Jujjavarapu Satya Eswari, Dhagat Swasti
Department of Biotechnology, National Institute of Technology Raipur, Raipur-492010, India.
Recent Pat Biotechnol. 2019;13(1):4-18. doi: 10.2174/2211550107666180816093436.
Amylase catalyzes the breakdown of long-chain carbohydrates to yield maltotriose, maltose, glucose and dextrin as end products. It is present in mammalian saliva and helps in digestion.
Their applications in biotechnology include starch processing, biofuel, food, paper, textile and detergent industries, bioremediation of environmental pollutants and in clinical and medical applications. The commercial microbial strains for production of α-amylase are Bacillus subtilis, B. licheniformis, B. amyloliquefaciens and Aspergillus oryzae. Industrial production of enzymes requires high productivity and cannot use wild-type strains for enzyme production. The yield of enzyme from bacteria can be increased by varying the physiological and genetic properties of strains.
The genetic properties of a bacterium can be improved by enhancing the expression levels of the gene and secretion of the enzyme outside the cells, thereby improving the productivity by preventing degradation of enzymes. Overall, the strain for specific productivity should have the maximum ability for synthesis and secretion of an enzyme of interest. Genetic manipulation of α-amylase can also be used for the production of enzymes with different properties, for example, by recombinant DNA technology.
This review summarizes different techniques in the production of recombinant α- amylases along with the patents in this arena. The washing out of enzymes in reactions became a limitation in utilization of these enzymes in industries and hence immobilization of these enzymes becomes important. This paper also discusses the immobilization techniques for used α-amylases.
淀粉酶催化长链碳水化合物的分解，最终产生麦芽三糖、麦芽糖、葡萄糖和糊精。它存在于哺乳动物的唾液中，有助于消化。
其在生物技术中的应用包括淀粉加工、生物燃料、食品、造纸、纺织和洗涤剂工业、环境污染物的生物修复以及临床和医学应用。生产α-淀粉酶的商业微生物菌株有枯草芽孢杆菌、地衣芽孢杆菌、解淀粉芽孢杆菌和米曲霉。工业酶生产需要高生产率，不能使用野生型菌株来生产酶。通过改变菌株的生理和遗传特性可以提高细菌产生酶的产量。
通过提高基因的表达水平和酶在细胞外的分泌，可以改善细菌的遗传特性，从而通过防止酶的降解来提高生产率。总体而言，具有特定生产率的菌株应具有合成和分泌目标酶的最大能力。α-淀粉酶的基因操作也可用于生产具有不同特性的酶，例如通过重组DNA技术。
本综述总结了重组α-淀粉酶生产中的不同技术以及该领域的专利。反应中酶的洗脱成为这些酶在工业中应用的一个限制因素，因此这些酶的固定化变得很重要。本文还讨论了所用α-淀粉酶的固定化技术。
