A Mycobacterium strain with extended capacities for degradation of gasoline hydrocarbons

A bacterial strain (strain IFP 2173) was selected from a gasoline-polluted aquifer on the basis of its capacity to use 2,2,4-trimethylpentane (isoocta ne) as a sole carbon and energy source. This isolate, the first isolate wit h this capacity to be characterized, was identified by 16S ribosomal DNA an alysis, and 1008 sequence identity with a reference strain of Mycobacterium austroafricanum was found. Mycobacterium sp, strain IFP 2173 used an unusu ally wide spectrum of hydrocarbons as growth substrates, including n-alkane s and multimethyl-substituted isoalkanes with chains ranging from 5 to 16 c arbon atoms long, as well as substituted monoaromatic hydrocarbons. It also attacked ethers, such as methyl t-butyl ether, During growth on gasoline, it degraded 86% of the substrate. Our results indicated that strain IFP 217 3 was capable of degrading 3-methyl groups, possibly by a carboxylation and deacetylation mechanism. Evidence that it attacked the quaternary carbon a tom structure by an as-yet-undefined mechanism during growth on 2,2, 4-trim ethylpentane and 2,2-dimethylpentane was also obtained.