Biotechnology Letters, Vol.29, No.5, 779-784, 2007
A fundamental dual regulatory role of citrate on the biosyntheses of thuringiensin and poly-beta-hydroxybutyrate in Bacillus thuringiensis YBT-032
The production of alpha-ketoglutarate, adenine, thuringiensin production rate and thuringiensin yield on glucose consumed increased by 22%, 36%, 40% and 40%, respectively, in presence of 2 g citrate/l. However, citrate decreased pyruvate production, poly-beta-hydroxybutyrate (PHB) production rate and PHB yield by 62%, 31% and 45%, respectively. The activities of pyruvate kinase and glucose-6-phosphate dehydrogenase were 36%-45% lower and 50%-120% higher than those of the control, respectively. The results suggest that citrate regulated the carbon flux to synthesis of adenine present in thuringiensin with a higher efficiency of utilization of glucose by decreasing PHB synthesis.