IN-VIVO C-13-NMR STUDIES OF POLYMER SYNTHESIS IN RHIZOBIUM-MELILOTI M5N1 STRAIN

The use of in vivo C-13-NMR approach for the monitoring of the synthes is of various polymers within cells of Rhizobium meliloti (M5N1 strain ) is reported. Significant differences in polymer biosynthesis have be en shown as a function of the metabolic stale of the cells and the lab eled carbon source used. Consumption of carbon source and produced gly cogen was complete with mid-exponential phase harvested cells, This wa s not the case with stationary phase harvested cells, for which polyhy droxybutyrate synthesis was higher and gluconate synthesis was lower t han the former. [1-C-13]fructose-grown cells produced more exopolysacc haride and polyhydroxybutyrate, but less beta-(1,2) glucan and glucona te than [1-C-13]glucose-grown cells. This approach offers a suitable t ool to examine the kinetics of polymer biosynthesis by Rhizobia. (C) 1 998 John Wiley & Sons, Inc.