Abstract

Marine diversity is clearly considered an interest and most reliable source for the marine microbial community. Accordingly, the synthesis of L-asparaginase was obtained from the natural source of marine actinomycetes. The marine sediment samples were collected from the Gulf of Mannar coastal region, Kayalpatinam, located at Tuticorin district, Tamilnadu, India. A total of 100 marine actinomycetes strains were isolated, among them, 10 isolates belonged to Streptomyces sp. All the Streptomyces strains were screened for L-asparaginase production. Streptomyces sp KPMS7 was showed large pink coloration on L-asparaginase production medium. Based on morphological, biochemical and 16S rRNA sequence studies, the strain was identified as Streptomyces antibioticus KPMS7 and submitted in GenBank with the accession number MH819507. The strain was further studied for production and characterizations of L-asparaginase enzyme carried out by basal medium supplemented with carbon and nitrogen sources. The maximum growth rate was observed in glucose and yeast extract was effectively used as a substrate for L-asparaginase by submerged fermentation. The maximum enzyme activities were obtained in 172 h, pH 7 and temperature 37° respectively. The enzyme was partially purified by ammonium sulphate precipitation and showed a final specific activity of 71.92 IU/mg with 100 % yield was carried out by crude extract enzyme. In Sodium dodecyl-sulfate polyacrylamide gel electrophoresis analysis revealed that the molecular weight of partially purified L-asparaginase was 116 KDa. The finding concludes that the marine isolate Streptomyces antibioticus KPMS7 pointed out a promising novel source for L-asparaginase synthesis used in anticancer therapy.