PRODUCTION AND CHARACTERISATION OF L-ASPARAGINASE FROM Priestia megaterium GAFA

Abstract

L-asparaginase is an enzyme used to treat acute lymphoblastic leukaemia due to its ability to break down external L-asparagine necessary for the growth of cancer cells. This work investigated the optimisation of L-asparaginase production and the effect of various factors on the activities of the produced enzyme. An L-asparaginase-producing bacterium collected from the Department of Microbiology and Biotechnology Laboratory was identified using 16S rRNA. The production of L-asparaginase was optimised using Response Surface Methodology (RSM), and the experimental design was validated. The effect of environmental factors on L-asparaginase was determined. The L-asparagine-producing bacterium was identified as Priestia megaterium GAFA with an accession number PP390497. Optimal production (10594.1 U/mL) was validated using glucose as a carbon source, L-asparaginase only as a nitrogen source, fermented at pH 7.76 for 73 hours with an inoculum load of 7.7%. The Ca²⁺ ion significantly increased L-asparaginase activity by 76% compared with the control at p<0.05. The enzyme was active over a wide pH range (4–8), with maximum activity at pH 6.0. The highest activity was observed at 60 °C after 1 hour of incubation. The production of L-asparaginase by Priestia megaterium GAFA was optimised, and environmental factors influenced its activity.