Growth of Leptospira interrogans Serotype patoc

Leptospira interrogans serotype patoc exhibited an increasing growth response when cultivated in media containing from 50 to 250 ,ug of sodium oleate per ml. Leptospiral growth in the presence of 250 ,ug of sodium oleate per ml was as good as that in the basal medium which contained 700 Mig of oleic acid (in Tween 80) per ml. When positional isomers of oleic acid (9-octadecenoic acid) were present at a concentration of 200 ,ug/ml, the 2and 8-isomers were not readily utilized, whereas the 3-, 4-, 6-, 11-, 15-, and 16-isomers gave a growth response equivalent to that of oleic acid, i.e., the 9-isomer. The 5-, 7-, 10-, 12-, 13-, 14-, and 17-isomers of octadecenoic acid induced growth responses which differed in magnitude but were intermediate to those of 2-18:1 and 3-18:1. When 200 Mg of either 2or 3-octadecenoic acid per ml was added in addition to 200 Mug of 9-18:1 per ml, there was further enhancement of growth above that with 200 MAg of 9-18:1 alone; 400 MAg of 9-18:1 alone per ml inhibited growth of this organism. The growth response of leptospira to octadecenoic acids differed from that of mammalian cells, suggesting the presence of different enzymes in the two systems for the utilization of these substrates.