International Centre for Nanobiotechnology, Centre for Marine Science and Technology, Manonmaniam Sundaranar University, Rajakkamangalam 629 502, Kanyakumari District, Tamil Nadu, India.
Department of Biotechnology, Holycross College, Nagercoil, Kanyakumari District, India.
Saudi J Biol Sci. 2014 Jan;21(1):27-34. doi: 10.1016/j.sjbs.2013.04.010. Epub 2013 May 6.
Agro-industrial residues and cow dung were used as the substrate for the production of alkaline protease by Bacillus cereus strain AT. The bacterial strain Bacillus cereus strain AT produced a high level of protease using cow dung substrate (4813 ± 62 U g(-1)). Physiological fermentation factors such as the incubation time (72 h), the pH (9), the moisture content (120%), and the inoculum level (6%) played a vital role in the enzyme bioprocess. The enzyme production improved with the supplementation of maltose and yeast extract as carbon and nitrogen sources, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and zymogram analysis of the purified protease indicated an estimated molecular mass of 46 kDa. The protease enzyme was stable over a temperature range of 40-50 °C and pH 6-9, with maximum activity at 50 °C and pH 8. Among the divalent ions tested, Ca(2+), Na(+) and Mg(2+) showed activities of 107 ± 0.7%, 103.5 ± 1.3%, and 104.6 ± 0.9, respectively. The enzyme showed stability in the presence of surfactants such as sodium dodecyl sulfate and on various commercially available detergents. The crude enzyme effectively de-haired goat hides within 18 h of incubation at 30 °C. The enzymatic properties of this protease suggest its suitable application as an additive in detergent formulation and also in leather processing. Based on the laboratory results, the use of cow dung for producing and extracting enzyme is not cumbersome and is easy to scale up. Considering its cheap cost and availability, cow dung is an ideal substrate for enzyme bioprocess in an industrial point of view.
农业工业残渣和牛粪被用作生产碱性蛋白酶的底物，由蜡状芽孢杆菌菌株 AT 生产。该细菌菌株 AT 使用牛粪底物（4813±62 U g(-1)）产生高水平的蛋白酶。生理发酵因素，如培养时间（72 h）、pH 值（9）、水分含量（120%）和接种水平（6%），在酶生物过程中起着至关重要的作用。酶的产量随着麦芽糖和酵母提取物作为碳源和氮源的补充而提高。SDS-聚丙烯酰胺凝胶电泳和纯化蛋白酶的酶谱分析表明，其估计分子量为 46 kDa。该蛋白酶在 40-50°C 和 pH 6-9 的温度范围内稳定，在 50°C 和 pH 8 时具有最大活性。在测试的二价离子中，Ca(2+)、Na(+) 和 Mg(2+)的活性分别为 107±0.7%、103.5±1.3%和 104.6±0.9%。该酶在表面活性剂如十二烷基硫酸钠和各种市售洗涤剂存在下具有稳定性。粗酶在 30°C 孵育 18 小时内有效地对山羊皮进行脱毛。该蛋白酶的酶学特性表明其适合作为洗涤剂配方中的添加剂，也适合用于皮革加工。基于实验室结果，使用牛粪生产和提取酶并不麻烦，易于扩大规模。考虑到其廉价的成本和可用性，牛粪从工业角度来看是酶生物过程的理想底物。
