Boosting Anaplerotic Reactions by Pyruvate Kinase Gene Deletion and Phosphoenolpyruvate Carboxylase Desensitization for Glutamic Acid and Lysine Production in Corynebacterium glutamicum.
Adv Biochem Eng Biotechnol 2017 ;159:181-198
Laboratory of Microbial Physiology, Research Faculty of Agriculture, Hokkaido University, Kita-9 Nishi-9, Kita-ku, Sapporo, 060-8589, Japan.
In the 1980s, Shiio and coworkers demonstrated using random mutagenesis that the following three phenotypes were effective for boosting lysine production by Corynebacterium glutamicum: (1) low-activity-level citrate synthase (CS(L)), (2) phosphoenolpyruvate carboxylase (PEPC) resistant to feedback inhibition by aspartic acid (PEPC(R)), and (3) pyruvate kinase (PYK) deficiency. Here, we reevaluated these phenotypes and their interrelationship in lysine production using recombinant DNA techniques.The pyk deletion and PEPC(R) (D299N in ppc) independently showed marginal effects on lysine production, but both phenotypes synergistically increased lysine yield, demonstrating the importance of PEPC as an anaplerotic enzyme in lysine production. Read More