Lactase intoduction properties , producion and purification of lactase.pptx

Lactase is an enzyme found in the small intestine of mammals. It breaks down lactose (milk sugar) into glucose and galactose. Abundant during infancy, it aids in milk digestion

1. Lactase Submitted by : Piyush Kumar Pandey

2. Introduction Lactase-phlorizin hydrolase, or LPH. Part of the β-galactosidase family of enzymes. It is a glycoside hydrolase involved in the hydrolysis of the disaccharide lactose.

3. Properties The optimum pH for lactose hydrolysis is 6.5. Heating lactase for 1 min results in 97% inactivation at 60 C and complete inactivation at 70 C. Some inactivation occurs at 40 C over 1-h incubation.

4. Production of Lactase Produced by cells known as enterocytes that line the intestinal walls and form the brush border. The natural source of lactase: lactase ( β- galactoside hydrolase; E C3.2 1. 23), a lactose hydrolase, is mainly found in young animal gut, plants, fungi, yeasts and bacteria. Many microorganisms can produce lactase, bacteria in lactic acid bacteria, bud bacillus, Escherichia coli, Lactobacillus oleracea, etc.; Fungi are Aspergillus niger, Aspergillus sphaericus; Yeasts have crisp Kluyveromyces, Lactic acid Kluyveromyces, lactic acid yeast, etc

5. Purification of lactase The cells were separated by centrifugation and lysed using homogenization at 2000 psig . The supernatant after centrifugation was used for purification. This supernatant was concentrated approx. five times by ultrafiltration utilizing polysulfone membrane (nominal molecular weight cutoff [NMWC]—100 kDa ). L. acidophilus15 isolated in the laboratory was used for lactase production.

6. Industrial application Lactases find their applications in three areas: Milk: as a ‘predigester’ for people with milk intolerance problems, Milk destined for cheese and yogurt making, whey or lactose: for the production of sweeteners and hydrolysed whey syrups. Medical use: Supplements to prevent bloating, diarrhea, and gas of lactose intolerance.

7. Mechanism It breaks down lactose into glucose and galactose. Glucose and Galactose are linked via β -1,4 bond. Also has the role of galactosyl transfer.

8. Importance of Lactase It helps to digest Lactose. Catalyses the conversion of Phlorizin to Phloretin . Lactose indigestion can cause nausea, abdominal cramps etc.(due to fermentation by bacteria)

9. References Wikipedia Mahalakshmi, K., and Kiran, H. (2013) Fermentative Production of Lactase from Lactobacillus amylophilus GV6. Journal of Scientific & Industrial Research, 73(7), 548-552. Domingues , L., Onnela , M. L., and Teixeira, J. A. (2000) Con- Struction of Aflocculent Brewer’s Yeast Strain Secreting Aspergillus Niger β- galactosidase. Applied Microbiology and Biotechnology, 54( 1) , 97-103. Nevalainen , K.M.H. Induction, isolation, and characterization of Aspergillus niger mutant strains producing elevated levels of β- galactosidase. Appl. Environ. Microbiol . 1981, 41, 593–6.