Microbiological oxidation of long-chain aliphatic compounds. Part II. Branched-chain alkanes
In a medium containing glucose, the yeast Torulopsis gropengiesseri converts long-chain methyl-branched alkanes into glycolipids by one or more of three metabolic pathways, namely, (i) alkane → alkan-1-ol → alkanoic acid →ω- and/or ω-1-hydroxyalkanoic acid → glycolipid, (ii) alkane → alkan-1-ol → glycolipid, and (iii) alkane → alkan-1-ol →ω- and/or ω-1-hydroxyalkan-1-ol → glycolipid. Pathways (ii) and (iii) are important for the metabolism of alkan-1-ols whose dehydrogenation to alkanoic acids is inhibited by one or more methyl substituents close to the primary alcohol group. Initial oxidation of 2,2-dimethylhexadecane occurs exclusively at the less hindered terminal position which is the predominant site of the initial oxidation of 2-methyl-hexadecane. Alkanoic acids and alkan-1-ols which have methyl substituents close to the functional group give ω- and ω-1-hydroxy-derivatives; alkanoic acids and alkan-1-ols which have methyl substituents at the ω-1-position give ω-hydroxy-derivatives.