UTILIZATION OF D-CARNITINE BY PSEUDOMONAS SP AK-1

Pseudomonas sp. AK 1 is able to utilize D-carnitine as sole source of carbon and nitrogen under aerobic conditions. During growth on D-carni tine, a carnitine racemase and a NAD(+)-dependent L-carnitine dehydrog enase are induced. L-Carnitine, glycine betaine, glucose and glycerol prevent the induction of carnitine racemase. The ability to transform D-carnitine into the L-enantiomer was detected in cell-free extracts b ut not with intact cells. The highest carnitine racemase activity was obtained with 50 mM D-carnitine at 39 degrees C and pH 8.5. The partly purified L-carnitine dehydrogenase is very similar in its molecular a nd kinetic properties to L-carnitine dehydrogenases from other bacteri a.