An aspergillus isolate and its secondary metabolites from lake Elementaita in Kenya

Abstract

The soda lakes provide a high biodiversity of halophilic and alkaliphilic fungi. The fungus in this study was isolated from sediments collected from Lake Elmentaita in Kenya. The effect of pH and sodium chloride on growth was done on Malt Extract Agar (MEA) and Potato Dextrose Agar (PDA) media. Fermentation of fungal isolate in 500 ml conical flasks was done in fourteen days’ duration on a shaker. Extraction of crude fermentation solution was done using the solvents, Ethyl acetate and hexane in the ratio 2:1 respectively. Molecular characterization of the fungus was done using the18s rDNA Gas-chromatography-Mass spectrophotometry (GC-MS) analysis revealed seventeen secondary metabolites produced by the fungus. The fungus grew well at alkaline pH of 9 to12 and a temperature range of 26°C to 30°C. Growth was only observed on 0% to 10% sodium chloride. The culture-dependent assays and GC-MS analysis showed that the fungus produces bioactive compounds that can be applied in biotechnology research. Moreover, molecular analysis grouped the isolate as a close relative to the genus Aspergillus.