Soil Actinomycetes as Potential Producers of L-Asparaginase: Qualitative, Quantitative and Fermentation Studies

Abstract : Actinomycetes are a group of filamentous, Gram-positive bacteria widely distributed in soil and recognized as prolific producers of bioactive secondary metabolites, including antibiotics and enzymes of therapeutic importance. Among these, L-asparaginase is a clinically significant enzyme used as an antineoplastic agent in the treatment of acute lymphoblastic leukemia. The enzyme catalyzes the hydrolysis of L-asparagine into L-aspartic acid and ammonia, thereby depriving tumor cells of an essential amino acid required for their growth and survival. Although L-asparaginase derived from Escherichia coli and Erwinia carotovora is commercially available, these bacterial sources often cause hypersensitivity and other side effects. Hence, there is a growing need to explore alternative microbial sources such as actinomycetes, which can produce the enzyme with better therapeutic efficiency and fewer side effects. This study aims to identify potent L-asparaginase-producing actinomycetes and their production under submerged fermentation conditions. The study was designed with four major objectives, to isolate actinomycetes from soil samples, to perform qualitative and quantitative assays for L-asparaginase production, and to evaluate the production of L-asparaginase by submerged fermentation using boiled rice water as the substrate. Soil sample was collected, and actinomycetes were isolated using standard microbiological techniques. The qualitative screening of isolates was carried out using a plate assay method to identify potential L-asparaginase-producing strains based on the formation of color zones. Quantitative estimation of enzyme activity was performed by measuring the amount of ammonia released during enzymatic reaction. For enzyme production, submerged fermentation was employed, utilizing boiled rice water as a nutrient-rich, cost-effective substrate to enhance enzyme yield.