The Role of Biotin-Dependent Pyruvate Carboxylase in<scp>l</scp>-Lysine Production

Abstract

The promotive effect of biotin (200~500 µg/liter) on l-lysine formation was investigated in Brevibacterium lactofermentum. This effect was observed only when glucose or pyruvate was used as sole carbon source, and accompanied with the specific incorporation of 18CO2 into γ-CH2 group of l-lysine. Brev. lactofermentum AJ 3445 (AECr) could grow on pyruvate medium supplemented with biotin at more than 200 µg/liter, while the same growth was observed with the addition of TCA cycle members or glutamate to pyruvate medium. Phosphoenolpyruvate (PEP) carboxylase deficient mutant derived from AJ 3445 could not grow on glucose as sole carbon source, but on glucose plus 200 µg/liter of biotin. AJ 3445 grown on lactate medium containing 500 µg/liter of biotin and KHCO3 contained the biotin-dependent pyruvate carboxylase. These data suggest that this promotive effect of excess biotin on l-lysine formation may be brought about through the activation of pyruvate carboxylase by biotin.