Role of the Bacillus methanolicus citrate synthase II gene, citY, in regulating the secretion of glutamate in L-lysine-secreting mutants.

ABSTRACT: The thermotolerant, restrictive methylotroph Bacillus methanolicus MGA3 (ATCC 53907) can secrete 55 g of glutamate per liter (maximum yield, 0.36 g/g) at 50 degrees C with methanol as a carbon source and a source of ammonia in fed-batch bioreactors. A homoserine dehydrogenase mutant, 13A52-8A66, secreting up to 35 g of L-lysine per liter in fed-batch fermentations had minimal 2-oxoglutarate dehydrogenase activity [7.3 nmol min(-1) (mg of protein)(-1)], threefold-increased pyruvate carboxylase activity [535 nmol min(-1) (mg of protein)(-1)], and elevated citrate synthase (CS) activity [292 nmol min(-1) (mg of protein)(-1)] and simultaneously secreted glutamate (20 to 30 g per liter) and L-lysine. The flow of carbon from oxaloacetate is split between transamination to aspartate and formation

SUBMITTER: Brautaset T 

PROVIDER: S-EPMC165195 | biostudies-literature | 2003 Jul

REPOSITORIES: biostudies-literature