CARNITINE ACTS AS A COMPATIBLE SOLUTE IN BREVIBACTERIUM LINENS

Carnitine is a trimethyl amino acid found at relatively high concentra tions in materials of animal origin. Exogenously provided L-carnitine was found to stimulate growth of Brevibacterium linens ATCC 19391 in m edia with inhibitory osmotic strength. Its osmoprotective ability was as potent as that of glycine betaine. Electrophoretic and spectroscopi c (NMR) analysis showed that this compound is only transiently accumul ated, but in significant amounts, by B. linens under hyperosmotic stre ss and is converted into glycine betaine. The L-carnitine/glycine beta ine pathway is inducible by L-carnitine in B. linens. The D-enantiomer did not improve growth of B. linens, even though this solute is accum ulated by B. linens at the same level as glycine betaine. The two isom eric forms of carnitine repress the build-up of ectoine, the main endo genous osmolyte in B. linens.