Isolation and Characterization of Three New Crude Oil Degrading Yeast Strains, Candida parapsilosis SK1, Rhodotorula mucilaginosa SK2 and SK3

Bioremediation using yeasts is an alternative way to minimize the effects of oil spillage on soil. This paper aims to establish a bioremediation protocol involving the optimization of physicochemical parameters. In this regard, three new yeast strains, SK1, SK2 and SK3, were isolated from hydrocarbon-contaminated samples from the Fez-Meknes region, Morocco. These isolates were identified as new species of Candida parapsilosis (SK1) and Rhodotorula mucilaginosa (SK2 and SK3), respectively, based on the similarity of their ITS region. The kinetic analysis of the process of degradation of petroleum oils are highlighted. These analyses were based on the degradation kinetics, and biomass formation using gravimetric analysis and gas chromatography coupled with mass spectrometry techniques. The strains were able to degrade 68% of the total petroleum hydrocarbon in 21 days, as the sole carbon source. The addition of glucose increased the rate at which crude oil was consumed by the isolates. Our results suggest that inoculants based on Candida parapsilosis (SK1) and Rhodotorula mucilaginosa (SK2 and SK3) cells have potential application in the biodegradation of crude oil and possibly in the degradation of other related aromatic compounds.