Pectinase enzyme:
- Pectinase is the collective term for row of enzyme that are able to breakdown or transform pectins.
- Pectinase is a general form for enzymes such as pectolyase, pectozyme, polygalacturonase etc. commonly referred as pectic enzymes.
- These enzymes breakdown pectin, a polysaccharide that is found in the cell wall of plants.
- The basic structure of pectin is
-1,4-linked galacturonic acid with upto 95% of its carboxyl groups, esterified with methanol.
- Pectinases are classified according to their point of attack on the pectin molecule.
- The methyl ester is split by pectin esterase and glycosidic bonds of pectin chain are split by hydrolysis with endo-polygalacturonase or exo-polygalacturonase.
Pectinase production Microorganisms
- Produced by various bacteria and fungi although commercial microbial pectinase production utilizes spp. of Pencillium and Aspergillus, Aspergillus niger, A. japonicum, B. subtilis, Penicillium italicum, are common pectinase producers.
Industrial Production process:
- Solid or submerged fermentation process are used.
- Substrates: wheat bran, rice bran, potato starch, rice husk, 0.1% NH4NO3, NH4H2PO4, MgSO4
- Enhancer: 2% sucrose and 2% pectin
- Inoculum: spore of A. niger (107 spores per gram of dry substrate)
- Fermentation time: 60-80hrs
- pH: 3-4
- Temperature: 37oC
- Aeration: 0.2-1 vvm
- Purification and extraction:
- Pectinase can be extracted from the cell and the medium so can be recovered from both sources.
- In the process of harvesting, the mycelium is filtered or centrifuged à dried à grind à pectinase extracted with water à Recover aqueous portion is concentrated by evaporation to yield pectinase concentrate.
- As an alternate recovery procedure, pectinase can be precipitated from aqueous solution by the addition of cold acetone, ethanol, isopropanol or ammonium sulphate.
Applications of Pectinase:
- In the preparation of fruit and vegetable juices as it helps the degradation of plant materials and speeding up the extraction of fruits and vegetable juice.
- Used in brewing, the function of pectinase in brewing is two folds
- i. first, it helps the breakdown of plants (fruit) material and so help the extraction of flavours from the mash.
- ii. the presence of pectin in finished wine, causes haze, pectinase is used to break down this haze and clear the wine.
- In the manufacture of concentrates made from fruits or vegetable such as in case of tomatoes, carrots etc.
- In the extraction of pigments, food coloring from plant based raw materials.
- In the industrial manufacture of feeds.
- Used in textile industries, coffee and tea fermentation, vegetable oil extraction and treatment of paper pulp.
- Used for retting.