Project description:Desulfurella amilsii is an acidotolerant sulfur-reducing bacterium isolated from sediments of an acidic river. It can grow in a broad range of pH and can obtain energy via respiring elemental sulfur or thiosulfate, as well as by disproportionating elemental sulfur. Its genome encodes the enzyme sulfur reductase, and several rhodanese-like proteins, possibly playing a role in sulfur respiration and disproportionation. Thiosulfate reductase and dissimilatory sulfite reductase are encoded and might play a role during the respiration of thiosulfate. The involvement of these enzymes in the reductive routes of sulfur metabolism is not yet clearly understood. Desulfurella amilsii was used in this study to combine strategies for sulfur metabolism research on the protein level to shed some light on the pathways involved in the metabolism of this microorganism.
Project description:Since both endogenous synthesis in tumor cells and bacterial sulfur reduction activities are sources of H2S in colon cancer microenvironment, in addition to using CBS -/+ mice, we also investigated the roles of reducing H2S through adopting a sulfur amino acid restriction diet (SARD) (0.15% methionine and 0% cystine) on immunotherapy (anti-PD-L1) of colon cancer. Tumor bulk sequencing was performed in cecum orthotopic CT26 tumors collected from IgG and anti-PD-L1 treated mice both receiving normal diet and SARD.
Project description:Little is known about cell responses and survival in the presence if reducing agents that could change the redox state of living organisms potentially conferring a negative effect on major metabolic pathways and respiration. As many reducing reagents, in particular sulfur-containing compounds, are widely used as food preservatives, we decided to study effects of sublethal concentrations of reducing reagents on bacterial adaptation. The aim of this study was to analyse and compare the transcriptome profils of untreated and sulfite-treated Escherichia coli cells obtained by employing microarray analysis.
Project description:Competition among nitrate reducing bacteria (NRB) and sulfate reducing bacteria (SRB) for resources in anoxic environments is generally thought to be governed largely by thermodynamics. It is now recognized that intermediates of nitrogen and sulfur cycling (e.g., hydrogen sulfide, nitrite, etc.) can also directly impact NRB and SRB activities in freshwater, wastewater and sediment, and therefore may play important roles in competitive interactions. Here, using Intrasporangium calvum C5 as a model NRB, we performed comparative transcriptomic and metabolomic analyses to demonstrate that the reduced sulfur compounds cysteine and sulfide differentially inhibit respiratory growth on nitrate, and that inhibition by each can be selectively relieved by a specific carbon source. These findings provide mechanistic insights into the interplay and stratification of NRBs and SRBs in diverse environments.
