: 8724 8729.
688 Grossart, H.P., Levold, F., Allgaier, M., Simon, M., and Brinkhoff T. (2005) Marine
689 diatom species harbour distinct bacterial communities. Environ Microbiol. 7: 860
690 873.
691 Grzymski, J.J., Riesenfeld, C.S., Williams, T.J., Dussaq, A.M., Ducklow, H., Erickson,
692 M., et al. (2012) A metagenomic assessment of winter and summer bacterioplankton
693 from Antarctica Peninsula coastal surface waters. ISME J . doi:
694 10.1038/ismej.2012.31. [Epub ahead of print]
695 Grzymski, J.J., Carter, B.J., DeLong, E.F., Feldman, R.A., Ghadiri, A., and Murray, A.E.
696 (2006) Comparative genomics of DNA fragments from six Antarctic marine
697 planktonic bacteria. Appl Environ Microbiol 72: 1532 1241.
32
Wiley-Blackwell and Society for Applied Microbiology Page 33 of 165
698 Horner Devine, C.M., Leibold, M.A., Smith, V.H. and Bohannan, B.J.M. (2003)
699 Bacterial diversity patterns along a gradient of primary productivity. Ecol Lett 6:
700 613–622.
701 Jamieson, R.E., Rogers, A.D., Billett, D.S., Smale, D.A., and Pearce, D.A. (2012) 702 PatternsFor of marine Peer bacterioplankton Review biodiversity in the surfaceOnly waters of the Scotia 703 Arc, Southern Ocean. FEMS Microbiol Ecol 2012 Jan 24. doi: 10.1111/j.1574
704 6941.2012.01313.x. [Epub ahead of print]
705 Kalanetra, K.M., Bano, N., and Hollibaugh, J.T. (2009) Ammonia oxidizing Archaea in
706 the Arctic Ocean and Antarctic coastal waters. Environ Microbiol 11: 2434 2445.
707 Kimura, H., Young, C.R., Martinez, A., and Delong, E.F. (2011) Light induced
708 transcriptional responses associated with proteorhodopsin enhanced growth in a
709 marine flavobacterium. ISME J 5: 1641 1651.
710 Kirchman, D.L. (2002) The ecology of Cytophaga-Flavobacteria in aquatic
711 environments. FEMS Microbiol Ecol 39: 91–100.
712 Könneke, M., Bernhard, A.E., de la Torre, J.R., Walker, C.B., Waterbury, J.B., and Stahl
713 DA (2005) Isolation of an autotrophic ammonia oxidizing marine archaeon. Nature
714 437: 543–546.
715 Kuwahara, H., Takaki, Y., Shimamura, S., Yoshida, T., Maeda, T., Kunieda, T., and
716 Maruyama, T. (2011) Loss of genes for DNA recombination and repair in the
717 reductive genome evolution of thioautotrophic symbionts of Calyptogena clams.
718 BMC Evol Biol 11: 285.
719 Marshall, K.T., and Morris, R.M. (2012) Isolation of an aerobic sulfur oxidizer from the
720 SUP05/Arctic96BD 19 clade. ISME J. 2012 Aug 9. doi: 10.1038/ismej.2012.78.
33
Wiley-Blackwell and Society for Applied Microbiology Page 34 of 165
721 McBride, M.J. (2001) Bacterial gliding motility: Multiple mechanisms for cell movement
722 over surfaces. Annu Rev Microbiol 55: 49 75.
723 Merbt, S.N., Stahl, D.A., Casamayor, E.O., Martí, E., Nicol, G.W., and Prosser, J.I.
724 (2011) Differential photoinhibition of bacterial and archaeal ammonia oxidation. 725 FEMSFor Microbiol LettPeer 327: 41 46. Review Only 726 Moore, K.J., and Abbott, M.R. (2000) Phytoplankton chlorophyll distributions and
727 primary production in the Southern Ocean. J Geophys Res 105: 709 728.
728 Moran, M.A., Belas, R., Schell, M.A., González, J.M., Sun, F., Sun, S., et al. (2007)
729 Ecological genomics of marine Roseobacters. Appl Environ Microbiol 73: 4559
730 4569.
731 Morris, R.M., Rappé, M.S., Connon, S.A., Vergin, K.L., Siebold, W.A., Carlson, C.A.,
732 and Giovannoni, S.J. (2002) SAR11 clade dominates ocean surface bacterioplankton
733 communities. Nature 420: 806 810.
734 Morris, R.M., Nunn, B.L., Frazar, C., Goodlett, D.R., Ting, Y.S., and Rocap, G. (2010)
735 Comparative metaproteomics reveals ocean scale shifts in microbial nutrient
736 utilization and energy transduction. ISME J 4: 673 685.
737 Mou, X., Sun, S., Edwards, R.A., Hodson, R.E., and Moran, M.A. (2008) Bacterial
738 carbon processing by generalist species in the coastal ocean. Nature 451: 708 711.
739 Murray, A.E., and Grzymski, J.J. (2007) Diversity and genomics of Antarctic marine
740 micro organisms. Philos Trans R Soc Lond B Biol Sci 362: 2259 2271.
741 Musat, N., Halm, H., Winterholler, B., Hoppe, P., Peduzzi, S., Hillion, F., et al. (2008) A
742 single cell view on the ecophysiology of anaerobic phototrophic bacteria. Proc Natl
743 Acad Sci U S A 105: 17861–17866.
34
Wiley-Blackwell and Society for Applied Microbiology Page 35 of 165
744 Newton, I.L., Woyke, T., Auchtung, T.A., Dilly, G.F., Dutton, R.J., Fisher, M.C., et al .
745 (2007) The Calyptogena magnifica chemoautotrophic symbiont genome. Science
746 315: 998 1000.
747 Ng, C., DeMaere, M.Z., Williams, T.J., Lauro, F.M., Raftery, M., Gibson, J.A., et al. 748 (2010)For Metaproteogenomic Peer analysis Review of a dominant green Only sulfur bacterium from Ace 749 Lake, Antarctica. ISME J 4: 1002 1019.
750 Oh, H.M., Kwon, K.K., Kang, I., Kang, S.G., Lee, J.H., Kim, S.J., and Cho, J.C. (2010)
751 Complete genome sequence of “ Candidatus Puniceispirillum marinum” IMCC1322,
752 a representative of the SAR116 clade in the Alphaproteobacteria . J Bacteriol 192:
753 3240 3241.
754 O’Sullivan, L.A., Fuller, K.E., Thomas, E.M., Turley, C.M., Fry, J.C., and Weightman,
755 A.J. (2004) Distribution and culturability of the uncultivated ‘AGG58 cluster’ of the
756 Bacteroidetes phylum in aquatic environments. FEMS Microbiol Ecol 47: 359–370.
757 Pinhassi, J., Azam, F., Hemphala, J., Long, R.A., Martinez, J., Zweifel, U.L., and
758 Hagstrom, Å. (1999) Coupling between bacterioplankton species composition,
759 population dynamics, and organic matter degradation. Aquat Microb Ecol 17: 13–26
760 Pinhassi, J., Sala, M.M., Havskum, H., Peters, F., Guadayol, O., Malits, A., and Marrasé,
761 C. (2004) Changes in bacterioplankton composition under different phytoplankton
762 regimens. Appl Environ Microbiol 70: 6753 6766.
763 Piquet, A.M., Bolhuis, H., Meredith, M.P., and Buma, A.G. (2011) Shifts in coastal
764 Antarctic marine microbial communities during and after melt water related surface
765 stratification. FEMS Microbiol Ecol 76: 413 427.
35
Wiley-Blackwell and Society for Applied Microbiology Page 36 of 165
766 Rath, J., Wu, K.Y., Herndl, G.J., and DeLong, E.F. (1998) High phylogenetic diversity in
767 a marine snow associated bacterial assemblage. Aquat Microb Ecol 14: 261–269.
768 Reeves, A.R., Wang, G. R., and Salyers, A.A. (1997) Characterization of four outer
769 membrane proteins that play a role in utilization of starch by Bacteroides 770 thetaiotaomicronFor . PeerJ Bacteriol 179: Review 643–649. Only 771 Rusch, D.B., Halpern, A.L., Sutton, G., Heidelberg, K.B., Williamson, S., Yooseph, S., et
772 al. (2007) The Sorcerer II Global Ocean Sampling expedition: northwest Atlantic
773 through eastern tropical Pacific. PLoS Biol . 5: e77.
774 Simon, M., Glöckner, F.O., and Amann, R. (1999) Different community structure and
775 temperature optima of heterotrophic picoplankton in various regions of the Southern
776 Ocean. Aquat Microb Ecol 18: 275–284
777 Sowell, S.M., Wilhelm, L.J., Norbeck, A.D., Lipton, M.S., Nicora, C.D., Barofsky, D.F.,
778 et al. (2009) Transport functions dominate the SAR11 metaproteome at low nutrient
779 extremes in the Sargasso Sea. ISME J 3: 93 105.
780 Sowell, S.M., Abraham, P.E., Shah, M., Verberkmoes, N.C., Smith, D.P., Barofsky, D.F.,
781 and Giovannoni, S.J. (2011) Environmental proteomics of microbial plankton in a
782 highly productive coastal upwelling system. ISME J 5: 856 865.
783 Straza, T.R.A., Ducklow, H.W., Murray, A.E., and Kirchman, D.L. (2010) Abundance
784 and single cell activity of bacterial groups in Antarctic coastal waters. Limnol
785 Oceanogr 55: 2526 2536.
786 Suzuki, M., Nakagawa, Y., Harayama, S., and Yamamoto S. (2001) Phylogenetic
787 analysis and taxonomic study of marine Cytophaga like bacteria: proposal for
788 Tenacibaculum gen. nov. with Tenacibaculum maritimum comb. nov. and
36
Wiley-Blackwell and Society for Applied Microbiology Page 37 of 165
789 Tenacibaculum ovolyticum comb. nov., and description of Tenacibaculum
790 mesophilum sp. nov. and Tenacibaculum amylolyticum sp. nov. Int J Syst Evol
791 Microbiol 51: 1639 1652.
792 Swan, B.K., Martinez Garcia, M., Preston, C.M., Sczyrba, A., Woyke, T., Lamy, D., et 793 al . (2011)For Potential Peer for chemolithoautotrophy Review among u biquitousOnly bacteria lineages in 794 the dark ocean. Science 333: 1296 1300.
795 Takahashi, N., Sato, T., and Yamada, T. (2000) Metabolic pathways for cytotoxic end
796 product formation from glutamate and aspartate containing peptides by
797 Porphyromonas gingivalis . J Bacteriol 182: 4704 4710.
798 Teeling, H., Fuchs, B.M., Becher, D., Klockow, C., Gardebrecht, A., Bennke, C.M., et al.
799 (2012) Substrate controlled succession of marine bacterioplankton populations
800 induced by a phytoplankton bloom. Science 336: 608 611.
801 Thomas, T., and Cavicchioli, R. (1998) Archaeal cold adapted proteins: structural and
802 evolutionary analysis of the elongation factor 2 proteins from psychrophilic,
803 mesophilic and thermophilic methanogens. FEBS Lett 439: 281 286.
804 West, N.J., Obernosterer, I, Zemb, O., and Lebaron, P. (2008) Major differences of
805 bacterial diversity and activity inside and outside of a natural iron fertilized
806 phytoplankton bloom in the Southern Ocean. Environ Microbiol 10: 738 756.
807 Wagner Döbler, I., and Biebl, H. (2006) Environmental biology of the marine
808 Roseobacter lineage. Annu Rev Microbiol 60: 255–280.
809 Walsh, D.A., Zaikova, E., Howes, C.G., Song, Y.C., Wright, J.J., Tringe, S.G., et al.
810 (2009) Metagenome of a versatile chemolithoautotroph from expanding oceanic dead
811 zones. Science 326: 578 582.
37
Wiley-Blackwell and Society for Applied Microbiology Page 38 of 165
812 West, N.J., Obernosterer, I., Zemb, O., and Lebaron, P. (2008) Major differences of
813 bacterial diversity and activity inside and outside of a natural iron fertilized
814 phytoplankton bloom in the Southern Ocean. Environ Microbiol 10: 738 756.
815 Williams, K.P., Gillespie, J.J., Sobral, B.W., Nordberg, E.K., Snyder, E.E., Shallom, 816 J.M., andFor Dickerman, Peer A.W. (2010) Review Phylogeny of Gammaproteobacteria Only . J Bacteriol 817 192: 2305 2314.
818 Williams, T.J., Long, E., Evans, F., Demaere, M.Z., Lauro, F.M., Raftery, M.J., et al.
819 (2012) A metaproteomic assessment of winter and summer bacterioplankton from
820 Antarctic Peninsula coastal surface waters. ISME J. doi: 10.1038/ismej.2012.28.
821 [Epub ahead of print]
822 Winnen, B., Hvorup, R.N., and Saier, M.H. Jr. (2003) The tripartite tricarboxylate
823 transporter (TTT) family. Res Microbiol 154: 457–465.
824 Woyke, T., Xie, G., Copeland, A., González, J.M., Han, C., Kiss, H., et al. (2009)
825 Assembling the marine metagenome, one cell at a time. PLoS One 4: e5299.
826 Wright, S.W., van den Enen, R.L., Pearce, I., Davidson, A.T., Scott, F.J., and Westwood,
827 K.J. (2010) Phytoplankton community structure and stocks in the Southern Ocean
828 (30 80°E) determined by CHEMTAX analysis of HPLC pigment signatures. Deep-
829 Sea Res II 57: 758 778.
830 Wuchter, C., Abbas, B., Coolen, M.J.L., Herfort, L., van Bleijswijk, J., Timmers, P., et al .
831 (2006) Archaeal nitrification in the ocean. Proc Natl Acad Sci U S A 103: 12317–
832 12322.
38
Wiley-Blackwell and Society for Applied Microbiology Page 39 of 165
833 Ye, Y., and Doak, T.G. (2009). A parsimony approach to biological pathway
834 reconstruction/inference for genomes and metagenomes. PLoS Comp Biol 5:
835 e1000465.
836 837 SupportingFor information Peer Review Only 838
839 Additional Supporting Information may be found in the online version of this article:
840
841 Table S1. Complete list of bacterial and archaeal proteins identified in the NB
842 metaproteome.
843
844 Table S2. Counts for unique peptides and assigned spectra for proteins identified using
845 the NR database, and a customized Antarctic database “AntComb”, which was
846 constructed from fosmid libraries and Southern Ocean metagenome data.
847
848 Table S3. All genes identified in the NB metagenome (excel file).
849
850
851 Figure legends
852
853 Fig. 1. Southern Ocean sampling sites. A) The location of the 14 East Antarctica,
854 Southern Ocean samples used for metagenomic analysis. Inset: expanded view showing
855 the location of sample #235 in Newcomb Bay. B) Location of sampling site #235 in
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856 Newcomb Bay, showing bathymetry. Map produced by the Australian Antarctic Data
857 Centre. C) Photograph of Newcomb Bay January 3, 2007 with the RV Aurora Australis
858 anchored in the approximate location where the water for #235 was sampled.
859 860 Fig. 2. RelativeFor abundance Peer of Flavobacteria Review and SAR11 with Only chlorophyll a 861 concentration. Flavobacteria (diamonds); SAR11 (circles).
862
863 Fig. 3. Taxonomy of bacteria and archaea from NB metagenome and NB metaproteome.
864 A) Phylogenetic assignment of OTU matches to the NB metagenome based on GAAS
865 analysis. Not shown: SAR116 (0.03%), other Alphaproteobacteria (0.1%), OMG
866 (0.02%). B) Phylogenetic assignment of NB metaproteome based on best matches of
867 identified proteins to different groups. C) Phylogenetic assignment of NB metaproteome
868 based on assigned spectra to AntComb, a customized Antarctic metaproteome sequence
869 database constructed from fosmid libraries and Southern Ocean metagenome data.
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Table 1. Relative abundance of different phylogenetic groups in 14 East Antarctica, Southern Ocean metagenomes as determined by GAAS
analysis. Data known for each of the sites at the time of collection is provided. NR indicates data not recorded. MGI, Marine Group I Crenarchaeota . Oceano +ForAltero , Oceanospirillales Peer+Alteromonadales Review. OMG, Oligotrophic Marine Only Gammaproteobacteria .
Relative abundance (%) Altero Sample date Collection Location ( g/L) escence Fluor (km) Distance depth(m) Water bacteria Flavo- SAR11 bacterales Rhodo- EOSA 1 GSO OMG Oceano+ SAR116 MGI
235 66 16.1 S, (Newcomb Jan 01, 2007 8.6 0.4 60 50.393 36.857 0.233 1.662 0.020 0.602 0.031 4.384 110 32.0 E Bay) 63 52.72 S, 236 Jan 07, 2007 12.1 214 2500 37.981 57.089 0.5 1.001 0.014 0.341 0.027 0.003 112 4.2 E 66 33.26 S, 351 Dec 28, 2007 1.3 31.4 823 6.306 80.422 0.606 3.793 0.022 0.536 0.056 0.58 143 19.62 E 66 45.451 S, 352 Dec 29, 2007 3.1 9.4 164 6.164 82.072 0.853 3.941 0.027 0.625 0.051 0.895 143 17.222 E 67 2.564 S, 353 Dec 30, 2007 0.3 4.7 180 3.166 73.392 0.668 4.882 0.039 0.661 0.085 10.185 144 40.065 E 66 44.85 S, 355 Jan 03, 2008 7.4 25.3 920 11.911 78.097 0.481 5.272 0.014 0.482 0.041 0.081 144 19.53 E 66 10.157 S, 357 Jan 05, 2008 2.5 78.4 580 17.444 67.164 3.786 3.788 0.058 2.169 0.128 0.064 142 55.56 E 64 18.002 S, 358 Jan 09, 2008 0.45 395 3550 7.215 82 4.76 1.367 0.036 0.675 0.104 0.004 150 0.167 E 66 10.708 S, 359 Jan 12, 2008 2.5 71.2 540 18.319 65.999 3.698 3.877 0.085 2.067 0.148 0.157 143 29.25 E 66 33.95 S, 360 Jan 13, 2008 6.2 16.6 316 17.081 68.497 1.072 5.67 0.028 0.969 0.086 0.437 140 51.933 E 65 32.101 S, 362 Jan 19, 2008 0.5 129 1064 4.657 91.228 1.417 0.279 0.0045 0.077 0.028 0.005 140 42.702 E 63 48.54 S, 388 Oct 20, 2008 1.5 241 3.992 79.972 0.417 5.133 0.027 0.279 0.071 3.679 115 9.7 E NR 64 48.1 S, 389 Oct 22, 2008 0.14 111 2.358 57.71 7.736 2.788 0.032 0.587 0.07 6.14 112 22.4 E NR 68 23.393 S, 391 Dec 12, 2008 5 57.8 378 11.971 65.956 0.849 7.936 0.062 1.185 0.095 2.065 76 39.91 E
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Table 2. Proteins detected in the Newcomb Bay metaproteome that are discussed in the main text. Proteins are arranged according to phylogenetic grouping, with the number of detected orthologs given for each. The full list of proteins is provided in Table S1.
For Peer ReviewPhylogenetic Only group
/ /
Protein SAR11 SAR11 Oceanospirillales OMG SAR116 Ant4D3 Methanogenic Bacteroidetes Alteromonadales Rhodobacterales Euryarchaeota
TonB dependent receptor (e.g., SusC, RagA) 30 1 2
Outer membrane binding protein (e.g., SusD, RagB) 8
Biopolymer transport, protein channel 3 1
Glycosyl hydrolase 6
Aminopeptidase 3 1
Gliding motility protein 3
ABC transport system, general amino acid binding protein 2 1 1
ABC transport system, glycine betaine binding protein 2 1
ABC transport system, branched chain amino acids binding protein 2 5
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ABC transport system, glutamate/glutamine/aspartate/asparagine binding 1 protein
ABC transport system, taurine/sulfonate binding protein 2 1 1
ABC transport system, spermidine/putrescine bindingFor proteinPeer Review 2 3 Only
ABC transport system, sugar binding protein 1 6 2
ABC transport system, glycerol 3 phosphate binding protein 4 1
TRAP transporter, DctP binding subunit / TRAP associated 4 4 2 extracytoplasmic immunity (TAXI) protein
TTT transporter, TctC binding subunit 1
Proteorhodopsin 1 1
Trimethylamine methyltransferase 1 1
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Table 3. Gene count for genes from the Newcomb Bay metagenome. Only genes that had a relative abundance of 0.2% or more are shown. The full list of genes is provided in Table S3. For Peer Review Only Gene Count % Function TonB dependent receptor 1050 1.77 Macromolecular transport, including biopolymers Glutamate synthase [NADPH] large chain (EC 1.4.1.13) 290 0.49 Ammonia assimilation / amino acid metabolism Permease of the drug/metabolite transporter (DMT) superfamily 280 0.47 Macromolecular transport, including biopolymers 3 oxoacyl [acyl carrier protein] reductase (EC 1.1.1.100) 261 0.44 Fatty acid metabolism DNA directed RNA polymerase beta subunit (EC 2.7.7.6) 245 0.41 Transcription DNA polymerase III alpha subunit (EC 2.7.7.7) 241 0.41 Transcription DNA directed RNA polymerase beta' subunit (EC 2.7.7.6) 237 0.4 Transcription DNA polymerase I (EC 2.7.7.7) 213 0.36 Transcription Aspartate aminotransferase (EC 2.6.1.1) 208 0.35 Amino acid metabolism Sarcosine oxidase alpha subunit (EC 1.5.3.1) 202 0.34 Amino acid metabolism / C1 metabolism Isoleucyl tRNA synthetase (EC 6.1.1.5) 193 0.33 Translation (tRNA biosynthesis) Aldehyde dehydrogenase (EC 1.2.1.3) 183 0.31 General carbon metabolism Long chain fatty acid CoA ligase (EC 6.2.1.3) 182 0.31 Fatty acid metabolism Enoyl CoA hydratase (EC 4.2.1.17) 171 0.29 Fatty acid metabolism or 3 hydroxypropionate/4 hydroxybutyrate cycle Protein export cytoplasm protein SecA ATPase RNA helicase (TC 3.A.5.1.1) 170 0.29 Protein secretion Leucyl tRNA synthetase (EC 6.1.1.4) 169 0.29 Translation (tRNA biosynthesis) Alanyl tRNA synthetase (EC 6.1.1.7) 168 0.28 Translation (tRNA biosynthesis) D 3 phosphoglycerate dehydrogenase (EC 1.1.1.95) 167 0.28 Amino acid metabolism / C1 metabolism Acriflavin resistance protein 166 0.28 Transport (efflux pump) Translation initiation factor 2 165 0.28 Translation Ribonucleotide reductase of class Ia (aerobic); alpha subunit (EC 1.17.4.1) 165 0.28 DNA synthesis and repair DNA topoisomerase I (EC 5.99.1.2) 160 0.27 DNA replication Sulfate permease 159 0.27 Transport (sulfte import or efflux) Dihydroorotase (EC 3.5.2.3) 159 0.27 Pyrimidine biosynthesis
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DNA gyrase subunit A (EC 5.99.1.3) 156 0.26 DNA replication Methylmalonyl CoA mutase (EC 5.4.99.2) 155 0.26 General carbon metabolism or 3 hydroxypropionate/4 hydroxybutyrate cycle Flagellar hook length control protein FliK 153 0.26 Flagella biosynthesis Carbamoyl phosphate synthase large chain (EC 6.3.5.5) 151 0.25 Pyrimidine biosynthesis / Amino acid metabolism 2 oxoglutarate dehydrogenase E1 componentFor (EC 1.2.4.2) Peer 150 Review 0.25 Krebs cycle Only GMP synthase [glutamine hydrolyzing] (EC 6.3.5.2) 147 0.25 Nucleotide metabolism Excinuclease ABC subunit A 145 0.24 DNA repair Cold shock DEAD box protein A 145 0.24 Cold stress (RNA chaperones) Polyribonucleotide nucleotidyltransferase (EC 2.7.7.8) 143 0.24 Degradosome (RNA degradation) Thioredoxin reductase (EC 1.8.1.9) 142 0.24 Oxidative stress ATP synthase beta chain (EC 3.6.3.14) 139 0.23 Energy metabolism Acetyl coenzyme A synthetase (EC 6.2.1.1) 139 0.23 General carbon metabolism Cell division protein FtsH (EC 3.4.24. ) 139 0.23 Cell replication O succinylhomoserine sulfhydrylase (EC 2.5.1.48) 138 0.23 Sulfur metabolism / amino acid metabolism DNA gyrase subunit B (EC 5.99.1.3) 136 0.23 DNA replication Aspartyl tRNA(Asn) synthetase (EC 6.1.1.23) 136 0.23 Translation (tRNA biosynthesis) Homoserine dehydrogenase (EC 1.1.1.3) 133 0.22 Amino acid metabolism Transcription repair coupling factor 133 0.22 DNA repair Acetyl CoA acetyltransferase (EC 2.3.1.9) 131 0.22 Fatty acid metabolism Valyl tRNA synthetase (EC 6.1.1.9) 130 0.22 Translation (tRNA biosynthesis) Chaperone protein DnaK 129 0.22 Protein chaperone and repair RNA polymerase sigma factor RpoD 129 0.22 Transcription Phenylalanyl tRNA synthetase beta chain (EC 6.1.1.20) 127 0.21 Translation (tRNA biosynthesis) Succinate dehydrogenase flavoprotein subunit (EC 1.3.99.1) 127 0.21 Krebs cycle Lipid A export ATP binding/permease protein MsbA 125 0.21 Transport (lipid export) Glucosamine fructose