The enzymology of dicarboxylic acid formation by Corynebacterium sp. strain 7E1C grown on n-alkanes

Cultures of the Gram-positive bacterium Corynebacterium sp. strain 7E1C contained up to 300 mg dodecanedioic acid l−1 after growth on dodecane. Small amounts of tetradecanedioic acid (17 to 45 mg l−1) were produced during growth on tetradecane or methyl tetradecanoate. No dicarboxylic acids were detected after growth on hexadecane, hexadecanoic acid 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 tetradecanedioic acids. The activities and substrate specificities of a number of enzyme activities involved in dicarboxylic acid metabolism were investigated. The specificities of the long-chain acyl-CoA synthetase and thioesterase, alcohol dehydrogenases and β-oxidation are consistent with the accumulation of dodecanedioic acid from dodecane and the lack of production of hexadecanedioic acid from hexadecane. The ω-hydroxy fatty acid may occupy a pivotal position in determining whether significant production of dicarboxylic acid occurs with this organism.