This report describes the first comparative study of petroleum-degrading yeasts, fungi, and bacteria, and their ability to degrade a mixed hydrocarbon substrate. The mixed hydrocarbon substrate employed contained aliphatic, alicyclic, aromatic, and polynuclear aromatic hydrocarbons. The yeasts which were studied included Sporobolomyces sp., Candida sp., C. tropicalis, Hansenula beijerinckii, Aureobasidium pullulans, Rhodotorula glutinis, and R. rubra, and the fungi, Cladosporium resinae, Aspergillus spp., Penicillium spp. The bacterial species were Pseudomonas sp., P. aeruginosa, Vibrio spp., Acinetobacter spp., Leucothrix mucor, Nocardia asteroides, N. corallina, Rhizobium meliloti, R. leguminosarum, and a coryneform. Most of the bacteria and all of the yeasts and fungi were isolated from Chesapeake Bay. Normal alkanes were found to be less susceptible to degradation by bacteria and yeasts as the carbon chain length of the hydrocarbon increased from 10 to 20. Results obtained for some of the fungi showed that there was little correlation between chain length of normal alkane and susceptibility to biodegradation. Cumene, naphthalene, phenanthrene, pristane, 1, 2-benzanthracene, perylene, and pyrene were found to be degraded by microorganisms.
In general, the patterns observed for hydrocarbon utilization were similar for the bacteria, yeasts, and fungi. However, the utilization of hydrocarbons by individual isolates varied significantly. Such information may prove useful in assessing the hydrocarbon-degrading potential of microorganisms.