Project description:In this study, the effect of nitroprusside on protein expression of the model sulfate reducing bacterial isolate (Desulfovibrio vulgaris Hildenborough) was investigated. Three different experiments were done with different exposure time to nitroprusside (30 min, 1 hour, and 3 hours). In each experiment, the culture was grown in quadruplet of serum bottles containing 40 ml complex medium (Postgate medium B) under anaerobic condition at 30oC. At mid-log growth phase, each of the quadruplet culture was divided into two (20 ml each) and nitroprusside (0.25 mM) was added to one of each bottle while the other bottles were used as controls. After 30 min, 1 hour, and 3 hours of exposure to nitroprusside, the culture (1 ml) was pelleted and used for proteomic analysis.
Project description:Sulfur metabolism in the deep-sea cold seep has been mentioned to have an important contribution to the biogeochemical cycle of sulfur in previous studies. And sulfate reducing bacteria have also been considered to be a dominant microbial population in the deep-sea cold seep and play a crucial role in this process. However, most of sulfate reducing bacteria from cold seep still cannot be purely cultured under laboratory conditions, therefore the actual sulfur metabolism pathways in sulfate reducing bacteria from the deep-sea cold seep have remained unclear. Here, we isolate and pure culture a typical sulfate reducing bacterium Desulfovibrio marinus CS1 from the sediment sample of the deep-sea cold seep in the South China Sea, which provides a probability to understand the sulfur metabolism in the cold seep.
Project description:Bioavailability of electron acceptors is probably the most limiting factor in the restoration of anoxic, contaminated environments. The oxidation of contaminants such as aromatic hydrocarbons, particularly in aquifers, often depends on the reduction of ferric iron or sulphate. We have previously detected a highly active fringe zone beneath a toluene plume at a tar-oil contaminated aquifer in Germany, where a specialized community of contaminant degraders co-dominated by Desulfobulbaceae and Geobacteraceae had established. Although on-site geochemistry links degradation to sulphidogenic processes, dominating catabolic (benzylsuccinate synthase alpha-subunit, bssA) genes detected in situ appeared more related to those of Geobacter spp. Therefore, a stable isotope probing (SIP) incubation of sediment samples with 13C7-toluene and comparative electron acceptor amendment was performed. We introduce pyrosequencing of templates from SIP microcosms as a powerful new strategy in SIP gradient interpretation (Pyro-SIP). Our results reveal the central role of Desulfobulbaceae for sulphidogenic toluene degradation in situ, and affiliate the detected bssA genes to this lineage. This, and the absence of 13C-labelled DNA of Geobacter spp. in SIP gradients preclude their relevance as toluene degraders in situ. In contrast, Betaproteobacteria related to Georgfuchsia spp. became labelled under iron-reducing conditions. Furthermore, secondary toluene degraders belonging to the Peptococcaceae detected in both treatments suggest the possibility of functional redundancy amongst anaerobic toluene degraders on site.