PMID- 34468192 OWN - NLM STAT- MEDLINE DCOM- 20220202 LR - 20220202 IS - 2165-0497 (Electronic) IS - 2165-0497 (Linking) VI - 9 IP - 2 DP - 2021 Oct 31 TI - Conspicuous Smooth and White Egg-Shaped Sulfur Structures on a Deep-Sea Hydrothermal Vent Formed by Sulfide-Oxidizing Bacteria. PG - e0095521 LID - 10.1128/Spectrum.00955-21 [doi] LID - e00955-21 AB - Conspicuous egg-shaped, white, and smooth structures were observed at a hydrothermal vent site in the Guaymas Basin, Gulf of California. The gelatinous structures decomposed within hours after sampling. Scanning electron microscopy (SEM) and light microscopy showed that the structure consisted of filaments of less than 0.1 mum thickness, similar to those observed for "Candidatus Arcobacter sulfidicus." SEM-energy-dispersive X-ray spectroscopy (EDS) showed that the filaments were sulfur rich. According to 16S rRNA gene amplicon and fluorescence in situ hybridization (FISH) analyses, Arcobacter, a sulfide oxidizer that is known to produce filamentous elemental sulfur, was among the dominant species in the structure and was likely responsible for its formation. Arcobacter normally produces woolly snowflake like structures in opposed gradients of sulfide and oxygen. In the laboratory, we observed sulfide consumption in the anoxic zone of the structure, suggesting an anaerobic conversion. The sulfide oxidation and decomposition of the structure in the laboratory may be explained by dissolution of the sulfur filaments by reaction with sulfide under formation of polysulfides. IMPORTANCE At the deep-sea Guaymas Basin hydrothermal vent system, sulfide-rich hydrothermal fluids mix with oxygenated seawater, thereby providing a habitat for microbial sulfur oxidation. Microbial sulfur oxidation in the deep sea involves a variety of organisms and processes and can result in the excretion of elemental sulfur. Here, we report on conspicuous white and smooth gelatinous structures found on hot vents. These strange egg-shaped structures were often observed on previous occasions in the Guaymas Basin, but their composition and formation process were unknown. Our data suggest that the notable and highly ephemeral structure was likely formed by the well-known sulfide-oxidizing Arcobacter. While normally Arcobacter produces loose flocs or woolly layers, here smooth gel-like structures were found. FAU - van Erk, Marit R AU - van Erk MR AUID- ORCID: 0000-0002-7074-3729 AD - Max Planck Institute for Marine Microbiologygrid.419529.2, Bremen, Germany. FAU - Krukenberg, Viola AU - Krukenberg V AD - Montana State University, Bozeman, Montana, USA. FAU - Bomholt Jensen, Pia AU - Bomholt Jensen P AD - Aarhus University, Aarhus, Denmark. FAU - Littmann, Sten AU - Littmann S AD - Max Planck Institute for Marine Microbiologygrid.419529.2, Bremen, Germany. FAU - de Beer, Dirk AU - de Beer D AD - Max Planck Institute for Marine Microbiologygrid.419529.2, Bremen, Germany. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't PT - Research Support, U.S. Gov't, Non-P.H.S. DEP - 20210901 PL - United States TA - Microbiol Spectr JT - Microbiology spectrum JID - 101634614 RN - 0 (RNA, Ribosomal, 16S) RN - 0 (Sulfides) RN - 70FD1KFU70 (Sulfur) SB - IM MH - Anaerobiosis/physiology MH - Arcobacter/*classification/genetics/*metabolism MH - Hydrothermal Vents/*microbiology MH - In Situ Hybridization, Fluorescence MH - Mexico MH - Oceans and Seas MH - Oxidation-Reduction MH - RNA, Ribosomal, 16S/genetics MH - Seawater/chemistry MH - Sulfides/*metabolism MH - Sulfur/*metabolism PMC - PMC8557937 OTO - NOTNLM OT - Arcobacter OT - hydrothermal vent OT - sulfide oxidation OT - sulfur filaments EDAT- 2021/09/02 06:00 MHDA- 2022/02/03 06:00 PMCR- 2021/09/01 CRDT- 2021/09/01 12:16 PHST- 2021/09/02 06:00 [pubmed] PHST- 2022/02/03 06:00 [medline] PHST- 2021/09/01 12:16 [entrez] PHST- 2021/09/01 00:00 [pmc-release] AID - 00955-21 [pii] AID - 10.1128/Spectrum.00955-21 [doi] PST - ppublish SO - Microbiol Spectr. 2021 Oct 31;9(2):e0095521. doi: 10.1128/Spectrum.00955-21. Epub 2021 Sep 1.