A novel L‐asparaginase from the symbiotic Enterobacter aerogenes isolated from Eucheuma sp.

Abstract

This study was aimed to purify and characterize the enzyme L-asparaginase from endophytic microorganisms of Eucheuma sp. in Puntondo Island, South Sulawesi, Indonesia. Research stages were ammonium sulfate precipitation, dialysis, and Sephadex G-75 gel filtration chromatography and Sephadex CMC-50 ion-exchange chromatography matrices. The result of test activities of ammonium sulfate fraction showed the highest range of 40%-60% the activity value of 6.71 IU/ml. The highest protein content was obtained on a 0%-20% fraction of 2.76 mg/ml. Temperature and pH assessments indicated that L-asparaginase had optimum activity at 37°C and pH 8, respectively. At the stage of dialysis, the highest protein content was 5.17 IU/ml in a 0%-20% fraction, and the highest enzyme activity was 1.23 IU/ml in a 20%-40% fraction. The results of gel filtration chromatography fractions G-75 were F5-F10, with a specific activity of 0.60 U/mg, 2.05 times higher purity level than the crude extract enzyme. The results of CMC-50 ion-exchange chromatography showed that F54 and F55 fractions had a specific activity of 106.97 and 295.38 U/mg, respectively, with a purity level of 366.34 and 1,011.57 times higher than the crude extract enzyme. Novelty impact statementEnterobacter aerogenes strain P5, an endophytic bacterium from Eucheuma sp., can produce pure L-asparaginase enzyme with a high specific activity applied in pharmaceuticals nutraceutical applications.