Bioprocess technology Strategies, Production and Purification of Amylases: An overview

Abstract

The Present paper deals with bioprocess strategies involved in the production of Amylases from different microbial sources. Amylases purification and different sources sub categories of amylase production discussed in detailed .The paper also deals with Glucoamylase, Molecular Biology of Amylases , and application of commercially available enzymes. Amylases are among the most important enzymes and are of great significance in present-day biotechnology. Although they can be derived from several sources, such as plants, animals and microorganisms, the enzymes from microbial sources generally meet industrial demands. Microbial amylases could be potentially useful in the pharmaceutical and fine-chemical industries if enzymes with suitable properties could be prepared. Interestingly, the first enzymes produced industrially were an amylase from a fungal source in 1894, which was used as a pharmaceutical aid for the treatment of digestive disorders [1]. With the advent of new frontiers in biotechnology, the spectrum of amylase application has widened in many other fields, such as clinical, medicinal and analytical chemistries, as well as their widespread application in starch analytical chemistries, as well as their widespread application in starch saccharification and in the textile, food ,brewing and distilling industries. Some of the applications of commercial available enzymes available enzymes are summarized in Table1. Amylases have most widely been reported to occur in microorganisms, although they are also found in plants and animals. Two major classes of amylases have been identified in microorganisms, namely ? -Amylase and Glucoamylase. In addition, ? -amylase and, which is generally of plant origin, has also been reported from a few microbial sources. ? -Amylases (endo-1,4-?--D-glucan glucohydrolase,EC 3.2.1.1) are extra cellular enzymes that randomly cleave the 1,4? -D-glucosidic linkages between adjacent glucose units in the linear amylase chain. These are endozymes that split the substrate in the interior of the molecules and are classified according to their action and properties. For examples, amylases that produce free sugars are termed ‘saccharogenic' and those that liquefy starch without producing free sugars are known as ‘starch-liquefying' . ? Amylases (?-1,4-glucan maltohydrolase,EC 3.2.1.2) is usually of plant origin, but a few microbial strains are also known to produce it. It is an exoacting enzymes that cleaves non-reducing chain ends of amylase, amylopectin and glycogen molecules. It hydrolyses alternate glycosidic linkages, yielding glycosidc linkages maltose (? meric form).Since ? amylase is unable to by pass -1,6-glycosidic ? linkages in amylopectin, it results in incomplete degradation of the molecule, yielding 50-60% maltose and limit dextrin. Glucoamylase (synonym amyloglucosidasse, ‘glucanogenic enzymes','starch glucogenase' and ‘Y-amylase'; exo-1,4? D-glucan glucano-hydrolase,EC 3.2.1.3) hydrolyses single glucose units from the non-reducing ends of amylase and amylopectin in a stepwise manner. Unlike ? amylase, most glucoamylopectin, although at a lower rate than 1,4? linkages. Thus glucose, maltose and limit dextrins are the end products of glucoamylase action. Some of the properties of amylases are summarized in Table2.