Microbiota of sulfur-rich environments has been extensively studied due to the biotechnological potential of sulfur bacteria, or as a model of ancient life. Cold terrestrial sulfur springs are less studied compared to sulfur-oxidizing microbiota of hydrothermal vents, volcanic environments, or soda lakes. Despite that, several studies suggested that sulfur springs harbor diverse microbial communities because of the unique geochemical conditions of upwelling waters. In this study, the microbiota of five terrestrial sulfur springs was examined using a 16 S rRNA gene sequencing. The clear dominance of the Proteobacteria and Campylobacterota phyla of cold sulfur springs microbiota was observed. Contrary to that, the microbiota of the hot sulfur spring was dominated by the Aquificota and Firmicutes phylum respectively. Sulfur-oxidizing genera constituted a dominant part of the microbial populations with the Thiothrix and Sulfurovum genera identified as the core microbiota of cold sulfur terrestrial springs in Slovakia. Additionally, the study emphasizes that sulfur springs in Slovakia support unique, poorly characterized bacterial communities of sulfur-oxidizing bacteria.

Department of Microbiology Institute of Biology and Ecology Faculty of Science Pavol Jozef Safarik University in Kosice Srobarova 2 Kosice 041 54 Slovakia

Institute of Animal Physiology Centre of Biosciences Slovak Academy of Sciences Soltesovej 4 6 Kosice 040 01 Slovakia

Laboratory of Anaerobic Microbiology Institute of Animal Physiology and Genetics Czech Academy of Sciences Videnska Prague 1083 14220 Czech Republic

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Xia FF, Su Y, Wei XM, He YH, Wu ZC, Ghulam A, He R. Diversity and activity of sulphur-oxidizing bacteria and sulphate-reducing bacteria in landfill cover soils. Lett Appl Microbiol. 2014;59(1):26–34. doi: 10.1111/lam.12240. PubMed DOI

Nagar S, Talwar C, Motelica-Heino M, Richnow HH, Shakarad M, Lal R, Negi RK. Microbial Ecology of Sulfur Biogeochemical Cycling at a Mesothermal Hot Spring atop Northern Himalayas, India. Front Microbiol. 2022;13:848010. doi: 10.3389/fmicb.2022.848010. PubMed DOI PMC

Douglas S, Douglas DD. Structural and geomicrobiological characteristics of a Microbial Community from a Cold Sulfide Spring. Geomicrobiol J. 2001;18(4):401–22. doi: 10.1080/014904501753210567. DOI

Camacho A. Sulfur Bactria. In: Likens GE, editor. Encyclopedia of Inland Waters. Oxford, New York: Elsevier Academic Press; 2010. pp. 261–78.

Purcell AM, Mikucki JA, Achberger AM, Alekhina IA, Barbante C, Christner BC, Ghosh D, Michaud AB, Mitchell AC, Priscu JC, Scherer R, Skidmore ML, Vick-Majors TJ, WISSARD Science Team Microbial sulfur transformations in sediments from Subglacial Lake Whillans. Front Microbiol. 2014;5:594. doi: 10.3389/fmicb.2014.00594. PubMed DOI PMC

Winogradsky S. Bietrage zur Morphologie und Physiologie de Bacterien. Zur Morphologie und Physiologie der Schwfelbacterien: Zur Morphologie und Physiologie der Schwefelbacterien. Heft 1. 1888.

Yang J, Jiang H, Dong H, Wu G, Hou W, Zhao W, Sun Y, Lai Z. Abundance and diversity of sulfur-oxidizing Bacteria along a salinity gradient in four Qinghai-Tibetan Lakes, China. Geomicrobiol J. 2013;30(9):851–60. doi: 10.1080/01490451.2013.790921. DOI

Trivedi CB, Stamps BW, Lau GE, Grasby SE, Templeton AS, Spear JR. Microbial metabolic redundancy is a key mechanism in a Sulfur-Rich glacial ecosystem. mSystems. 2020;5:e00504–20. doi: 10.1128/mSystems.00504-20. PubMed DOI PMC

Lau MCY, Kieft TL, Kuloyo O, Linage-Alvarez B, van Heerden E, Lindsay MR, Magnabosco C. An oligotrophic deep-subsurface community dependent on syntrophy is dominated by sulfur-driven autotrophic denitrifiers. PNAS. 2016;113(49):E7927–36. doi: 10.1073/pnas.1612244113. PubMed DOI PMC

Bell E, Lamminmäki T, Alneberg J, Andersson AF, Qian C, Xiong W, Hettich RL, Frutschi M, Bernier-Latmani R. Active sulfur cycling in the terrestrial deep subsurface. ISME J. 2020;14:1260–72. doi: 10.1038/s41396-020-0602-x. PubMed DOI PMC

Jones DS, Albrecht HL, Dawson KS, Schaperdoth I, Freeman KH, Pi Y, Pearson A, Macalady JL. Community genomic analysis of an extremely acidophilic sulfur-oxidizing biofilm. ISME J. 2012;6:158–70. doi: 10.1038/ismej.2011.75. PubMed DOI PMC

D’Auria G, Artacho A, Rojas RA, Bautista JS, Méndez R, Gamboa MT, Gamboa JR, Gómez-Cruz R. Metagenomics of bacterial diversity in Villa Luz caves with Sulfur Water Springs. Genes. 2018;9(1):55. doi: 10.3390/genes9010055. PubMed DOI PMC

Meier DV, Pjevac P, Bach W, Hourdez S, Girguis PR, Vidoudez C, Amann R, Meyerdierks A. Niche partitioning of diverse sulfur-oxidizing bacteria at hydrothermal vents. ISME J. 2017;11:1545–58. doi: 10.1038/ismej.2017.37. PubMed DOI PMC

Dede B, Hansen CT, Neuholz R, Schnetger B, Kleint C, Walker S, Bach W, Amann R, Meyerdierks A. Niche differentiation of sulfur-oxidizing bacteria (SUP05) in submarine hydrothermal plumes. ISME J. 2022;16:1479–90. doi: 10.1038/s41396-022-01195-x. PubMed DOI PMC

Klatt JM, Meyer S, Häusler S, Macalady JL, De Beer D, Polerecky L. Structure and function of natural sulphide-oxidizing microbial mats under dynamic input of light and chemical energy. ISME J. 2016;10:921–33. doi: 10.1038/ismej.2015.167. PubMed DOI PMC

Himmler T, Smrzka D, Zwicker J, Kasten S, Shapiro RS, Bohrmann G, Peckamn J. Stromatolites below the photic zone in the northern Arabian Sea formed by calcifying chemotrophic microbial mats. Geology. 2018;46(4):339–42. doi: 10.1130/G39890.1. DOI

Tournova TP, Slobodova NV, Bumazhkin BK, Kolganova TV, Muyzer G, Sorokin DY. Analysis of community composition of sulfur-oxidizing bacteria in hypersaline and soda lakes using soxB as a functional molecular marker. FEMS Microbiol Ecol. 2013;84(2):280–9. doi: 10.1111/1574-6941.12056. PubMed DOI

Kubo K, Knittel K, Amann R, Fukui M, Matsuura K. Sulfur-metabolizing bacterial populations in microbial mats of the Nakabusa hot spring, Japan. Syst Appl Microbiol. 2011;34(4):293–302. doi: 10.1016/j.syapm.2010.12.002. PubMed DOI

Huang Q, Jiang H, Briggs BR, Wang S, Hou W, Li G, Wu G, Solis R, Arcilla CA, Abrajano T, Dong H. Archaeal and bacterial diversity in acidic to circumneutral hot springs in the Philippines. FEMS Microbiol Ecol. 2013;85(3):452–64. doi: 10.1111/1574-6941.12134. PubMed DOI

Sattley WM, Madigan MT. Isolation, characterization, and Ecology of Cold-Active, chemolithotrophic, sulfur-oxidizing Bacteria from perennially ice-covered Lake Fryxell, Antarctica. Appl and Environ Microbiol. 2006;72(8):5562–8. doi: 10.1128/AEM.00702-06. PubMed DOI PMC

Hügler M, Gärtner A, Imhoff JF. Functional genes as markers for sulfur cycling and CO2 fixation in microbial communities of hydrothermal vents of the Logatchev field. FEMS Microbiol Ecol. 2010;73(3):526–37. doi: 10.1111/j.1574-6941.2010.00919.x. PubMed DOI

Vavourakis CD, Mehrshad M, Balkema C, van Hall R, Andrei AS, Ghai R, Sorokin DY, Muyzer G. Metagenomes and metatranscriptomes shed new light on the microbial-mediated sulfur cycle in a siberian soda lake. BMC Biol. 2019;17(1):69. doi: 10.1186/s12915-019-0688-7. PubMed DOI PMC

Kriš J, Marton J, Skultétyová I. Mineral and geothermal waters of Slovakia. GeoJournal. 1995;35:431–42. doi: 10.1007/BF00824353. DOI

Cuka P, Rachwal T. Economic, touristic and therapeutic potential of natural water springs in Slovakia. Surveying Geol Min Ecol Manage Int Multidisciplinary Sci GeoConference: SGEM Albena Bulgaria. 2013;2:89–96. doi: 10.5593/SGEM2013/BE5.V2/S21.012. DOI

Bodiš D, Kordik J, Slaninka I, Malík P, Liščák P, Panák D, Božíková J. Mineral waters in Slovakia — evaluation of chemical composition stability using both historical records and the most recent data. J Geochem Explor. 2010;107(3):382–90. doi: 10.1016/j.gexplo.2010.06.009. DOI

Hók J, Šujan M, Šipka F. Tectonic division of the western Carpathians: an overview and a new approach. Acta Geol Slovaca. 2014;6:135–43.

Klago M. New sources of mineral water at the Gánovce locality (Eastern Slovakia). Nové zdroje minerálnej vody v Gánovciach (in Slovak) Mineralia Slovac. 1980;12:541–56.

Marcin D, Benková K. Regional Hydrogeological characteristics of Mineral Water Aquifers in Slovakia. Slovak Geol Mag. 2016;16(2):5–26.

Soták J, Pulišová Z, Plašienka D, Šimonová V. Stratigraphic and tectonic control of deep-water scarp accumulation in Paleogene synorogenic basins: a case study of the Súľov Conglomerates (Middle Váh Valley, Western Carpathians) Geol Carpath. 2017;68(5):403–18. doi: 10.1515/geoca-2017-0027. DOI

Hanajík P, Zvarík M, Fritze H, Šimkovic I, Kanka R. Composition of microbial PLFAs and correlations with topsoil characteristics in the rare active travertine spring-fed fen. Ekol Bratisl. 2016;35(4):295–308. doi: 10.1515/eko-2016-0024. DOI

Hájková P, Jamrichová E, Šolcová A, Frodlová J, Petr L, Dítě D, Hájek M, Horsák M. Can relict-rich communities be of an anthropogenic origin? Palaeoecological insight into conservation strategy for endangered Carpathian travertine fens. Quat Sci Rev. 2020;234:106241. doi: 10.1016/j.quascirev.2020.106241. DOI

Vitovič L, Minár J, Pánek T. Morphotectonic configuration of the Podtatranská Kotlina Basin and its relationship to the origin of the western Carpathians. Geomorphology. 2021;394:107963. doi: 10.1016/j.geomorph.2021.107963. DOI

Meziti A, Nikouli E, Hatt JK, Konstantinidis KT, Kormas KA. Time series metagenomic sampling of the Thermopyles, Greece, geothermal springs reveals stable microbial communities dominated by novel sulfur-oxidizing chemoautotrophs. Environ Microbiol. 2020;23(7):3710–26. doi: 10.1111/1462-2920.15373. PubMed DOI

Roy C, Rameez MJ, Haldar PK, Peketi A, Mondal N, Bakshi U, Mapder T, Pyne P, Fernandes S, Bhattacharya S, Roy R, Mandal S, O’Neill WK, Mazumdar A, Mukhopadyay SK, Mukherjee A, Chakraborty R, Hallsworth JE, Ghosh W. Microbiome and ecology of a hot spring-microbialite system on the Trans-Himalayan Plateau. Sci Rep. 2020;10(1):5917. doi: 10.1038/s41598-020-62797-z. PubMed DOI PMC

Choure K, Parsai S, Kotoky R, Srivastava A, Tilwari A, Rai PK, Sharma A, Pandey P. Comparative metagenomic analysis of two Alkaline Hot Springs of Madhya Pradesh, India and deciphering the Extremophiles for Industrial enzymes. Front Genet. 2021;12:643423. doi: 10.3389/fgene.2021.643423. PubMed DOI PMC

Pedron R, Esposito A, Cozza W, Paolazzi M, Cristofolini M, Segata N, Jousson O. Microbiome characterization of alpine water springs for human consumption reveals site- and usage-specific microbial signatures. Front Microbiol. 2022;13:946460. doi: 10.3389/fmicb.2022.946460. PubMed DOI PMC

Rupasinghe R, Amarasena S, Wickramarathna S, Biggs PJ, Chandrajith R, Wickramasinghe S. Microbial diversity and ecology of geothermal springs in the high-grade metamorphic terrain of Sri Lanka. Environ Adv. 2022;7:100166. doi: 10.1016/j.envadv.2022.100166. DOI

Reigstad LJ, Jorgensen SL, Lauritzen SE, Schleper C, Urich T. Sulfur-oxidizing Chemolithotrophic Proteobacteria dominate the Microbiota in High Arctic Thermal Springs on Svalbard. Astrobiology. 2011;11(7):665–78. doi: 10.1089/ast.2010.0551. PubMed DOI

Elshahed MS, Senko JM, Najjar FZ, Kenton SM, Roe BA, Dewers TA, Spear JR, Krumholz LR. Bacterial diversity and Sulfur Cycling in a Mesophilic Sulfide-Rich Spring. Appl Environ Microbiol. 2003;69(9):5609–21. doi: 10.1128/AEM.69.9.5609-5621.2003. PubMed DOI PMC

Deiner K, Walser JC, Mächler E, Altermatt F. Choice of capture and extraction methods affect detection of freshwater biodiversity from environmental DNA. Biol Conserv. 2015;183:53–63. doi: 10.1016/j.biocon.2014.11.018. DOI

Cruaud P, Vigneron A, Lucchetti-Miganeh C, Ciron PE, Godfroy A, Cambon-Bonavita MA. Influence of DNA extraction method, 16S rRNA targeted hypervariable regions, and Sample Origin on Microbial Diversity detected by 454 pyrosequencing in Marine Chemosynthetic Ecosystems. Appl Environ Microbiol. 2014;80(15):4626–39. doi: 10.1128/AEM.00592-14. PubMed DOI PMC

Terrat S, Christen R, Dequiedt S, Lelièvre M, Nowak V, Regnier T, Bachar D, Plassart P, Wincker P, Jolivet C, Bispo A, Lemanceau P, Maron PA, Mougel C, Ranjard L. Molecular biomass and MetaTaxogenomic assessment of soil microbial communities as influenced by soil DNA extraction procedure. Microb Biotech. 2011;5(1):135–41. doi: 10.1111/j.1751-7915.2011.00307.x. PubMed DOI PMC

Nosalova L, Piknova M, Bonova K, Pristas P. Deep Subsurface Hypersaline Environment as a source of Novel Species of Halophilic Sulfur-Oxidizing Bacteria. Microorganisms. 2022;10(5):995. doi: 10.3390/microorganisms10050995. PubMed DOI PMC

Nosalova L, Fecskeova LK, Piknova M, Bonova K, Pristas P. Unique populations of sulfur-oxidizing Bacteria in Natural Cold Sulfur Springs in Slovakia. Geomicrobiol J. 2023;40(4):315–24. doi: 10.1080/01490451.2023.2167021. DOI

Nosalova L, Kiskova J, Fecskeova LK, Piknova M, Pristas P. Bacterial Community structure of two Cold Sulfur Springs in Slovakia (Central Europe) Curr Microbiol. 2023;80(5):145. doi: 10.1007/s00284-023-03251-x. PubMed DOI

Pospiech A, Neumann B. A versatile quick-prep of genomic DNA from Gram-positive bacteria. Trends Genet. 1995;11(6):217–8. doi: 10.1016/s0168-9525(00)89052-6. PubMed DOI

Fliergerová K, Tapio I, Bonin A, Mrazek J, Callegari ML, Bani P, Bayat A, Vilkki J, Kopečný J, Shingfield KJ, Boyer F, Coissac E, Taberlet P, Wallace RJ. Effect of DNA extraction and sample preservation method on rumen bacterial population. Anaerobe. 2014;29:80–4. doi: 10.1016/j.anaerobe.2013.09.015. PubMed DOI

Milani C, Hevia A, Foroni E, Duranti S, Turroni F, Lugli GA, Sanchez B, Martín R, Gueimonde M, van Sinderen D, Margolles A, Ventura M. Assessing the fecal microbiota: an optimized Ion Torrent 16S rRNA gene-based analysis protocol. PLoS ONE. 2013;8(7):e68739. doi: 10.1371/journal.pone.0068739. PubMed DOI PMC

Mekadim C, Skalnikova HK, Cizkova J, Cizkova V, Palanova A, Horak V, Mrazek J. Dysbiosis of skin microbiome and gut microbiome in melanoma progression. BMC Microbiol. 2022;22(1):63. doi: 10.1186/s12866-022-02458-5. PubMed DOI PMC

Boylen E, Rideout JR, Dillon MR, Bokulich NA, Abnet CC, Al-Ghalith GA, Alexander H, Alm EJ, Arumugam M, Asnicar F, Bai Y, Bisanz JE, Bittinger K, Brejnrod A, Brislawn C, et al. Reproducible, interactive, scalable and extensible microbiome data science using QIIME 2. Nat Biotechnol. 2019;37(8):852–7. doi: 10.1038/s41587-019-0209-9. PubMed DOI PMC

Callahan BJ, McMurdie PJ, Rosen MJ, Han AW, Johnson AJA, Holmes SP. DADA2: high-resolution sample inference from Illumina amplicon data. Nat Methods. 2016;13(7):581–3. doi: 10.1038/nmeth.3869. PubMed DOI PMC

Katoh K, Misawa K, Kuma K, Miyata T. MAFFT: a novel method for rapid multiple sequence alignment based on fast Fourier transform. Nucleic Acids Res. 2002;30(14):3059–66. doi: 10.1093/nar/gkf436. PubMed DOI PMC

Price MN, Dehal PS, Arkin AP. FastTree 2 – approximately maximum-likelihood trees for large alignments. PLoS ONE. 2010;5(3):e9490. doi: 10.1371/journal.pone.0009490. PubMed DOI PMC

Rognes T, Flouri T, Nichols B, Quince C, Mahé F. VSEARCH: a versatile open source tool for metagenomics. PeerJ. 2016;4:e2584. doi: 10.7717/peerj.2584. PubMed DOI PMC

Shannon C. A mathematical theory of communication. Bell Syst Tech J. 1948;27:379–423. doi: 10.1002/j.1538-7305.1948.tb01338.x. DOI

Simpson EH. Measurement of diversity. Nature. 1949;163:688. doi: 10.1038/163688a0. DOI

Pielou EC. The measurement of diversity in different types of biological collections. J Theor Biol. 1996;13:131–44. doi: 10.1016/0022-5193(66)90013-0. DOI

Wickham H. ggplot2: elegant graphics for data analysis. New York, USA: Springer-Verlag; 2016.

Bisanz JE. qiime2R: importing QIIME2 artifacts and associated data into R sessions. 2018. https://github.com/jbisanz/qiime2R (unpublished).

RStudio: Integrated Development for R. RStudio Team, RStudio, Boston MA. 2020. http://www.rstudio.com/.

Lozupone CA, Hamady M, Kelley ST, Knight R. Quantitative and qualitative beta diversity measures lead to different insights into factors that structure microbial communities. Appl Environ Microbiol. 2007;73(5):1576–85. doi: 10.1128/AEM.01996-06. PubMed DOI PMC

Hammer O, Harper DAT, Ryan PD. PAST: Paleontological Statistics Software Package for Education and Data Analysis. Paleontol Electron. 2001;4(1):1–9.

Povinec PP, Franko O, Šivo A, Richtáriková M, Breier R, Aggarwal PK, Araguás-Araguás L. Spatial radiocarbon and stable carbon isotope variability of mineral and thermal waters in Slovakia. Radiocarbon. 2010;52(3):1056–67. doi: 10.1017/S0033822200046130. DOI

Michalko J. Stable isotopes of hydrogen, oxygen and sulphur in the waters of Slovakia. Slovak Geol Mag. 1999;5(1–2):63–7.

Chaudhary A, Haack SK, Duris JW, Marsh TL. Bacterial and archaeal phylogenetic diversity of a cold sulfur-rich spring on the shoreline of Lake Erie, Michigan. Appl Environ Microbiol. 2009;75:5025–36. doi: 10.1128/AEM.00112-09. PubMed DOI PMC

Sayeh R, Birrien JL, Alain K, Barbier G, Hamdi M, Prieur D. Microbial diversity in tunisian geothermal springs as detected by molecular and culture-based approaches. Extremophiles. 2010;14(6):501–14. doi: 10.1007/s00792-010-0327-2. PubMed DOI

Saghatelyan A, Margaryan A, Panosyan H, Birkeland NK. Microbial Diversity of Terrestrial Geothermal Springs in Armenia and Nagorno-Karabakh: a review. Microorganisms. 2021;9(7):1473. doi: 10.3390/microorganisms9071473. PubMed DOI PMC

van der Aa M. Classification of mineral water types and comparison with drinking water standards. Environ Geol. 2003;44:554–63. doi: 10.1007/s00254-003-0791-4. DOI

Gulecal-Pektas Y, Temel M. A window to the subsurface: microbial diversity in hot springs of a sulfidic cave (Kaklik, Turkey) Geomicrobiol J. 2016;34(4):374–84. doi: 10.1080/01490451.2016.1204374. DOI

Wright KE, Williamson C, Grasby SE, Spear JR, Templeton AS. Metagenomic evidence for sulfur lithotrophy by Epsilonproteobacteria as the major energy source for primary productivity in a sub-aerial arctic glacial deposit, Borup Fiord Pass. Front Mcirobiol. 2013;4:63. doi: 10.3389/fmicb.2013.00063. PubMed DOI PMC

Hamilton TL, Jones DS, Schaperdoth I, Macalady JL. Metagenomic insights into S(0) precipitation in a terrestrial subsurface lithoautotrophic ecosystem. Front Microbiol. 2015;5:756. doi: 10.3389/fmicb.2014.00756. PubMed DOI PMC

Huang L, Bae HS, Young C, Pain AJ, Martin JB, Ogram A. Campylobacterota dominate the microbial communities in a tropical karst subterranean estuary, with implications for cycling and export of nitrogen to coastal waters. Environ Microbiol. 2021;23(11):6749–63. doi: 10.1111/1462-2920.15746. PubMed DOI

Campbell BJ, Engel AS, Porter ML, Takai K. The versatile ε-proteobacteria: key players in sulphidic habitats. Nat Rev. 2006;4(6):458–68. doi: 10.1038/nrmicro1414. PubMed DOI

Perreault NN, Greer CW, Andersen DT, Tillie S, Lacrampe-Couloume G, Lollar BS, Whyte LG. Heterotrophic and autotrophic microbial populations in Cold Perennial Springs of the high Arctic. Appl Environ Microbiol. 2008;74(22):6898–907. doi: 10.1128/AEM.00359-08. PubMed DOI PMC

Sharma N, Kumar J, Abedin MM, Sahoo D, Pandey A, Rai AK, Singh SP. Metagenomics revealing molecular profiling of community structure and metabolic pathways in natural hot springs of the Sikkim Himalaya. BMC Microbiol. 2020;20(1):246. doi: 10.1186/s12866-020-01923-3. PubMed DOI PMC

Perreault NN, Andersen DT, Pollard WH, Greer CW, Whyte LG. Characterization of the prokaryotic diversity in cold saline Perennial Springs of the Canadian High Arctic. Appl Environ Microbiol. 2007;73(5):1532–43. doi: 10.1128/AEM.01729-06. PubMed DOI PMC

Magnuson E, Mykytczuk NCS, Pellerin A, Goordial J, Twine SM, Wing B, Foote SJ, Fulton K, Whyte LG. Thiomicrorhabdus streamers and sulfur cycling in perennial hypersaline cold springs in the canadian high Arctic. Environ Microbiol. 2021;23(7):3384–400. doi: 10.1111/1462-2920.14916. PubMed DOI

Sadeepa D, Sirisena K, Manage PM. Diversity of microbial communities in hot springs of Sri Lanka as revealed by 16S rRNA gene high-throughput sequencing analysis. Gene. 2022;812:146103. doi: 10.1016/j.gene.2021.146103. PubMed DOI

Garrity GM, Bell JA, Lilburn T. Thiotrichales ord. nov. In: Brenner DJ, Krieg NR, Staley JT, Garrity GM, Boone DR, Vos P, Goodfellow M, Rainey FA, Schleifer KH, editors. Bergey’s Manual of systematic bacteriology. Boston, MA: Springer; 2005. pp. 131–210.

Headd B, Engel AS. Evidence for niche partitioning revealed by the distribution of sulfur oxidation genes collected from areas of a terrestrial sulfidic spring with differing geochemical conditions. Appl Environ Microbiol. 2013;79(4):1171–82. doi: 10.1128/AEM.02812-12. PubMed DOI PMC

Headd B, Engel AS. Biogeographic congruency among bacterial communities from terrestrial sulfidic springs. Front Microbiol. 2014;5:473. doi: 10.3389/fmicb.2014.00473. PubMed DOI PMC

Mori K, Suzuki K. Thiofaba tepidiphila gen. nov., sp. nov., a novel obligately chemolithoautotrophic, sulfur-oxidizing bacterium of the Gammaproteobacteria isolated from a hot spring. Int J Syst Evol Microbiol. 2008;58(Pt 8):1885–91. doi: 10.1099/ijs.0.65754-0. PubMed DOI

Ito T, Sugita K, Yumoto I, Nadasaka Y, Okabe S. Thiovirga sulfuroxydans gen. nov., sp. nov., a chemolithoautotrophic sulfur-oxidizing bacterium isolated from a microaerobic waste-water biofilm. Int J Syst Evol Microbiol. 2005;55(Pt 3):1059–64. doi: 10.1099/ijs.0.63467-0. PubMed DOI

Zhao L, Shao H, Zhang L, Panno SV, Kelly WR, Lin TY, Liu WT, Flynn TM, Berger P. Impact of salinity origin on microbial communities in saline springs within the Illinois Basin, USA. Environ Microbiol. 2022;24(12):6112–27. doi: 10.1111/1462-2920.16241. PubMed DOI PMC

Macalady JL, Dattagupta S, Schaperdoth I, Jones DS, Druschel GK, Eastman D. Niche differentiation among sulfur-oxidizing bacterial populations in cave waters. ISME J. 2008;2(6):590–601. doi: 10.1038/ismej.2008.25. PubMed DOI

Patwardhan S, Foustoukos DI, Giovannelli D, Yücel M, Vetriani C. Ecological succession of Sulfur-Oxidizing Epsilon- and Gammaproteobacteria during colonization of a Shallow-Water Gas Vent. Front Microbiol. 2018;9:2970. doi: 10.3389/fmicb.2018.02970. PubMed DOI PMC

Gupta P, Manjula A, Rajendhran J, Gunasekaran P, Vakhlu J. Comparison of metagenomic DNA extraction methods for soil sediments of high elevation Puga hot spring in Ladakh, India to explore bacterial diversity. Geomicrobiol J. 2017;34(4):289–99. doi: 10.1080/01490451.2015.1128995. DOI