Global molecular analyses of methane metabolism in methanotrophic Alphaproteobacterium, Methylosinus trichosporium OB3b. Part II. metabolomics and 13C-labeling study

作者：Yang Song; Matsen Janet B; Konopka Michael; Green Saxena Abigail; Clubb Justin; Sadilek Martin; Orphan Victoria J; Beck David; Kalyuzhnaya Marina G^*

来源：Frontiers in Microbiology, 2013, 4: 70.

DOI：10.3389/fmicb.2013.00070

• methanotrophic proteobacteria
• serine cycle
• ethylmalonyl-CoA pathway in methanotrophs
• metabolic fluxes labeling

In this work we use metabolomics and C-13-labeling data to refine central metabolic pathways for methane utilization in Methylosinus trichosporium OB3b, a model alphaproteobacterial methanotrophic bacterium. We demonstrate here that similar to non-methane utilizing methylotrophic alphaproteobacteria the core metabolism of the microbe is represented by several tightly connected metabolic cycles, such as the serine pathway, the ethylmalonyl-CoA (EMC) pathway, and the citric acid (TCA) cycle. Both in silico estimations and stable isotope labeling experiments combined with single cell (NanoSIMS) and bulk biomass analyses indicate that a significantly larger portion of the cell carbon (over 60%) is derived from CO2 in this methanotroph. Our(13) C-labeling studies revealed an unusual topology of the assimilatory network in which phosph(enol) pyruvate/pyruvate interconversions are key metabolic switches. A set of additional pathways for carbon fixation are identified and discussed.

• 出版日期2013-4-3