Isolation of Gram positive n-alkane degraders from a hydrocarbon contaminated Mediterranean shoreline

Aims: To investigate the petroleum hydrocarbon (HC)-degrading potential ofindigenous micro-organisms in a sandy Mediterranean coast, accidentally contaminatedwith petroleum-derived HCs.Methods and Results: Using culturable methods, a population of Gram-positiven-alkane degraders was detected in the contaminated soil. Five isolates,identified as one Nocardia, two Rhodococcus and two Gordonia strains, wereable to degrade medium- and long-chain n-alkanes up to C36 as assessed bygrowth assays and gas chromatography-mass spectrometry analysis. Divergingalkane hydroxylase-encoding genes (alkB) were detected by PCR, using degeneratedprimers, in all the strains; multiple sequences were obtained from theNocardia strain, while only one alkB gene was detected in the Rhodococcus andGordonia strains. The majority of the alkB sequences were related to RhodococcusalkB2, but none was identical to it.Conclusions: Actinomycetes might have a key role in bioremediation ofn-alkane-contaminated sites under dry, resource-limited conditions, such asthose found in the Mediterranean shorelines.Significance and Impact of the Study: To our knowledge, this is the first studyon the bioremediation potential in Mediterranean contaminated beaches.