Project description:Our goal is to convert methane efficiently into liquid fuels that may be more readily transported. Since aerobic oxidation of methane is less efficient, we focused on anaerobic processes to capture methane, which are accomplished by anaerobic methanotrophic archaea (ANME) in consortia. However, no pure culture capable of oxidizing and growing on methane anaerobically has been isolated. In this study, Methanosarcina acetivorans, an archaeal methanogen, was metabolically engineered to take up methane, rather than to generate it. To capture methane, we cloned the DNA coding for the enzyme methyl-coenzyme M reductase (Mcr) from an unculturable archaeal organism from a Black Sea mat into M. acetivorans to effectively run methanogenesis in reverse. The engineered strain produces primarily acetate, and our results demonstrate that pure cultures can grow anaerobically on methane.
2015-12-20 | GSE66445 | GEO
Project description:Methane cycling microbes in cyanobacterial bloom aggregates
Project description:RNA-Seq profiling of Methylomicrobium alcaliphilum strain 20Z grown in batch on methane. The RNA-Seq work is one part of a systems approach to characterizing metabolism of 20Z during growth on methane. We demonstrate that methane assimilation is coupled with a highly efficient pyrophosphate-mediated glycolytic pathway, which under O2 limitation participates in a novel form of fermentation-based methanotrophy. This surprising discovery suggests a novel mode of methane utilization in oxygen-limited environments, and opens new opportunities for a modular approach towards producing a variety of excreted chemical products using methane as a feedstock.
Project description:RNA-Seq profiling of Methylomicrobium alcaliphilum strain 20Z grown in batch on methane. The RNA-Seq work is one part of a systems approach to characterizing metabolism of 20Z during growth on methane. We demonstrate that methane assimilation is coupled with a highly efficient pyrophosphate-mediated glycolytic pathway, which under O2 limitation participates in a novel form of fermentation-based methanotrophy. This surprising discovery suggests a novel mode of methane utilization in oxygen-limited environments, and opens new opportunities for a modular approach towards producing a variety of excreted chemical products using methane as a feedstock. Four replicates of batch growth
Project description:Ruminant livestock are one of the major contributors to carbon emission contributing the global warming issue. Methane (CH4) produced from enteric microbial fermentation of feed in the reticulo-rumen are known to differ between sheep with different digestive function and fermentation products such as metabolites. However, the molecular mechanism underpinning differences in methane emission remains to be fully elucidated. We extracted a membrane and cytosolic protein fraction of rumen epithelium proteins from both high (H) and low (L) CH4 emitting sheep. Protein abundance differences between the phenotypes were quantified using SWATH-mass spectrometry. We identified 92 proteins annotated as cell surface transporters, of which only solute carrier family (SLC) 40A1 had a greater fold change of protein expression in the high methane emission phenotype. The main difference in protein abundance we found were related to the metabolism of glucose, lactate and processes of cell defence against microbes in the epithelium of sheep in each group. To best of our knowledge, this represents one of the most comprehensive proteomes of ovine rumen epithelium to date.
Project description:Comparative transcriptomic analysis between methane- and methane plus xylose- grown cultures revealed different transcriptional responses of pXyl M. alcaliphilum 20Z strain on diffirent growth modes.
Project description:We report here a methanotroph, Methylotuvimicrobium buryatense 5GB1C, that consumes methane at 500ppm at rates several times higher than any previously published. Analyses of bioreactor-based performance and RNAseq based transcriptomics suggest that this superior ability to utilize low methane is based at least in part on an extremely low non-growth associated maintenance energy and on a 5-fold higher methane specific affinity than previous reports.