Riboflavin Deficiency and Respiratory Flavoproteins of Bacillus subtilis

Summary: A mutant of Bacillus subtilis which required riboflavin for growth was grown with limiting or excess riboflavin. Riboflavin deficiency decreased the content of flavin, particularly of FMN in the particulate fraction. The activities of particulate succinate and NADH dehydrogenases also decreased, whereas α-glycerophosphate dehydrogenase activity did not alter. When riboflavin was added back to a starved culture, the bacterial flavin content recovered quickly, even when chloramphenicol was present. Succinate dehydrogenase activity also recovered, but this increase was inhibited by chloramphenicol.