MECHANISM OF GLUCONATE SYNTHESIS IN RHIZOBIUM-MELILOTI BY USING IN-VIVO NMR

The dehydrogenation of [1-C-13]- and [2-C-13]glucose into gluconate wa s monitored by NMR spectroscopy in living cell suspensions of two Rhiz obium meliloti strains. The synthesis of gluconate was accompanied, in the cellular environment, by the formation of two gluconolactones, a gamma-lactone being detected in addition to the expected delta-lactone , These lactones - as well as the gluconate - could be further metabol ized by the cells, The delta-lactone was utilized faster than the gamm a-lactone, The presence - in significant amounts - and the relative st ability of the lactones raise the question of their possible physiolog ical significance. (C) 1997 Federation of European Biochemical Societi es.