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ResearchEditorial Article OpenOpen Access Access Prokaryotic Biodiversity in Marine versus Terrestrial Ecosystems: Methylobacteria and Research Ethics U. Kutschera* and S. Schauer Institute of Biology, University of Kassel, D-34132 Kassel, Germany

Abstract Prokaryotic microbes (bacteria) are the most numerous organisms on Earth. In marine environments, cyanobacteria of the genus Prochlorococcus and heterotrophic prokaryotes of the family Pelagibacteraceae are of importance, and in terrestrial ecosystems, plant-associated methylobacteria are very abundant. Here, we summarize the discovery and description of a microbe isolated from the common cord moss, Methylobacterium funariae, as described by Schauer and Kutschera (2011). Based on samples of M. funariae which were provided to colleagues as a gift, our isolate was described without our knowledge and permission for a second time, under another name. We discuss this wasteful and duplicative publication of data generated twice from the same bacterial isolate with respect to the ethics for the conduct of research in the biological sciences.

Despite their minute size, bacteria are the most numerous and is likely to be validated in the International Journal of Systematic and diverse forms of life in the world. In marine ecosystems, phototrophic Evolutionary Microbiology (IJSEM)? I am wondering if the earlier cyanobacteria of the genus Prochlorococcus and heterotrophic microbes report (April 2011) will have taxonomic precedence, or whether the of the family Pelagibacteraceae, also known as the ‘SAR11 bacterial report by Hoppe et al. [8] will be the validated name, as they deposited clade’, are among the most abundant prokaryotes [1]. However, despite the type strain in the German Collection of Microorganisms and Cell their proliferation throughout the world’s oceans, the taxonomy of these Cultures (DSMZ), as required by the international nomenclatural important bacteria is still unclear. In terrestrial ecosystems, members of the alpha-proteobacterial genus Methylobacterium are abundant epiphytic microbes that have been isolated from the leaf surfaces of bryophytes, mosses, ferns, and seed plants. Methylobacteria are capable of growing on a variety of one-carbon compounds, such as methanol, which is emitted from the stomatal pores of the leaves. About 40 bacterial species (i.e., defined strains) of these pink-pigmented, Gram- negative prokaryotes have been described so far [2]. In this personal account, we describe a case study of bacterial systematics that sheds light on current problems in publication ethics [3]. In 2003, we isolated methylobacteria from the upper surface of the thallus of the liverwort Marchantia polymorpha. The “primitive” land plants were collected from Bergpark Wilhelmshöhe (Kassel, Germany). Later, we described one of our lab strains, labelled ‘JT1’, as novel species (Methylobacterium marchantiae) [4]. One year before (May 2002), we had isolated another strain (F3.2) from the phylloids of the common cord moss Funaria hygrometrica, collected in the Bot. Garden of the University of Kassel, where Figure 1: Population of sunflower plants (Helianthus annuus , Linnaeus 1753) sunflower plants were raised (Figure 1), and cultivated these microbes in an open field in Germany. The leaves, stems and roots of these and other in the Plant Physiology laboratories of the Institute of Biology. This embryophytes are colonized by prokaryotic microbes, such as methylobacte- isolate was described informally as Methylobacterium funariae in ria. Cells of the species Methylobacterium funariae , as described by Schauer the PhD thesis of the second author [5], and later, supplemented by and Kutschera, 2011, are shown in the Inset (scanning electron micrograph of bacteria attached to a solid surface). additional data, as a new species in a peer-reviewed journal [6]. In his “Validation list no. 145”, Euzéby [7] proposed that our strain F3.2 should be assigned to the taxon Methylobacterium bullatum sp. nov [8], but added the following footnote: “Based on the strain history *Corresponding author: Ulrich Kutschera, PhD, Institute of Biology, University of of the type strain of Methylobacterium bullatum, it appears that Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel, Germany, E-mail: [email protected] strain F3.2 has also been used as the type strain of ‘Methylobacterium Received August 23, 2012; Accepted August 24, 2012; Published August 29, funariae’ (Schauer and Kutschera, 2011)” [6]. In Feb. 2012, we received 2012 a pertinent e-mail from a colleague (D. P. Kelly, University of Warwick, Citation: Kutschera U, Schauer S (2012) Prokaryotic Biodiversity in Marine versus UK; 15th February, 2012): “I have a query about Methylobacterium Terrestrial Ecosystems: Methylobacteria and Research Ethics. J Marine Sci Res Dev 2:e113. doi:10.4172/2155-9910.1000e113 funariae. While making a survey of the 16S rRNA gene accessions of all the published species, I found that strain F3.2 has been described twice Copyright: © 2012 Kutschera U, et al. This is an open-access article distributed with different names M.( funariae and M. bullatum) by separate groups under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the at Kassel. Can you tell me how this happened, and which of the names original author and source are credited.

J Marine Sci Res Dev ISSN:2155-9910 JMSRD an open access journal Volume 2 • Issue 4 • 1000e113 Citation: Kutschera U, Schauer S (2012) Prokaryotic Biodiversity in Marine versus Terrestrial Ecosystems: Methylobacteria and Research Ethics. J Marine Sci Res Dev 2:e113. doi:10.4172/2155-9910.1000e113

Page 2 of 2 rules”. Moreover, a recent report [9] misinterpreted the two-fold clade [1] and land plant-associated methylobacteria [14] are in fact description of our isolate F3.2, and erroneously discussed “two” the dominant heterotrophic prokaryotic microbes in their respective separate bacterial species. However, our unpublished DNA sequence- ecosystems. based phylogenetic trees document that M. funariae and M. bullatum References are identical bacterial species. In this editorial, we elucidate the mysterious two-fold description of our isolate Methylobacterium F3.2 1. Brown MV, Lauro FM, Demaere MZ, Muir L, Wilkins D, et al. (2012) Global biogeography of SAR11 marine bacteria. Mol Syst Biol 8: 595. (Figure 1). 2. Green PN (2005) Methylobacterium In: Bergey’s Manual of Systematic In our first research paper that was published in the year when Bacteriology 567-571. Edited by Brenner DJ, Krieg NR, Garrity GM, Staley JT, we isolated lab strain Methylobacterium F3.2, we characterized the Boone DR, de Vos P, Goodfellow M, Rainey RA, Schleifer KH: Springer-Verlag, unique phenotype of our “Methylobacterium sp. that was isolated New York. from the phylloid” [10]. Moreover, we quantified the ability of 3. Shamoo AE, Resnik DB (2009) Responsible Conduct of Research (2nd edn). Methylobacterium sp.F3.2 to secrete cytokinines, using a Funaria National Science Foundation: Oxford University Press, New York. hygrometrica-protonemata-bioassay. In two subsequent reports 4. Schauer S, Kämpfer P, Wellner S, Spröer C, Kutschera U (2011) [11,12], Methylobacterium sp. F3.2 was further characterized with Methylobacterium marchantiae sp. nov., a pink-pigmented, facultatively methylotrophic bacterium isolated from the thallus of a liverwort. Int J Syst Evol respect to its capability to synthesize and secrete the phytohormone Microbiol 61: 870-876. auxin. Based on these extensive studies, “Methylobacterium sp. isolated from phylloids of F. hygrometrica” [10] was described as M. funariae 5. Schauer S (2009) Biofilmbildung bei Pflanzen-assoziierten Bakterien der Gattung Methylobacterium und molekulargenetisch-physiologische [5,6]. Charakterisierung eines neuen Marchantia-Isolats (Mtb. sp. JT1). Inaugural- Dissertation, Universität Kassel, Kassel. In our article which was published ten years ago [10], we depicted scanning electron micrographs that document the rugged outer 6. Schauer S, Kutschera U (2011) A novel growth-promoting microbe, Methylobacterium funariae sp. nov., isolated from the leaf surface of a common surface of Methylobacterium sp. F3.2 (see Figure 1, Inset). To further moss. Plant Signal Behav 6: 510-515. characterize the fimbriae-like structures on the outer wall layer of 7. Euzéby J (2012) Validation List no. 145. List of new names and new this isolate, we provided samples of Methylobacterium sp. F3.2 to combinations previously effectively, but not validly, published. Int J Syst Evol the microbiology lab of the Institute of Biology, University of Kassel Microbiol 62: 1017-1019. (Principal Investigator: F. Schmidt). However, without our knowledge 8. Hoppe T, Peters K, Schmidt F (2011) Methylobacterium bullatum sp. nov., and permission, our colleagues used our un-described microbial taxon a methylotrophic bacterium isolated from Funaria hygrometrica. Syst Appl to work on a second species description. They were informed that our Microbiol 34: 482-486. isolate had already been named M. funariae by Schauer (2009) [5], and 9. Tani A, Sahin N, Matsuyama Y, Enomoto T, Nishimura N, et al. (2012) High- that a corresponding species description was in preparation. It should throughput identification and screening of novel Methylobacterium species be noted that the first author of this second paper [8] proposed to share using whole-cell MALDI-TOF/MS analysis. PloS One 7: e40784. data, publish them, and give a valid species description in the IJSEM. 10. Hornschuh M, Grotha R, Kutschera U (2002) Epiphytic bacteria associated with We agreed to the proposal of T. Hoppe, but the PI of the microbiology the bryophyte Funaria hygrometrica: Effects of Methylobacterium strains on lab (F. Schmidt) declined our offer (the second “author” on the Hoppe protonema development. Plant Biol 4: 682-687. et al.-article [8] is a technician without academic qualification). 11. Hornschuh M, Grotha R, Kutschera U (2006) Moss-associated methylobacteria as phytosymbionts: an experimental study. Naturwissenschaften 93: 480-486. As a result, two species descriptions were published [6,8], and 12. Kutschera U (2007) Plant-associated methylobacteria as co-evolved although our paper appeared in print first, and Schauer (2009) [5] had phytosymbionts: a hypothesis. Plant Signal Behav 2: 74-78. already described this taxon two years earlier, the name “M. bullatum” 13. Kämpfer P (2010) Certificates of deposit - a key element of the Bacteriological has been accepted by IJSEM [7].We are aware of the fact that, according Code and an indispensable prerequisite for comparative taxonomic research. to the Bacterial Code 1990 Revision, the “date of effective publication Report of a case of falsification and a reply to the letter to the editor by Tindall does not determine priority” (Rules 23b and 27). (2008). Int J Syst Evol Microbiol 60: 475-477. In a recent editorial published in the IJSEM, Kämpfer [13] described 14. Schauer S, Kutschera U (2008) Methylotrophic bacteria on the surfaces of field-grown sunflower plants: a biogeographic perspective. Theory Biosci 127: a case of falsification of ‘Certificates of Deposit’ and reminded the 23-29. readers that the IJSEM is a member of the Committee on Publication Ethics. We feel that the “M. bullatum case” described here is clearly a violation of the ethical standards in biology, since, according to the “Codes and policies for research ethics”, scientists should avoid duplicate publication and not deceive colleagues [3]. We hope that such a wasteful and two-fold description of the same bacterial isolate, provided by the discoverers of this taxon as a gift to colleagues, will not happen again. Finally, we want to point out that methylobacteria are among the most abundant heterotrophic microbes of the above-ground phytosphere (stems, leaves) in terrestrial ecosystems. Moreover, they also inhabit the rhizosphere of all land plants investigated so far [14]. Hence, these microbes may be viewed as ecological counterparts to the marine Pelagibacteraceae, which are likewise members of the alpha- proteobacteria [1,14]. However, more experimental work is required to further corroborate our conclusion that the marine SAR11 bacterial

J Marine Sci Res Dev ISSN:2155-9910 JMSRD an open access journal Volume 2 • Issue 4 • 1000e113