Microbial L-asparginases has wide range of applications as therapeutic agents and in industries. In the present study, 57 bacterial isolates from Konark beach, Bhubaneshwar were screened for L-asparginase production and KBI-13 isolate was found to be potential producer strain. KBI-13 was identified as Bacillus subtilis at molecular levels. During production optimization, pH (8.0), temperature (40 ºC), carbon and nitrogen sources (dextrose- 0.5 %; yeast extract 1 %), aeration conditions, metal salts (FeSO₄) and NaCl (4 %) were found to be optimum. The enzyme was produced under optimized conditions and was purified by sephadex G-50 column and the purification was obtained upto 61.54 fold. The activity of enzyme was increased upto pH 8.0 and temperature 40 ºC and its stability was observed upto 16 hrs at 40 ºC temperature and pH 8.0. Pretreatment of 0.5 mM CaCl₂ increased the enzyme activity upto 20 % while, 250 mM concentration of L-aspargine was suitable for optimum activity of enzyme which was further confirmed by values of Vmax (1.25 µM/min) and Km (0.05 mM). The reaction end products did not show any significant change in enzyme activity.

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海洋枯草芽孢杆菌中L-天冬酰胺酶的分离及鉴定

微生物L-天冬酰胺酶作为治疗剂和在工业中具有广泛的应用。在本研究中，从布巴内斯瓦尔的Konark海滩分离了57株细菌，检测L-天冬酰胺酶的产生，发现KBI-13分离株是潜在的生产菌株。在分子水平上，KBI-13被鉴定为枯草芽孢杆菌。在生产优化过程中，pH值（8.0），温度（40ºC），碳和氮源（葡萄糖-0.5％；酵母提取物1％），通气条件，金属盐（FeSO ₄）和NaCl（4％）被发现是最佳的。该酶在优化的条件下产生，并通过sephadex G-50柱纯化，纯化率最高达到61.54倍。在pH 8.0和40ºC的温度下，酶的活性都增加了，在40ºC和pH 8.0的温度下长达16小时观察到了其稳定性。预处理0.5 mM CaCl ₂可使酶活性提高20％，而250 mM浓度的L-天门冬氨酸适合最佳酶活性，这又由Vmax（1.25 µM / min）和Km（0.05 mM）值进一步证实。反应终产物在酶活性上没有显示任何显着变化。