Degradation of nonane by bacteria from Antarctic marine sediment

A microbial enrichment culture tolerant of petroleum hydrocarbons was developed from sediment collected near Casey Station, Antarctica. To select cold-adapted microbes that would degrade diesel, enrichments were cultured at 0degreesC during six successive transfers to fresh medium, with Special Antarctic Blend diesel (SAB) as the sole carbon source. Biodegradation of components of the SAB was then measured in microcosms inoculated with the enrichment culture. After 16 weeks, the amount of biodegradation was small, but nonane (a C9 alkane) had degraded significantly more in inoculated microcosms than in sterile controls. DNA was then extracted from the enrichment cultures and a fragment of the 16S rRNA gene was amplified for denaturing gradient gel electrophoresis. Bands were excised from the gel and, following sequencing, were found to belong to the genera Pseudomonas and Colwellia.