Hasan Saba, Ahmad Anis, Purwar Abhinav, Khan Nausheen, Kundan Rishi, Gupta Garima
Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus -226010, India.
Bioinformation. 2013;9(5):238-42. doi: 10.6026/97320630009238. Epub 2013 Mar 2.
This study investigates the mechanisms as well as strategies for purification and characterization of potential enzymes involved in pathogenesis of entomopathogenic fungi. The test strain of Verticillium lecanii that was screened, during the present investigation, proved to be an efficient producer of protein and polysaccharide degrading enzymes (amylase, protease, and lipase), hence indicating versatility in biochemical mechanisms. Halo zones produced colony growth of V. lecanii on agar confirmed activity of protease, amylase and lipase enzyme by the V. lecanii isolate. Enzymatic Index (EI) observed were: Protease - 2.195, Amylase- 2.196, Lipase- 2.147. Spectrophotometric analysis of enzymatic activity of V.lecanii at five different pH - 3, 5, 7, 9, 11 revealed that highest proteolytic activity of the V. lecanii isolate was reported at pH 7 and 9 whereas proteolytic activity was minimum at acidic pH 3. Maximum amylolytic activity of V. lecanii on the 7(th) day of inoculation was at pH 3 i.e. in an acidic environment in contrast to neutral pH 7. Maximum lipolytic activity of V. lecanii was found at pH 7. Since enzyme production in entomopathogenic fungi is specific and forms an important criterion for successful development as well as improvement of mycoinsecticides, hence a significant conclusion from the present analysis is the degree of variation in secretion of enzymes in test strain of Verticillium lecanii.
本研究调查了参与昆虫病原真菌致病过程的潜在酶的纯化和表征机制及策略。在本次调查中筛选出的蜡蚧轮枝菌测试菌株被证明是蛋白质和多糖降解酶（淀粉酶、蛋白酶和脂肪酶）的高效生产者，因此表明其生化机制具有多样性。蜡蚧轮枝菌在琼脂上产生的晕圈证实了该分离株的蛋白酶、淀粉酶和脂肪酶的活性。观察到的酶活性指数（EI）分别为：蛋白酶 - 2.195、淀粉酶 - 2.196、脂肪酶 - 2.147。对蜡蚧轮枝菌在五个不同pH值（3、5、7、9、11）下的酶活性进行分光光度分析，结果显示，蜡蚧轮枝菌分离株的最高蛋白水解活性出现在pH值为7和9时，而在酸性pH值3时蛋白水解活性最低。接种第7天时，蜡蚧轮枝菌在pH值3（即酸性环境）下的淀粉水解活性最高，而在中性pH值7时则相反。蜡蚧轮枝菌的最大脂肪水解活性出现在pH值7时。由于昆虫病原真菌中的酶产生具有特异性，并且是成功开发以及改进杀真菌剂的重要标准，因此本次分析的一个重要结论是蜡蚧轮枝菌测试菌株中酶分泌的变化程度。
