PHOSPHOENOLPYRUVATE CARBOXYLASE IN CORYNEBACTERIUM-GLUTAMICUM IS DISPENSABLE FOR GROWTH AND LYSINE PRODUCTION

Phosphoenolpyruvate (PEP) carboxylase is assumed to be of major importance as anaplerotic enzyme in the amino acid producing Corynebacterium glutamicum. We constructed PEP carboxylase-negative strains of the wild-type and of the L-lysine producer MH20-22B by disruption of the respective gene. Analysis of these strains and comparison to the parental strains revealed: (i) identical growth characteristics on all media tested; (ii) identical capacity for lysine production; and (iii) the presence of the alternative anaplerotic enzyme PEP carboxykinase in all four strains. These results show that PEP carboxylase is dispensable as anaplerotic enzyme in C glutamicum and may indicate that PEP carboxykinase alone can fulfil the anaplerotic function required for growth on glucose and for lysine production.