Optimization of growth conditions for purification and production of L-asparaginase by Spirulina maxima

Abstract

L-asparaginase (L-AsnA) is widely distributed among microorganisms and has important applications in medicine and in food technology sectors. Terefore, the ability of the production, purifcation, and characterization of AsnA from Spirulina maxima (SM) were tested. SM cultures grown in Zarrouk medium containing diferent N2 (in NaNO3 form) concentrations (1.25,2.50, and 5.0 g/L) for 18 days contained a signifcant various quantity of dry biomass yields and AsnA enzyme levels. MS L-AsnA activity was found to be directly proportional to the N2 concentration. Te cultures of SM at large scales (300 L medium, 5 g/L N2) showed a high AsnA enzyme activity (898IU), total protein (405 mg/g), specifc enzyme activity (2.21 IU/mg protein), and enzyme yield (51.28 IU/L) compared with those in low N2 cultures. Te partial purifcation of crude MS AsnA enzyme achieved by 80% ammonium sulfate AS precipitated and CM-Sephadex C-200 gel fltration led to increases in the purifcation of enzyme with 5.28 and 10.91 times as great as that in SM crude enzymes. Optimum pH and temperature of purifed AsnA for the hydrolyzate were 8.5 and 37 ± 0.2°C, respectively. To the best of our knowledge, this is the frst report on L-asparaginase production in S. maxima.