Project description:Enrichment of anaerobic nitrate-dependent methanotrophic Candidatus Methanoperedens nitroreducens archaea from an Italian paddy field soil
Project description:Natural and anthropogenic wetlands are main sources of the atmospheric greenhouse gas methane. Methane emissions from wetlands are mitigated by methanotrophic microorganisms and by processes at the oxic-anoxic interface, such as sulfur cycling, that reduce the activity of methanogens. In this study, we obtained a pure culture (strain HY1) of a versatile wetland methanotroph that oxidizes various organic and inorganic compounds. This strain represents (i) the first isolate that can aerobically oxidize both methane and reduced sulfur compounds and (ii) a new alphapoteobacterial species, named Candidatus Methylovirgula thiovorans. Genomic and proteomic analyses showed that soluble methane monooxygenase and XoxF-type alcohol dehydrogenases are the only enzymes for methane and methanol oxidation, respectively. Unexpectedly, strain HY1 harbors various pathways for respiratory sulfur oxidation and oxidized reduced sulfur compounds to sulfate using the Sox-rDsr pathway (without SoxCD) and the S4I system. It employed the Calvin-Benson-Bassham cycle for CO2 fixation during chemolithoautotrophic growth on the reduced sulfur compounds. Methane and thiosulfate were independently and simultaneously oxidized by strain HY1 for growth. Proteomic and microrespiratory analyses showed that the metabolic pathways for methane and thiosulfate oxidation were induced in the presence of their substrates. The discovery of this versatile methanotroph demonstrates that methanotrophy and thiotrophy is compatible in a single bacterium and adds a new aspect to interactions of methane and sulfur cycles in oxic-anoxic interface environments.
Project description:mRNA expression profiles of trypanosomes from two discrete bloodstream form stages of the parasite (slender and stumpy forms), as well as during the transition of the stumpy population to the procyclic life-cycle stage were studied. Our analysis represents the first comparison of in vivo derived pleomorphic slender cells with genetically identical stumpy forms, and a first analysis of the dynamic changes in mRNA profile that accompany the transition to procyclic forms.
Project description:mRNA expression profiles of trypanosomes from two discrete bloodstream form stages of the parasite (slender and stumpy forms), as well as during the transition of the stumpy population to the procyclic life-cycle stage were studied. Our analysis represents the first comparison of in vivo derived pleomorphic slender cells with genetically identical stumpy forms, and a first analysis of the dynamic changes in mRNA profile that accompany the transition to procyclic forms. Twenty nine RNA samples were generated (5 biological replicates of Stumpy (0h), 1h, 6h, 18h and 48h, and 4 biological replicates of slender forms. Four arrays failed QC.
