Screening and isolation of medicinally important l-asparaginase enzyme from a newly isolated species

Abstract

The L-Asparaginase activity was determined by detection of ammonia or L-aspartic acid. The assay procedure is based on direct Nesslerization of ammonia. The Nine samples were collected at various places of Andhra Pradesh with a viewto isolate potent L-Asparaginase producing microorganisms.A total of 148 colonies were selected and isolated from all the samples based on Lasparaginase enzyme producing microbial strains were identified by their pink colour zones around the colonies. The selected isolates were transferred onto nutrient agar slants and incubated for 24 h. Out of 148 isolates, 46 were selected based on their macroscopic characters, eliminating those that appeared close to each other. The secondary screening was carried out for detection of L-asparaginase positive cultures.After secondary screening, better enzyme producing isolates (5 numbers) were selected and they are designated as MS-3, MS-6, MS-8, MS-11 and MS-15. Among them, the strain MS-6 showed the maximum enzyme production, hence further studies were focused on this strain. For the identification of the promising isolate MS-6, the preliminary morphological, physiological, biochemical tests, utilization of carbon and nitrogen sources were done in our laboratory. A detailed screening of the literature indicated that our isolate is closely related to B. cereus. Hence, the cultural properties of our isolate were compared with reportedproperties of B. cereus. In view of the general agreement and more similarities and a few differences, our isolate MS-6 can be considered to be as a new strain of cereus.