抄録
It was recognized that the remarkable growth of Ochromonas malhamensis in the absence of cyanocobalamin in the Ford's medium during long incubation was due to methionine added to the medium. On the other hand the addition of methionine proved to improve the growth response of the organism to the vitamin without affecting the inoculated blank. The findings show that Ochromonas seems to have similar requirements for vitamin B_<12> and methionine to E. coli 113-3 or 215.