In vivo 13C-NMR studies of polymer synthesis in Rhizobium meliloti M5N1 strain

The use of in vivo 13C‐NMR approach for the monitoring of the synthesis of various polymers within cells of Rhizobium meliloti (M5N1 strain) is reported. Significant differences in polymer biosynthesis have been shown as a function of the metabolic state of the cells and the labeled carbon source used. Consumption of carbon source and produced glycogen was complete with mid‐exponential phase harvested cells. This was not the case with stationary phase harvested cells, for which polyhydroxybutyrate synthesis was higher and gluconate synthesis was lower than the former. [1‐13C]fructose‐grown cells produced more exopolysaccharide and polyhydroxybutyrate, but less β‐(1,2) glucan and gluconate than [1‐13C]glucose‐grown cells. This approach offers a suitable tool to examine the kinetics of polymer biosynthesis by Rhizobia. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 58:250–253, 1998.