Alpha-Amylase is one of the most widely used enzymes in the starch industry. However, industrial application of soluble Alpha-Amylase is hampered by changes in pH and temperature (adverse effects on enzyme stability) and activity loss, leading to higher costs. Immobilization of AlphaAmylase is an efficient strategy to reduce the enzyme losing and subsequently reduces costs in this regard. Alpha-Amylases are immobilized by adsorption, entrapment, covalent attachment, and cross-linking. A barrier in Alpha-Amylase immobilization is the large size of its substrate, namely amylose and amylopectin. Most of these immobilization methods decrease the affinity of the enzyme for its substrate as well as the maximum rate of reaction (Vmax). This review aims to study different aspects of Alpha-Amylase including enzyme activity, applications, structure, starch, immobilization methods, and immobilization’, s obstacles to improve Alpha-Amylase efficiency in the industry and also lowering the costs related to providing this enzyme.

Alpha-Amylase reputes for starch modification by breaking of 1-4 glycosidic bands and is widely applied in different industrial sectors. Microorganisms express unique Alpha-Amylases with thermostable and halotolerant characteristics dependent on the microorganism’ s intrinsic features. Likewise, genetic engineering methods are applied to produce enzymes with higher stability in contrast to wild types. As there are widespread application of α-Amylase in industry, optimization methods like RSM are used to improve the production of the enzyme ex vivo. This study aimed to review the latest researches on the production improvement and stability of α-Amylase.

Aim: The aim of this study is to demonstrate the relation between the expression of liver Alpha-Amylase and obesity. Background: Alpha-Amylase catalyses the hydrolysis of 1, 4-Alpha-glucosidic linkages in polysaccharides and has three main subtypes, including: salivary, pancreatic, and hepatic. Hepatic Alpha-Amylase is involved in glycogen metabolism, and has a role in obesity and its management. In this study, we aimed to analyze the expression of liver Alpha-Amylase in overweight and obese mouse. Material and methods: In this study, NMRI male mice were randomly divided into two groups. The sample group (obese) took a high-fat and carbohydrate diet, while the control group (normal) took a laboratory pellet chow for eight weeks. During this period, their weight was measured. After eight weeks, liver hepatocytes were isolated using an enzymatic digestion method. Immunocytochemistry (ICC) and flow cytometry analysis were performed to measure Alpha Amylase protein expression in mouse liver hepatocyte cells. Results: A significant difference in the body weight was observed between the two groups (p<0. 05). The qualitative protein expression of liver Alpha-Amylase was found to be higher in the obese group in both tests (immunocytochemistry and flow cytometry). Animals from the test group presented higher Alpha-Amylase expression, which suggests that this hepatic protein may constitute a potential indicator of susceptibility for fat tissue accumulation and obesity. The present data demonstrates an increased expression of liver Amylase in obese mice. Conclusion: These results suggest that liver Amylase secretion might be useful for predicting susceptibility to obesity induced by consumption of a high-fat and carbohydrate diet.

Alpha-Amylases are starch-degrading enzymes which catalyze the hydrolysis of internal a-1, 4-O-glycosidic bonds in polysaccharides. These enzymes have many applications in food, paper, textile and pharmaceutical industries. About 30 % of world enzyme production market is provided by this enzyme. Alpha Amylases are produced by plants, animals and microorganisms. However, microbial sources are the most preferred one for large scale production. Among microorganisms, Alpha-Amylase is mainly derived from Bacillus genus for commercial applications. Therefore, in this study, 13 different strains of Bacillus genus were tested for their ability to hydrolyze and consume starch. Comparative studies were performed on the strains which were capable to consume starch. The curve of starch consumption by applying logul's solution was depicted for strains. The enzymes activity was assayed by using DNS (3, 5-dinitrosalicylic acid) at various times and temperatures. The best strain according to the enzymatic features was selected. Enzymatic extract was achieved by centrifugation. As Alpha-Amylase was precipitated by ammonium sulphate, desalting process was performed by dialysis. Then zymography and determination of molecular weight for Alpha-Amylase were performed. The best strain regard to enzymatic features was Bacillus amyloliquefaciens. Maximum production of this enzyme was after 36 h. The enzyme activity was at the highest level at 70oC. Molecular weight of the enzyme was about 55KD. In conclusion, the selected strain can be an appropriate candidate for industrial production of Alpha-Amylase.

Background: One of the therapeutic approaches to lower postprandial blood glucose is to inhibition breakdown of starch by inhibiting carbohydrate hydrolysis enzymes. Alpha-Amylase catalyzes the hydrolysis of a- (1, 4) -D-glycosidic linkages of starch and other glucose polymers. Inhibitors of this enzyme could be used in the treatment of diabetes.Objectives: Based on this purpose we examined the effect of curcumin on Alpha Amylase and its IC50 and Ki.Materials and Methods: In this experimental study, 60 rats were divided into two major groups, normal and diabetic, and each was subsequently divided into five subgroups. One of them as control group that received grape seed oil and four of them as experimental groups that received curcumin at 10, 20, 40 and 80 mg/kg (each group include six rats). Blood glucose levels were measured every three days. Serum insulin levels were measured three times, in the first day, middle and end of the experimental period. The activity of serum Alpha Amylase was measured in the end of experimental period.Results: The results showed that curcumin is a competitive inhibitor for Alpha Amylase with IC50=51.32 mMand Ki=20.17 mM. In both diabetic and normal groups in all doses nearly dose dependent manner reduced blood glucose and insulin levels. In both diabetic and normal groups decreased levels of serum Alpha Amylase activity.Conclusions: It may be concluded that curcumin is a potent inhibitor of Alpha Amylase and has beneficial effects in the treatment of overweight and diabetes.

Introduction: Amylases are used in various industries, mainly, starch processing that hydrolyze polysaccharides. Insoluble and solid supports are noteworthy in immobilization of enzymes for industry because of increasing enzyme stability. In this study, immobilization of Alpha Amylase in electrospun polyethersulfone (PES) nanofibers was studied. Materials and Methods: Covalent immobilization of the enzyme was done through the carboxyl groups made by oxygen plasma treatment and 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as a carboxyl group activator agent. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) and contact angle analysis proved enzyme immobilization. The optimum conditions determined and the catalytic parameters of immobilized enzyme were calculated. Results: The results of this investigation showed that the optimum pH of immobilized enzyme was displaced toward acidic region by 1 unit. Comparison of the optimum temperature for immobilized and free Amylase revealed 10° C increasing for the immobilized enzyme. Furthermore, the kinetic parameters, Vmax and Km for the immobilized enzyme were the same and higher than those of free ones, respectively. Storage stability of the immobilized Amylase was obviously improved. Conclusions: The results illustrated that nanofibrous supported Alpha Amylase is a new and suitable matrix for industrial applications.