Table S1 (major OTUs) BLAST Genus/ OTU Blast_Identifi- Phylum Class Order Family Sample 1 Sample 2 Sample 3 % Source Ref RDP species IDs cation identity Acidobacteria; Blastocatellia; Bacteria; Acidobacteria; NA 0.093 0.745 2.22 Blastocatellales; -- -- -- Acidobacteria_Gp4 Blastocatellaceae_ denovo1963 NA RB41 Ellin6075 Acidobacteria Acidobacteria; [Chloracidobacteria] Blastocatellia; Bacteria; Acidobacteria; NA 0.467 1.397 0.905 Blastocatellales; -- -- -- Acidobacteria_Gp4 Blastocatellaceae_ denovo1096 NA Bacteria; Actinobacteria; Actinobacteria; Actinobacteria; Acidimicrobiia; sediment Acidimicrobidae; Acidimicrobiales; NA 2.056 0.279 0 97 of an Acidimicrobiales; C111 Acidimicrobiaceae; estuary Acidimicrobineae; Ilumatobacter denovo4002 Acidimicrobiia Actinobacteria Acidimicrobiaceae genus Acidimicrobiales flumins Ilumatobacter (Matsumoto al.,, et 2009) Genus/ OTU_ Blast_Identificatio BLAST % Phylum Class Order Family Sample 1 Sample 2 Sample 3 Source Ref RDP species IDs n iden-tity Bacteria; Actinobacteria; Bacteria; Actinobacteria; subglacial Acidothermales; Actinobacteria; NA NA 0.561 0.838 0.164 97 Lake Acidothermaceae; Actinobacteridae; Sediment denovo223 Acidothermus Actinomycetales cellulosoliticus (Pearse et al.,, et (Pearse 2013) Bacteria; Actinobacteria; cryotubes Actinobacteria; Actinobacteria; at Micrococcales; Actinobacteridae; NA 0.561 2.98 19.079 98 elevation Intrasporangiaceae Actinomycetales; of 21 to ; Janibacter hoylei Micrococcineae; denovo2925 Acidimicrobiia Actinobacteria 41 km Acidimicrobiales Intrasporangiaceae (Shivaji et al., 2009)(Shivaji et Intrasporangiaceae Bacteria; Actinobacteria; Actinobacteria; antarctic Actinobacteria; Micrococcales; sandy Actinobacteridae; NA 1.215 0 0.658 Microbacteriaceae 100 intertidal Actinomycetales; ; Marisediminicola denovo395 sediments Micrococcineae; antarctica al.,(Li 2010) et Microbacteriaceae Microbacteriaceae Genus/ OTU_ Blast_Identificatio BLAST % Phylum Class Order Family Sample1 Sample2 Sample3 Source Ref RDP species IDs n iden-tity Bacteria; Actinobacteria; Actinobacteria; Actinobacteria; pond in Micrococcales; Actinobacteridae; McMurdo NA 2.336 1.304 0.576 Micrococcaceae; 99 Actinomycetales; Dry Valley, Arthrobacter Micrococcineae; Antarctica denovo3122 flavus Microbacteriaceae;unclassified Micrococcaceae (Reddy al., 2000) et _Microbacteriaceae ice tongue Bacteria; Actinobacteria; surface of Actinobacteria; Actinobacteria; the Micrococcales; Actinobacteridae; Hailuogou NA 7.612 1.79 0.509 Nocardioidaceae; 98 Actinomycetales; glacier in Nocardioides Propionibacterineae; Szechwan denovo3556 Acidimicrobiia Actinobacteria glacieisoli Nocardioidaceae; (Liu al., 2015) et Acidimicrobiales Province, Nocardioides PR China Nocardioidaceae Bacteria; Actinobacteria; Actinobacteria; Hailuogou Actinobacteria; Micrococcales; glacier in Actinobacteridae; 1.215 0.372 0.082 Nocardioidaceae; 98 Szechwan Actinomycetales; Nocardioides province, Micrococcineae; denovo3875 Nocardioides szechwanensis PR China (Liu al., 2013) et Micrococcaceae; Arthrobacter Genus/ OTU_ Blast_Identificatio BLAST % Phylum Class Order Family Sample1 Sample2 Sample3 Source Ref RDP species IDs n iden-tity Bacteria; Actinobacteria; Actinobacteria; Actinobacteria; Geodermatophilal Actinobacteridae; NA 1.308 0.559 0.164 es; -- -- -- Actinomycetales; Geodermatophilac Micrococcineae; denovo2123 eae_NA Sporichthyaceae Micrococcaceae Actinobacteria; Bacteria; Actinobacteria; Thermoloephilia; NA 0.093 4.842 0 -- -- -- Actinobacteria; Gaiellales; Rubrobacteridae Gaiellales Gaiellaceae_NA denovo3689 Actinobacteria Thermoleophilia Gaiellaceae Actinobacteria; Bacteria; Actinobacteria; Thermoloephilia; Actinobacteria; NA 2.523 0.652 0 -- -- -- Gaiellales; Rubrobacteridae; Gaiellales; Gaiellaceae_NA Gaiellaceae; Gaiella denovo2010 Genus/ OTU_ Blast_Identificatio BLAST % Phylum Class Order Family Sample1 Sample2 Sample3 Source Ref RDP species IDs n iden-tity Actinobacteria; Bacteria; Actinobacteria; Thermoloephilia; Actinobacteria; NA 0.374 1.304 0 -- -- -- Gaiellales; Rubrobacteridae; Gaiellales; Gaiellales Gaiellaceae_NA Gaiellaceae; Gaiella Gaiellaceae denovo1087 Actinobacteria Thermoleo-philia Actinobacteria; Bacteria; Actinobacteria; Thermoloephilia; Actinobacteria; NA NA 0.093 1.304 0 -- -- -- Gaiellales; Rubrobacteridae; Gaiellales; Gaiellaceae_NA Gaiellaceae; Gaiella denovo1281 Actinobacteria Thermoleophilia Solirubrobacterales Actinobacteria; Thermoloephilia; Bacteria; Actinobacteria; NA NA 0 3.538 0 -- -- -- Solirubrobacterale unclassified_Actinobacteria denovo586 s_NA Genus/ OTU_ Blast_Identificatio BLAST % Phylum Class Order Family Sample1 Sample2 Sample3 Source Ref RDP species IDs n iden-tity Bacteroidetes; Bacteria; Bacteroidetes; Chitinophagia; Sphingobacteriia; NA 0.841 14.432 1.974 Chitinophagales; -- -- -- Sphingobacteriales; Chitinophagaceae_ Chitinophagaceae; denovo2829 NA unclassified_Chitinophagaceae Bacteroidetes; Bacteria; Bacteroidetes; Chitinophagia; Sphingobacteriia; NA 0.561 0.279 1.809 Chitinophagales; -- -- -- Sphingobacteriales; Chitinophagaceae_ Chitinophagaceae; denovo819 [Saprospirae] Bacteroidetes [Saprospirales] NA unclassified_Chitinophagaceae Chitinophagaceae Bacteria; Proteobacteria; Bacteria; Proteobacteria; Betaproteobacteri Betaproteobacteria; 1.176 0.366 0.344 -- -- -- a; Burkholderiales; unclassified_Betaproteobacteri denovo3 Oxalobacteraceae_ a Flavisolibacter NA Genus/ OTU_ Blast_Identificatio BLAST % Phylum Class Order Family Sample1 Sample2 Sample3 Source Ref RDP species IDs n iden-tity Bacteria; Proteobacteria; Deltaproteobacteri 0.197 0.924 0.156 a; -- -- -- Bacteria; unclassified_Bacteria denovo4 Syntrophobacteral es; Sediminibacterium Syntrophaceae_NA [Saprospirae] [Saprospirales] Bacteria; Chitinophagaceae Proteobacteria; Gammaproteobact 0.692 0.796 0.248 -- -- -- Bacteria; unclassified_Bacteria eria; denovo5 Oceanospirillales_ Segetibacter Bacteroidetes NA Bacteroidetes; Sphingobacteriia; Bacteria; Bacteroidetes; Sphingobacteriales Sphingobacteriia; NA 5.701 0 0.247 ; 99 soil Sphingobacteriales; Sphingobacteriace Sphingobacteriaceae; denovo3996 ae; Pedobacter Pedobacter Sphingobacteriia Sphingobacteriales Sphingobacteriaceae ruber (Margesin (Margesin & Zhang 2013) Genus/ OTU_ Blast_Identificatio BLAST % Phylum Class Order Family Sample1 Sample2 Sample3 Source Ref RDP species IDs n iden-tity Firmicutes; Bacilli; Bacteria; Acidobacteria; NA NA NA 0.935 0.559 0.247 -- -- -- Bacillales_NA Acidobacteria_Gp16; Gp16 Ellin6529 Chloroflexi denovo1831 Cyanobacteria; Nostocales; Bacteria; NA 0 0.093 2.138 Nostocaceae; 98 -- -- Cyanobacteria/Chloroplast; Anabaena Cyanobacteria; Family I; GpI denovo872 cylindrica Nostocales Nostocaceae Cyanobacteria Nostocophycideae Cyanobacteria; Nostocales; Bacteria; 0 0 15.049 Nostocaceae; 99 -- -- Cyanobacteria/Chloroplast; Nostoc Nostoc Cyanobacteria; Family I; GpI denovo741 punctiforme Genus/ OTU_ Blast_Identificatio BLAST % Phylum Class Order Family Sample1 Sample2 Sample3 Source Ref RDP species IDs n iden-tity Antarctica Cyanobacteria; : James Oscillatoriophycide Ross Bacteria; ae; Oscillatoriales; Island, 3.271 2.235 0 100 Cyanobacteria/Chloroplast; Phormidiaceae; Lake Cyanobacteria denovo310 Phormidium Phormidiu Phormidium Oscillatoriales Cyanobacteria Phormidiaceae autumnale m, Oscillatoriophycideae sediment (Strunecký et al., 2012) Gemmatimonadet es; NA NA 0 1.397 0 -- -- -- Bacteria; unclassified_Bacteria Gemmatimonadale N1423WL s_NA denovo1054 Gemmatimonadetes Gemmatimonadetes Proteobacteria; Alphaproteobacter Bacteria; Proteobacteria; ia; Alphaproteobacteria; antarctic 1.589 0.186 0.329 Caulobacterales; 100 Caulobacterales; NA soils Caulobacteraceae; Caulobacteraceae; denovo432 Brevundimonas Brevundimonas Proteobacteria Caulobacterales Caulobacteraceae Alphaproteobacteria vesicularis (Matvieieva et al., 2017) et (Matvieieva Genus/ OTU_ Blast_Identificatio BLAST % Phylum Class Order Family Sample1 Sample2 Sample3 Source Ref RDP species IDs n iden-tity Proteobacteria; Bacteria; Proteobacteria; Alphaproteobacter Alphaproteobacteria; ia; lagoon Rhodobacterales; NA 0.748 0 0.576 Rhodobacterales; 100 sediments Rhodobacteraceae; Rhodobacteraceae unclassified_Rhodobacteraceae denovo2067 ; Rhodobacter Rhodobacterales Rhodobacteraceae sediminis (Subhash al., 2017) et Proteobacteria; Alphaproteobacter Bacteria; Proteobacteria; ia; Alphaproteobacteria; Sphingomonadales freshewat Sphingomonadales; NA 2.804 0.745 0.987 ; 99 er, Sphingomonadaceae; Sphingomonadace sediments unclassified_Sphingomonadace denovo1395 (Li et al.,(Li 2012) et Proteobacteria ae; ae Alphaproteobacteria Novosphingobium stygium Bacteria; Proteobacteria; Sphingomonadales Alphaproteobacter Bacteria; Proteobacteria; Sphingomonadaceae ia; Alphaproteobacteria; 7.196 0.931 1.316 Sphingomonadales 100 road soil Sphingomonadales; ; Sphingomonadaceae; denovo3743 Kaistobacter Sphingomonadace Sphingomonas (Du al.,, et 2015) ae; Sphingomonas flava Genus/ OTU_ Blast_Identificatio BLAST % Phylum Class Order Family Sample1 Sample2 Sample3 Source Ref RDP species IDs n iden-tity Bacteria; Proteobacteria; Alphaproteobacter Bacteria; Actinobacteria; ia; 1.055 0.239 0.371 -- -- -- Actinobacteria; Sphingomonadales denovo6 unclassified_Actinobacteria ; Novosphingobium Sphingomonadace ae_NA Bacteria; Proteobacteria; Sphingomonadales Alphaproteobacteria Alphaproteobacter Bacteria; Proteobacteria; Sphingomonadaceae ia; Alphaproteobacteria; 0.093 0.093 1.809 Sphingomonadales 99 seawater Sphingomonadales; ; Sphingomonadaceae; denovo3521 Sphingomonas Proteobacteria Sphingomonadace Sphingomonas