13C NMR studies of bacterial fermentations

In vitro fermentation by human faecal bacteria of total and purified dietary fibres from brown seaweeds

“…Thus, TFOM values reflect sugar metabolism (Auffret et al 1991). Although some acetate can result from autotrophic acetogenesis by CO, reduction (Lajoie et al 1988;Grivet et al 1992) and some SCFA can be produced from protein fermentation (putrefaction;Macfarlane et al 1992), most of the SCFA production in the present study was assumed to originate from sugar fermentation. The validity of the TFOM calculation also relies on the accuracy of the total sugar content determination.…”

In-cell NMR: Why and how?

“…Concerning microorganisms, we mention works on amino acid biosynthesis by Corynebacterium glutamicum, a bacterium used for industrial production of amino acids [740][741][742], glucose metabolism of the pathological S. aureus [743,744], of the yeast S. cerevisiae [745][746][747][748], of rumen bacteria [749][750][751] and of Lactococcus lactis [752][753][754], formaldehyde [755] and acetate [756] utilization by E. coli, and acetate, methanol or methylamine utilization by methylotrophic strains [757][758][759][760].…”

13C NMR Flux Ratio Analysis of Escherichia coli Central Carbon Metabolism in Microaerobic Bioprocesses

“…Active pathways and catalytic capacities in microorganisms are often highly sensitive to the cell environment. For example, oxygen supply can have qualitative effects on biocatalytic configuration and rates. − This paper addresses the behavior of wild-type E. coli MG1655 cells carrying a high copy number plasmid under microaerobic conditions ([O 2 ] < 0.02 mmol/L), a situation that is encountered frequently in nature as well as in the biotechnology industry. , Only a few stable isotope labeling experiments have so far been pursued to investigate anaerobic and/or microaerobic metabolism. − In this paper, information on active metabolic topology and carbon pathway flux ratios was obtained from the aforementioned E. coli strain under microaerobic conditions, which is a typical biocatalyst configuration, using biosynthetic fractional 13 C-labeling of proteinogenic amino acids with a mixture of 10% [ 13 C 6 ]-glucose/90% unlabeled glucose as the sole carbon source and 2D [ 13 C, 1 H]-correlation NMR spectroscopy for analysis of the resulting products. , Analysis of the breakdown of the six-carbon skeleton of glucose from the 13 C fine structures allows both determination of ratios of metabolic fluxes and an efficient analysis of the bioreaction network topology. ,− …”