Utilization of lipids as sole carbon sources by thermophilic fungi

Abstract

The ability of six thermophilic fungi to utilize fatty acids and glycerol as sole carbon sources for growth was studied in liquid shake-cultures at 45°C. These fungi, which were found occurring in stacks of oil palm kernels at the oil mills in Nigeria, included Chaetomium thermophile var. coprophile COONEY and EMERSON, Chaetomium thermophile var. dissitum COONEY and EMERSON, Mucor pusillus LINDT, Thermoascus aurantiacus MIEHE sensu APINIS, Thermoascus crustaceus (APINIS and CHESTERS) STOLK, and Humicola lanuginosa (GRIFFON and MAUBLANC) BUNCE. All the organisms produced the best growth on stearic, palmitic, oleic, and myristic acids with the exception of C. thermophile var. coprophile which did not grow on myristic acid. They all had an average growth on behenic, acetic, butyric, and valeric acids with the exception of T. crustaceus and H. lanuginosa which did not utilize butyric acid, and M. pusillus and H. lanuginosa which produced no growth on valeric acid. The other fatty acids tested, capric, caprylic, lauric, linoleic, and arachidic acids, were not available to any of them, while glycerol was utilized by all. The six organisms produced good growth and indicated acid production on a Nile blue sulphate/groundnut oil medium. Their involvement in the biodeterioration of oil palm produce during processing and in storage was suggested.