Yeasts capable of degrading hydrocarbons include genera of Yarrowia lipolytica, Candida tropicalis, Candida albicans, and Debaryomyces hansenii. The alkane-utilizing yeast Y. lipolytica degrades very efficiently hydrophobic substrates (HS) such as triglycerides (fats, oils), alkanes, and fatty acids. It has been observed that Y. lipolytica is the predominant yeast form during alkane degradation and emulsifier production. The study of hydrocarbon biodegradation by native microorganisms is of extreme ecological importance. The actual contribution of yeasts in the biodegradation of hydrocarbons in the environment may be more important than that previously expected, considering the metabolic diversity demonstrated for yeasts.