Production of Sophorolipid Biosurfactant by Insect Derived Novel Yeast F.a., Sp. Nov., and Its Antifungal Activity Against Plant and Human Pathogens

Biosurfactants are potential biomolecules that have extensive utilization in cosmetics, medicines, bioremediation and processed foods. Yeast produced biosurfactants offer thermal resistance, antioxidant activity, and no risk of pathogenicity, illustrating their promising use in food formulations. The present study is aimed to assess potential of biosurfactant screened from a novel yeast and their inhibition against food spoilage fungi. A novel asexual ascomycetes yeast strain CIG-6A producing biosurfactant, was isolated from the gut of stingless bee from Churdhar, HP, India. The phylogenetic analysis revealed that the strain CIG-6A was closely related to , showing 94.38% sequence similarity in the D1D2 region for which the name f.a., sp. nov., is proposed. The strain CIG-6A was able to produce sophorolipid biosurfactant under optimum conditions. Sophorolipid biosurfactant from strain CIG-6A effectively reduced the surface tension from 72.8 to 35 mN/m. Sophorolipid biosurfactant was characterized using TLC, FTIR, GC-MS and LC-MS techniques and was a mixture of both acidic and lactonic forms. Sophorolipid assessed promising activity against pathogenic fungi viz. (MTCC 9913), (MTCC 350), and (MTCC 2190). The inhibitory effect of biosurfactant CIG-6A against was studied and MIC was 49 μgm/ml, further confirmed through confocal laser scanning microscopy. We illustrated the antifungal activity of sophorolipid biosurfactant from genus for the first time and suggested a novel antifungal compound against food spoilage and human fungal pathogen.