Biodegradation of Oil Pollutants by Yeasts and Yeast-Like Fungi.

摘要

In exploring the feasibility of the use of microbial systems for the facilitated biodegradation of waste oils, yeasts and yeast-like fungi from marine, freshwater and terrestrial sources were screened for their ability to utilize hydrocarbons. Mixed cultures of selected fungi, mainly isolates of Candida lipolytica and C. maltosa grew in oil-enriched freshwater or seawater systems fortified with ammonium sulfate or urea. Neither of these yeasts demonstrated capacities for pathogenicity. In estuarine test plots, both species showed affinity for hydrocarbon substrates and did not spread into adjacent pristine habitats. Straight-chained hydrocarbons (C9-C18) were primary substrates, but napthalene and biphenyl content of a synthetic crude decreased concomitantly with utilization of alkanes. Actively growing cells rapidly emulsified light crudes and their refinery fractions, but spent culture broths and dead cells also had emulsifying capacity. Candida lipolytica, but not C. maltosa produced inducible extracellular proteinases. The use of yeasts in mixed culture systems for facilitating the biodegradation of spent oil in confined systems is recommended. (Author)