Optimization of intracellular L-Asparaginase production by Streptomyces paulus CA01 isolated from wheat bran using the response surface methodology

Abstract

This study aimed to enhance the production of the intracellular L-asparaginase bacterial enzyme, which is known to impede the growth of cancer cells, by optimizing the culture conditions. In the present study, we exploited the ability of a new Actinomycete strain isolated from a food byproduct, wheat bran, to produce the desired enzyme. Streptomyces paulus CA01 was identified following morphological, biochemical, and molecular testing, and its total L-asparaginase activity was evaluated using ADS agar. Intracellular L-asparaginase activity was measured on the same medium using the well-diffusion method and was quantified by Nesslerization. A Box-Behnken design was employed to optimize the production of the enzyme by analyzing the effect of three factors: temperature, L-Asparagine concentration and glucose concentration. The ADS base medium, which was previously optimized and consisted of starch, K2HPO4, and MgSO4, was also included in the analysis. The optimal conditions for intracellular L-asparaginase production were temperature of 27.5 °C, L-Asparagine concentration of 1.19%, glucose concentration of 0.26% and ADS base medium composition, with which we achieved an incrase in enzymatic activity from 3.20 IU/mL to 8.39 IU/mL. This study indicates that Algerian wheat bran is a potential source of Streptomyces paulus CA01, which produces the bacterial intracellular L-asparaginase enzyme and also opens up prospects for the exploitation of agricultural by-products as sources of interesting micro-organisms. Despite the complex process of cell lysis required for its production, intracellular L-asparaginase is important and depends on culture conditions, making its optimization and increased yield feasible.