Hydrocarbon degradation by Antarctic coastal bacteria

Bacterial cultures obtained through selective enrichment of beach sand coll ected GO days and one year after treatment of sites in a pilot oil spill tr ial conducted at Airport Beach, Vestfold Hills, East Antarctica, were exami ned for the ability to degrade n-alkanes and phenanthrene. The effects of d ifferent hydrocarbon mixtures (Special Antarctic Blend [SAB] and BP-Visco), fish oil [orange roughy]) and inoculation of replicate sites with water fr om Organic Lake (previously shown to contain hydrocarbon-degrading bacteria ) on the indigenous microbial population were examined. Of the cultures obt ained, those from sites treated with SAB and BP-Visco degraded n-alkanes mo st consistently and typically to the greatest extent. Two mixed cultures ob tained from samples collected at 60 days and two isolates obtained from the se cultures extensively degraded phenanthrene. 1-Hydroxy-naphthoic acid for med the major phenanthrene metabolite. Lower levels of salicylic acid, l-na phthol 1,4-naphthaquinone and phenanthrene 9-10 dihydrodiol were detected i n extracts of phenanthrene grown cultures. This study shows that under labo ratory conditions indigenous Antarctic bacteria can degrade n-alkanes and t he more recalcitrant polycyclic aromatic hydrocarbon, phenanthrene. The enr ichment of hydrocarbon degrading microorganisms in Antarctic ecosystems exp osed to hydrocarbons is relevant for the long term fate hydrocarbon spills in this environment.