Process for isolation of carnitinehydrolyase and an effector from enterobacteriaceae and use thereof to prepare carnitine

A process for microbiologically producing L(-)-carnitine by stereospecific hydration of crotonobetaine and crotonobetaine derivatives, which comprises:

• (a) isolating from strains belonging to the family Enterobacteriaceae an enzyme carnitinehydrolyase per se inactive and an effector which in the presence of the enzyme activates it making it capable of stereoselectively hydrating crotonobetaine into L(-)-carnitine, by
• (i) cultivating said strains under anaerobic conditions on a complete culture medium containing D,L-carnitine and/or crotonobetaine;
• (ii) disrupting the Enterobacteriaceae cells thus obtaining a raw protein extract;
• (iii) chromatographying the raw protein extract on a support comprising hydrophobic anionic exchange resins thus achieving the isolation and immobilization of carnitinehydrolyase on the support and producing an eluate which comprises a protein fraction and the effector;
• (iv) ultrafiltrating the eluate thus obtaining a filtrate containing the effector and practically free from proteins and carnitinehydrolyase;
• (b) contacting a solution of crotonobetaine or crotonobetaine derivatives with carnitinehydrolyase in the presence of the effector thus obtaining L(-)-carnitine;
• and
• (c) separating L(-)-carnitine from unreacted crotonobetaine and the effector.