A comparative study of hydrocarbon degradation by Marinobacter sp., Rhodococcus sp. and Corynebacterium sp. isolated from different mat systems

Abstract

This comparative study of the hydrocarbon degrading potential of different species and genera of oil degrading bacteria shows that whilst Marinobacter spp. were frequently isolated hydrocarbon degrading organisms from all the sites sampled they had the lowest mineralization rates. In contrast, Rhodococcus isolate O1-NR-LI and Corynebacterium isolate T2W rapidly degraded hexadecane when present either as sole carbon source or in binary and tertiary hydrocarbon model mixtures. Octadecane was metabolized more rapidly in binary and tertiary hydrocarbon mixtures due to solubilisation in hexadecane which increased bio-availability. Mineralisation of the branch-chained alkane, pristane was always slower in hydrocarbon mixtures than for straight chain saturated hydrocarbons. None of the isolates could degrade benzothiophene and when present in model hydrocarbon mixtures it inhibited mineralization until the concentration decreased below the inhibitory threshold.

Keywords:

• alkane degradation
• microbial mats
• Marinobacter
• Rhodococcus
• Corynebacterium