Production of extracellular L- asparaginase by halophilic bacterium vibrio sp

L-Asparaginase is an anti-neoplastic drug used in lymphoblastic leukemia chemotherapy. Nowadays, this enzyme derived from bacterial sources, mostly L-asparaginase II from Escherichia coli and in lesser amount L-asparaginase of Erwinia sp. has medical utilization. The long-term usage of these agents leads to allergic reactions; therefore new L- asparaginase with new immunological characteristics is required. Halophilic bacteria might contain L-asparaginase with novel immunological properties that can be used in hypersensitive patients.
In this study, the production of L-asparaginase by 130 halophilic and halotolerant bacteria isolated from saline environments in Iran was screened. Modified M-9 agar medium was used for qualitative analysis. In the selected strain, growth curve plotting, asparaginase activity assay and analysis for the effect of some factors on the production and enzyme activity were done.
40 strains produced L-asparaginase. Most of L-asparaginase producers were member of genus Halomonas and Marinobacter (21.4%). GBP­x3 is potent bacteria in L-asparaginase production which belonged to Vibrio sp. based on 16S rRNA analysis. Optimized factors for L-asparaginase production were 350C (0.65 IU/ml), pH 8 (0.926 IU/ml) and 2.5% NaCl (0.903 IU/ml). The highest activity of L-asparaginase was in 350C (0.781 IU/ml), pH 8 (0.82 IU/ml) and without NaCl (0.806 IU/ml).
Discussion and The aim of this study was to screen the production of
L-asparaginase through 130 halophilic and halotolerant bacteria which were isolated from saline environments in Iran. The results of this work indicate that the bacterium, Vibrio sp. GBP­x3 displays to be potent for asparaginase production.