Project description:Four stable and robust TCE-dechlorinating microbial communities were enriched from TCE-contaminated groundwater under four different conditions exploring two parameters, high and low methanogenic activity (Meth and NoMeth), with and without vitamin B12 supplement (MethB12 and NoMethB12, Meth and NoMeth, respectively). Identical amounts of lactate (2.7 mmol) and TCE (20 μl) were supplied as electron donor and electron acceptor. All four cultures were capable of reductively dechlorinating TCE to VC and ethene. Genomic DNA of the four enrichments was applied on a quad-Dhc-genome microarray in order to characterize the gene content of Dehalococcoides species present in the four enrichments
Project description:In order to investigate the underlying mechanisms of PCB 153 mediated toxicity to Atlantic cod (Gadus morhua), we analyzed the liver proteome of fish exposed to various doses of PCB 153 (0, 0.5, 2 and 8mg/kg body weight) for two weeks and examined the effects on expression of liver proteins using quantitative proteomics. Label-free mass spectrometry enabled quantification of 1272 proteins, and 78 were differentially regulated between PCB 153 treated samples and controls. Two proteins downregulated due to PCB 153 treatment, Glutathione S-transferase theta 1 (GSTT1) and sulfotransferase family protein 1 (ST2B1), were verified using selected reaction monitoring (SRM). Supported by bioinformatics analyses, we concluded that PCB 153 perturbs lipid metabolism in the Atlantic cod liver and that increased levels of lipogenic enzymes indicate increased synthesis of fatty acids and triglycerides.
Project description:The aim of this study is to obtain a systems level understanding of the interactions between Dehalococcoides and corrinoid-supplying microorganisms by analyzing community structures and functional compositions, activities and dynamics in trichloroethene (TCE)-dechlorinating enrichments. Metagenomes and metatranscriptomes of the dechlorinating enrichments with and without exogenous cobalamin were compared. Seven draft genomes were binned from the metagenomes. At an early stage (2 d), more transcripts of genes in the Veillonellaceae bin-genome were detected in the metatranscriptome of the enrichment with exogenous cobalamin compared to the one without cobalamin addition. Among these genes, sporulation-related genes exhibited the highest differential expression when cobalamin was not added, suggesting a possible release route of corrinoids from corrinoid-producers. Other differentially expressed genes include those involved in energy conservation and nutrient transport (including cobalt transport). The most highly expressed corrinoid de novo biosynthesis pathway was also assigned to the Veillonellaceae bin-genome. Targeted qPCR analyses confirmed higher transcript abundances of those corrinoid biosynthesis genes in the enrichment without exogenous cobalamin. Furthermore, Dehalococcoides' corrinoid salvaging and modification pathway was upregulated in response to the cobalamin stress. This study provides important insights into the microbial interactions and roles of members of dechlorinating communities under cobalamin-limited conditions.