Amylase

About: Amylase is a research topic. Over the lifetime, 14164 publications have been published within this topic receiving 296069 citations.

Biocatalysis for the Production of Industrial Products and Functional Foods from Rice and Other Agricultural Produce

Abstract: Many industrial products and functional foods can be obtained from cheap and renewable raw agricultural materials. For example, starch can be converted to bioethanol as biofuel to reduce the current demand for petroleum or fossil fuel energy. On the other hand, starch can also be converted to useful functional ingredients, such as high fructose and high maltose syrups, wine, glucose, and trehalose. The conversion process involves fermentation by microorganisms and use of biocatalysts such as hydrolases of the amylase superfamily. Amylases catalyze the process of liquefaction and saccharification of starch. It is possible to perform complete hydrolysis of starch by using the fusion product of both linear and debranching thermostable enzymes. This will result in saving energy otherwise needed for cooling before the next enzyme can act on the substrate, if a sequential process is utilized. Recombinant enzyme technology, protein engineering, and enzyme immobilization are powerful tools available to enhance the activity of enzymes, lower the cost of enzyme through large scale production in a heterologous host, increase their thermostability, improve pH stability, enhance their productivity, and hence making it competitive with the chemical processes involved in starch hydrolysis and conversions. This review emphasizes the potential of using biocatalysis for the production of useful industrial products and functional foods from cheap agricultural produce and transgenic plants. Rice was selected as a typical example to illustrate many applications of biocatalysis in converting low-value agricultural produce to high-value commercial food and industrial products. The greatest advantages of using enzymes for food processing and for industrial production of biobased products are their environmental friendliness and consumer acceptance as being a natural process.

Continuous culture studies on the biosynthesis of alkaline protease, neutral protease and -amylase by Bacillus subtilis NRRL-B3411.

Abstract: SUMMARY: The amounts of three catabolite repressible enzymes, alkaline protease, neutral protease and α-amylase, produced by Bacillus subtilis NRRL-B3411 growing in a chemostat, depended on the growth-limiting substrate. Limiting growth with glucose was advantageous for α-amylase synthesis while nitrogen-limited growth was advantageous for synthesis of the two proteases. Under the conditions used, continuous cultures were unsuitable for large-scale production of the three enzymes since spontaneous mutations to less productive strains occurred in the long term.

Inhibition of serum and urine amylase activity in pancreatitis with hyperlipemia.

Abstract: In 6 of 7 patients with acute pancreatitis and hyperlipemia, inhibition of serum amylase activity was detected by dilution of the serum before assaying for amylase and by correcting for tthe dilution factor. In 4 patients the inhibition phenomenon disappeared within the first few days of hospitalization as the elevated serum triglycerides fell. However, in 2 others there was no relation between triglyceride level and amylase inhibition. Removal of the excess serum lipids by ultracentrifugation did not eliminate the inhibition of amylase activity. Inhibition of amylase activity also occurred in the urine of these patients. No amylase inhibition was demonstrable in lipemic serum from patients without pancreatitis or in pancreatitis serum to which excess lipids were added. The data suggest the presence of a circulating inhibitor of amylase, distinct from the elevated serum lipids, in the serum and urine of patients with acute pancreatitis associated with hyperlipemia. The diagnosis of acute pancreatitis in the patient with abdominal pain and lactescent serum can be facilitated by correcting the serum amylase activity by dilution.

Food grade starch resistant to α-amylase and method of preparing the same

Abstract: Chemically modified RS 4 starches are provided which have a high degree of resistance to α-amylase digestion and can serve as low calorie food additives in products such as breads or crackers as a source of dietary fiber. The starches of the invention can be prepared from any type of starting starch (e.g., wheat, corn, oat, rice, tapioca, mung bean, potato or high amylose starches) and are preferably formed as phosphorylated distarch phosphodiesters. The preferred phosphorylating agent is a mixture of sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) in the presence of sodium chloride or sulfate. The starches are advantageously prepared in an aqueous slurry reaction at basic pH and moderate heating.