Physiological studies on Vitreoscilla stercoraria

Vitreoscilla stercoraria ATCC 15218 was studied to elucidate some of its physiological characteristics. The initial optimal pH for the organism was found to be 7.5 to 7.7. The characteristics of the growth curve of the organism showed that its growth in shake cultures is by increasing trichome number up to approximately 15 hr and by increasing trichome length after 15 hr. Nutritional studies indicated that it is auxotrophic for biotin, thiamine, and l-arginine, and it appears to be an obligate amino acid utilizer because only protein hydrolysates or known amino acid mixtures would support growth.