Microbial consumption of zero-valence sulfur in marine benthic habitats.
Zero-valence sulfur (S°) is a central intermediate in the marine sulfur cycle and forms conspicuous accumulations at sediment surfaces, hydrothermal vents and in oxygen minimum zones. Diverse microorganisms can utilize S°, but those consuming S° in the environment are largely unknown. We identified possible key players in S° turnover on native or introduced S° in benthic coastal and deep-sea habitats using the 16S ribosomal RNA approach, (in situ) growth experiments and activity measurements. In all habitats, the epsilonproteobacterial Sulfurimonas/Sulfurovum group accounted for a substantial fraction of the microbial community. Deltaproteobacterial Desulfobulbaceae and Desulfuromonadales were also frequently detected, indicating S° disproportionation and S° respiration under anoxic conditions. Sulfate production from S° particles colonized in situ with Sulfurimonas/Sulfurovum suggested that this group oxidized S°. We also show that the type strain Sulfurimonas denitrificans is able to access cyclooctasulfur (S₈), a metabolic feature not yet demonstrated for sulfur oxidizers. The ability to oxidize S°, in particular S8 , likely facilitates niche partitioning among sulfur oxidizers in habitats with intense microbial sulfur cycling such as sulfidic sediment surfaces. Our results underscore the previously overlooked but central role of Sulfurimonas/Sulfurovum group for conversion of free S° at the seafloor surface.
Max Planck Institute for Marine Microbiology, Bremen, Germany.
Petra
P
Pjevac
Alexey
A
Kamyshny
Stefan
S
Dyksma
Marc
M
Mussmann
D018441:Biofilms; D020564:Deltaproteobacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017753:Ecosystem; D020565:Epsilonproteobacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D019015:Geologic Sediments / Q000737:chemistry; D060086:Hydrothermal Vents; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D013431:Sulfates / Q000378:metabolism; D013455:Sulfur / Q000032:analysis / Q000378:metabolism*
D012336:RNA, Ribosomal, 16S; D013431:Sulfates; D013455:Sulfur