Abstracto

Evaluation of Lipase Production from A. Japonicus Using Various Vegetable Oil Substrates and Physico-Chemical Factors Affecting Lipase Activity by Response Surface Methodology

K. Sobha, N. Lalitha, A. Ratna Kumari, K.V. Rajesh, Mahendra Kumar Verma1

Lipases from plant, animal and microbial sources are of great importance in industrial applications owing to their varied properties and functions. In this study, Aspergillus japonicus MTCC 1975 was cultured in a production medium containing Malt extract (20g/L), Wheat mill bran (10g/L), Soy flour (5g/L), and Whey (1%) for production of lipase varying the design variables pH, temperature and oil substrate concentration. After 72 hours of incubation in the production medium, the pseudomycelium was separated and the culture supernatant was assayed for enzyme activity. Initial experiments were done with ten different vegetable oils, varying pH and temperature on one variable at a time method. High yields of the enzyme and the enzyme activity were obtained with olive and sesame oils as substrate inducers in the medium. Further experiments with olive oil substrate were carried out based on three level full factorial design of response surface methodology and the optimal values of the variables were identified by solving the regression equations using Matlab. Experimental results demonstrated that pH of 6, temperature of 300C and olive oil substrate concentration of 1% are significant for optimal production and activity