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

Phosphoenolpyruvate (PEP) carboxylase is assumed to be of major import ance as anaplerotic enzyme in the amino acid producing Corynebacterium glutamicum. We constructed PEP carboxylase-negative strains of the wi ld-type and of the L-lysine producer MH20-22B by disruption of the res pective gene. Analysis of these strains and comparison to the parental strains revealed: (i) identical growth characteristics on all media t ested; (ii) identical capacity for lysine production; and (iii) the pr esence of the alternative anaplerotic enzyme PEP carboxykinase in all four strains. These results show that PEP carboxylase is dispensable a s anaplerotic enzyme in C glutamicum and may indicate that PEP carboxy kinase alone can fulfil the anaplerotic function required for growth o n glucose and for lysine production.