Molecular characterization of a new strain of Aspergillus and ricinoleic acid production from castor oil by the fungus

The derivatives of castor oil have wide industrial applications. Different strains were isolated that metabolize the castor oil. Among these, Isolate D which was later identified as Aspergillus flavus BU22S was selected for further study. Major metabolite produced by the strain was extracted and identified using mass spectrometry (MS) followed by HPLC analysis. The metabolite was found to be ricinoleic acid. Ricinoleic acid is widely used in polymer industries, cosmetics, pharmaceutical industries, lubricants, and in textiles. The product yield of the selected isolate was studied with different castor oil concentrations under different process conditions. Agitation speed as well as oil concentration were found to have a significant effect on ricinoleic acid production. The best yield, that is, 79.5 g/kg of total oil was obtained at a lower agitation speed. The strain consumed some amount of oil, which can be reduced from 90% to 29% by optimizing the process parameters.