Screening and optimization of L-Asparaginase and L-Glutaminbase Production by some filamentous fungi.

Abstract

Microbial L-asparaginases and L-glutaminases have received significant attention recently owing to their potential applications. The current work details the screening of different filamentous fungal strains for L-asparaginase and L-glutaminase production. During screening program, Peni-cillium brevicompactum NRC 829 showed the highest L-asparaginase and L-glutaminase (activity) production levels. The results also revealed that L-asparaginase and L-glutaminase are true intracellular enzymes. The culture conditions and nutritional requirements affecting biosyn-thesis of both amidases were optimized by varying initial pH, temperature, incubation period, as well as carbon and nitrogen sources. In addition, the effect of various concentrations of sodium chloride and different organic acids on enzymes`enzymes`production was studied. Glucose and NaNO 3 were found to be the best carbon and nitrogen sources for enzymes production with optimum initial pH value at 6.0. Incubation was maximal under static conditions at 28 ºC for 4 days. The values of glucose, NaNO 3 , KH 2 PO 4 and NaCl concentrations were investigated to obtain the maximum enzyme activities. The highest specific activities for both amidases were determined and found to be 3.74 and 5.21 IU/mg protein for L-asparaginase and L-glutaminase, respectively.