Production and Optimization of L-Glutaminase from Endophytic Fungi

Abstract

L-Glutaminase can be effectively used for treating leukemia and other tumors. It is also used for the treatment of HIV. Besides its therapeutic purposes, it is well known for use in food and chemical industry as well. Present work mainly focuses on production and optimization of L-glutaminase from selected endophytic fungal strain. Six endophytic fungal strains were screened for L-glutaminase production using modified Czapek Dox's agar containing L-glutamine and phenol red. The plate assay was based on pink colour formation around fungal colony. Four strains found positive for L-glutaminase production were fUliher screened by quantitative analysis and Epicoccum sp. NFWI was found to exhibit the highest activity. This strain was further used to optimize fermentation parameters by shake flask fermentation, such as temperature, pH and incubation time. Results showed that 30°C temperature, pH 6 and 5 days of incubation were found to be optimum for production of L-glutaminase. Nutritional factors were optimized using statistical tool, Plackett-Burman design. Out of eleven nutritional factors nutritional factors potassium chloride, molasses, arginine and L-glutamine were found to be contributing in the increased production of L-glutaminase from Epicoccum sp. NFWl. Further under optimum conditions L-glutaminase production by epicoccum sp. NFWI was carried out. Enzyme was purified by acetone precipitation and 56.24 units/mg of specific activity was recorded in the precipitate.