THE ENZYMOLOGY OF DICARBOXYLIC-ACID FORMATION BY CORYNEBACTERIUM SP STRAIN 7E1C GROWN ON N-ALKANES

Cultures of the Gram-positive bacterium Corynebacterium sp. strain 7E1 C contained up to 300 mg dodecanedioic acid l-1 after growth on dodeca ne. Small amounts of tetradecanedioic acid (17 to 45 mg l-1) were prod uced during growth on tetradecane or methyl tetradecanoate. No dicarbo xylic acids were detected after growth on hexadecane, hexadecanoic aci d or 16-hydroxyhexadecanoic acid. Studies on the rates of degradation of exogenous dicarboxylic acids showed that this is not a significant factor influencing the accumulation of dodecanedioic and tetradecanedi oic acids. The activities and substrate specificities of a number of e nzyme activities involved in dicarboxylic acid metabolism were investi gated. The specificities of the long-chain acyl-CoA synthetase and thi oesterase, alcohol dehydrogenases and beta-oxidation are consistent wi th the accumulation of dodecanedioic acid from dodecane and the lack o f production of hexadecanedioic acid from hexadecane. The omega-hydrox y fatty acid may occupy a pivotal position in determining whether sign ificant production of dicarboxylic acid occurs with this organism.