Comparative Metabolomics of Mycoplasma bovis and Mycoplasma gallisepticum Reveals Fundamental Differences in Active Metabolic Pathways and Suggests Novel Gene Annotations
نویسنده :
تاریخ انتشار : 1396/08/22
Mycoplasmas are simple, but successful parasites that have the smallest
genome of any free-living cell and are thought to have a highly streamlined cellular
metabolism. Here, we have undertaken a detailed metabolomic analysis of two species,
Mycoplasma bovis and Mycoplasma gallisepticum, which cause economically
important diseases in cattle and poultry, respectively. Untargeted gas chromatographymass
spectrometry and liquid chromatography-mass spectrometry analyses of mycoplasma
metabolite extracts revealed significant differences in the steady-state levels
of many metabolites in central carbon metabolism, while 13C stable isotope labeling
studies revealed marked differences in carbon source utilization. These data were
mapped onto in silico metabolic networks predicted from genome wide annotations.
The analyses elucidated distinct differences, including a clear difference in glucose
utilization, with a marked decrease in glucose uptake and glycolysis in M. bovis compared
to M. gallisepticum, which may reflect differing host nutrient availabilities. The
13C-labeling patterns also revealed several functional metabolic pathways that were
previously unannotated in these species, allowing us to assign putative enzyme
functions to the products of a number of genes of unknown function, especially in
M. bovis. This study demonstrates the considerable potential of metabolomic analyses
to assist in characterizing significant differences in the metabolism of different
bacterial species and in improving genome annotation.