Isolation of oleaginous fungi from natural sources, and fatty acid profile of Cunninghamella echinulata

Abstract

Oleaginous microorganisms accumulate 20% or more of their dry weight as lipid. In the present study, 247 fungal isolates were obtained from different types of soil, marine water, and food, and screened for their ability to accumulate considerable amounts of lipid. A primary screening with Nile red staining was followed by sulfo-phosphovanillin reaction. The most potent isolate was identified employing both morphological and molecular methods as the Zygomycetous fungus, Cunninghamella echinulata AUMC14396. The lipid of this fungus was extracted, transesterified, and analyzed via GC-MS to elucidate the fatty acid (FA) composition. The fatty acid profile revealed the presence of various fatty acids with different concentrations. Of the total fatty acids, saturated FAs comprised 44.49%, while monounsaturated FAs were 19.91%, and polyunsaturated fatty acids (PUFAs) were 35.61%. The most predominant species was linoleic acid (13.79%) followed by stearic (12.78%) and oleic (12.50%) acids. The polyunsaturated fatty acid, gamma linolenic acid was present in a considerable amount (8.02%). Other important PUFAs were also found in the fatty acid profile such as arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid. The results of this study were discussed in respect to the important applications in the context of production of pharmaceuticals and nutraceuticals.