Strain improvement of Phosphate solubilizing fungal strains for the production of lipase

Abstract

A laboratory study was conducted to isolate, investigate and enhance the phosphate solubilization efficiency of certain isolated fungal strains viz., Aspergillus niger, Aspergillus fumigatus, Penicillium sp. These fungal strains were isolated from the rhizosphere of paddy fields in Tamilnadu, India and screened for phosphate solubilization. The enhancement of Lipase activity of these strains was studied through mutagenesis: UV, sodium azide and ethyl methane sulphonate. The mutant ANuv50 exhibited 32.72% increased efficiency for Lipase activity in the presence of sucrose as a carbon source and 91.49% increased efficiency for Lipase activity in the presence of olive oil as a carbon source compared to the wild strains. Similarly, the Lipase activity by sodium azide mutant (ANsa90) was 61.11% higher in the presence of sucrose as a carbon source, 107.60%  higher in the presence of olive oil as a carbon source and EMS mutant  (ANems150) was 137.65% higher  in the presence of sucrose as a carbon source, 98.93%  higher in the presence of olive oil as a carbon source than the wild strain. The efficient strains were further studied for the effect of carbon and nitrogen source on Lipase activity. Significance of the findings is discussed in detail.