Amylases are enzymes that break down starch or glycogen.
Amylases are produced by a variety of living organisms, ranging from bacteria to plants and humans. Bacteria and fungi secrete amylases to the outside of their cells to carry out extracellular digestion. When they have broken down the insoluble starch, the soluble end products such as (glucose or maltose) are absorbed into their cells.
Amylases are classified based on how they break down starch molecules
i. α-amylase (alpha-amylase) - Reduces the viscosity of starch by breaking down the bonds at random, therefore producing varied sized chains of glucose ii. ß-amylase (Beta-amylase) - Breaks the glucose-glucose bonds down by removing two glucose units at a time, thereby producing maltose iii. Amyloglucosidase (AMG) - Breaks successive bonds from the non-reducing end of the straight chain, producing glucose
Many microbial amylases usually contain a mixture of these amylases.
Why bother about amylases?
Humans exploit microbial amylases for the following purposes:
1. High Fructose Corn syrup preparation
2. Additives to detergents for removing stains
3. Saccharification of starch for alcohol production
4. Brewing
What organisms are responsible for amylase production?
Although many microorganisms produce this enzyme, the ones most commonly used for their industrial production are Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquifaciens and
Aspergillus niger
General Lab Requirements:
• Autoclave or pressure cooker
• Hot Plate or Microwave oven
• Nutrient Agar powder
• Potato Dextrose Agar powder
• Soluble starch
• Weighing scales
• Shaker
• Spectrophotometer or colorimeter
• Water bath (Temperature controlled)
Materials per group of 4 students
• Hand trowel or disposable spoons
• Sterile pipettes (One each of 10 mL, 5 mL and 1 mL)
• Pipette pumps
• Six bottles of sterile water, containing 90 mL each
• Sterile Glass Petri dishes or Pre-sterilized