Enzymatic studies on autotrophically, mixotrophically and heterotrophically grown Nitrobacter agilis with special reference to nitrite oxidase.

Nitrobacter agilis was grown autotrophically on nitrite, mixotrophically on nitrite together with either acetate or pyruvate and heterotrophically on acetate and casamino acids, pyruvate and casamino acids or pyruvate and nitrate. The enzymatic activities differed most in the key enzymes of lithotrophic metabolism. Nitrite oxidase was repressed 90% in 10 days after transition to heterotrophic growth and was no longer detectable after several transfers. The induction of nitrite oxidase began after a lag of 2 days and reached the autotrophic level after 7 days when pyruvate was the carbon and energy source and after 9 days using acetate.