Pectinases are enzymes produced by microorganisms like fungi and bacteria that break down pectin, a polysaccharide found in plant cell walls. Pectinases include pectolyase, pectozyme, and polygalacturonase. They are used in food processing to extract juices from fruits and help with winemaking. Pectinases are also used for retting plant fibers, oil extraction, improving food textures, and treating wastewater. Factors like pH, temperature, nitrogen source, and carbon source affect microbial pectinase production.
2. Introduction-
•Pectinase is an enzyme that breaks down pectin, a polysaccharide found
in plant cell walls.
•It is widely distributed in higher plants and microorganisms, and also
found in some protozoa and insects. In microorganisms, bacteria,
actinomycetes, yeasts, and molds can synthesize and metabolize
pectinase. Eg. Aspergillus and Penicillium Sclerotium rolfsii, Rhizoctonia
solani, Mucor pusilus, Mucor mucedo, Cloctridium
thermosaccharolyticum, Rhizopus stolonifer, Aureobasiduim
pullulans, Neurospora rassa, Sporotrichum thermophile, etc. are used in
production of pectin.
•They include pectolyase, pectozyme, and polygalacturonase.
•Pectin is the jelly-like matrix which helps cement plant cells together
and in which other cell wall components, such as cellulose fibrils, are
embedded.
• The fungus produces these enzymes to break down the middle
lamella in plants so that it can extract nutrients from the plant tissues
and insert fungal hyphae.eg Aspergillus niger.
3. •Pectinase comprises a heterogeneous group of enzymes that
catalyze the breakdown of pectin-containing substrates.
•The enzyme pectinase lowers the activation energy, and
catalyzes the reaction.
•Pectin esterase catalysis the de-esterification of the methoxy
group of pectin, forming pectic acid.
•Source of energy for growth and as carbon for synthesis of
cell biomass and other products are agricultural/ agro-
industrial wastes eg. sugar cane bagasse, oranges, rice,
banana and coffee.
4. Structure-
Pectin comprises of D-galacturonic acid occurred in α-1,4
chain, naturally esterifies with methoxy groups and natural
sugars occupy the side chains.
Types-
1.Protopectinase-It can promote the dissolution of pectin.
According to its catalytic mechanism it is divided into two
types: Type A pectinase and Type B pectinase. The former
mainly acts on the inner polygalacturonic acid region of
protopectin. The latter mainly acts on the outer polysaccharide
chains of the galacturonic acid chains and cell wall
components.
5. 2.Polygalacturonase- It promotes the hydrolysis of galacturonic acid
chain under water environment. It is divided into two types: one is fungal
exogalacturonase, its final product is monomeric galacturonic acid; the
other is bacterial exogalacturonase, its final product is a dimeric
galacturonic acid.
3.Penctin lyase (PL)-It cleaves pectic polymers by trans-elimination.
can be divided into endogalacturonase (EndoPGL), exogalacturonase
(ExoPGL), endopolymethylgalacturonase (EndoPMGL), and
exopolymethylgalacturonase (ExoPMGL).
4. Pectinesterase (PE)- can remove the methoxy group and promote the
demethylation of pectin.
6. Solid State Fermentation (SSF) and Submerged
Fermentation (SmF)-
Solid state fermentation- Solid State Fermentation (SSF) is a
microbial involved process which takes place under minute
moist conditions or in the complete absence of free-flowing
water contents in the growth/fermentation media. It takes
place with Aspergillus niger using sugar beet pulp as carbon
source and the wastewater from monosodium glutamate
production as nitrogen and water source. Aspergillus oryzae
was cultivated in a pilotscale packed-bed bioreactor containing
citrus pulp and sugarcane bagasse. Pectinase yields of 33-41 U
g-1 were obtained. Banana peel can also be used as substrate.
Temperature of incubation were 8.07 %, 65.82 h and 32.37 °C
respectively.
submerged fermentation (SmF) the nutrients and
microorganisms are both submerged in water.
7.
8. Factors affecting microbial pectinases production-
1. pH-3 -9.
2. Time-varies from 1 to 6 days.
3. Nitrogen source-ammonium phosphate and ammonium
sulphate, ammonium salts, ammonium nitrate, ammonium
chloride , glycine, urea.
4. Carbon source-glucose, sucrose
5.Temparature -45 to 55 °C.
6. Molecular weight- 20kD- 60kD,
9. Uses-
1. It is used in processes involving the degradation of plant
materials, such as speeding up the extraction of fruit
juice from fruit. eg. apples and sapota.
2.In wine production, in brewing, first it helps break down
the plant (typically fruit) material and so helps the extraction
of flavours from the mash. Secondly the presence of pectin in
finished wine causes a haze or slight cloudiness. Pectinase is
used to break this down and so clear the wine.
3. It is used for retting. Addition of chelating agents or pre-
treatment of the plant material with acid enhance the effect of
the enzyme.
4. Pectinases are widely used in the food industry to improve
the cloud stability of fruit and vegetable nectars, for
production and clarification of fruit juices and for haze
removal from wines.
10. 5.Oil extraction, removal of citric fruit peels, and degumming
fibres.
6. Pectinase usage accelerates tea fermentation and also
destroys the foam forming property of instant tea powders by
destroying pectins.
7. They are also used in coffee fermentation to remove
mucilaginous coat from coffee beans.
8.Animal feed industry.
9.Waste water treatment.
10.Textile industry.
11.Modifying pertinacious material.
12.Protoplast fusion technology.
13.Scouring and bleaching of fabric.
14. Purification of plant viruses.