This Presentation discusses in detail types of enzymes and how they breakdown polysaccharides.

1. ENZYMES
Breaking Down
POLYSACCHARIDES
Presented by:
Prasanna Bhalerao

2. POLYSACCHARIDES
 Polymeric carbohydrate molecules
 Polysaccharides contain more than ten monosaccharide units.
 Composed of long chains of monosaccharide units bound together by glycosidic linkages
 On hydrolysis give the constituent monosaccharides or oligosaccharides.
 When all the monosaccharides in a polysaccharide are the same type, the polysaccharide is called
a homopolysaccharide or homoglycan, but when more than one type of monosaccharide is present
they are called heteropolysaccharides or heteroglycans.

3. Types
Of
POLYSACCHARIDES
STORAGE
POLYSACCHARIDES
STRUCTURAL
POLYSACCHARIDES
ACIDIC POLYSACCHARIDES
Microbial
polysaccharides
Starch
Glycogen
Chitin
Hemicellulose
Pectin
Cellulose

4. ENZYMES
Enzymes lower activation energy of reactions
Enzyme promotes and
speeds up a chemical
reaction without itself
being altered in the
process.
Naturally occurring
biocatalysts

5.  Composed of long chains of monosaccharide units bound together by glycosidic linkages
 On ENZYMATIC hydrolysis give the constituent monosaccharides or oligosaccharides

6. Breakdown of Storage
Polysaccharides1) STARCH
Starch is basically polymers of the six-carbon sugar D-glucopyranose,
Linear polymer of
starch composed
of α-1,4-linked D-
glucopyranose
molecules. A small
number of α-1,6-
linked branches
may be present
branched, D –
glucopyranose
polymer of starch
containing both α -1,4
and α -1,6 linkages.
The α -1,6 linkage
represents the bond
at the polymeric
branch point
α-1, 6 linkage
α-1, 4 linkages
Reducing
End

7. Enzymes breaking down Starch
Glycosyl hydrolases (GH)
 Alpha Amylase:
 EC 3.2.1.1 (α-1,4-glucanohydrolase)
 Endoenzymes that catalyze the cleavage of α-1,4-glycosidic bonds in the inner part of the amylose or
amylopectin chain.
 The end products of α-amylase action are oligosaccharides, with an α-configuration and varying lengths, and
α-limit dextrins, which are branched oligosaccharides.
 Maltogenic α-amylase:
 EC 3.2.1.133 (glucan 1,4-a-glucanhydrolase)
 Exoenzyme mainly releases maltose from starch
 Maltooligosaccharide producing amylases give rise to maltotetraose or maltohexaose
 Maltooligosaccharide forming amylases (EC 3.2.1.60) :

8.  Pullulanase (EC 3.2.1.41)
 Debranching enzymes
 Hydrolyse α-(1,6)-bonds removing the side-chains from amylopectin
 Type I pullulanases specifically attack α-1,6 linkages, while type II pullulanases (amylopullulanase), Pullulan
Hydrolases Type III are able to hydrolyse α-1,4 linkages ,6-glucosidic bonds in starch and related
polysaccharides
 Isoamylase (EC 3.2.1.68)
 Debranching enzymes
 Hydrolyse α-(1,6)-bonds removing the side-chains from amylopectin
 Glucoamylases (EC. 3.2.1.3)
 Exoglucanases also known as amyloglucosidase, g-amylase.
 Enzymes cleave off terminal 1,4-1inked a-Dglucose residues successively from non-reducing ends of the
chains with the release of b-D-glucose.

9.  Beta-amylase (EC 3.2.1.2,) 1,4-alpha-D-glucan maltohydrolase
 Hydrolysis of (1->4)-alpha-D-glucosidic linkages in polysaccharides so as to remove successive maltose units
from the non-reducing ends of the chain

10. Enzymes that hydrolyse starch to a series of nonreducing cyclic D-glucosyl polymers called CYCLODEXTRINS
e.g. Bacillus macerans amylase (cyclodextrin producing enzyme)
Source
Of amylase
Microbial
Bacterial
Fungal
Plant
Animal
 α-amylase Bacillus licheniformis M27, include two peaks for pH optima at 6.5–7.0 and 8.5–9.0, temperature
optimum at 85–90°C at pH 7.0 and 9.0
 Pullulanase type II from P. woesei is extremely thermostable at 110 °C , has ability to attack both a-1,6 &
a-1,4-glycosidic linkages.
EXTREMOPHILIC MICROBIAL SOURCES
 The thermophilic fungus Thermomyces lanuginosus is an excellent producer of amylase

11. Alpha amylase

13. LIQUEFACTION : the starch suspension’s viscosity is high following gelatinization. α-amylase is used as a
thinning agent, which brings about reduction in viscosity and partial hydrolysis of Starch to maltodextrin.
SACCHARIFICATION : b amylase, pullulanase, isoamylase, glucoamylase break down the maltodextrins
formed during liquefaction into maltoligosaccharides and even in to simpler sugars like maltose, glucose
Liquefaction & Saccharification steps are utilized in
different industries
BAKERY
CONFECTIONARYBREWERYSUGAR
SYRUPS
APPLICATIONS

14. alpha-amylases degrade the damaged starch in wheat flour into small dextrins, thus allowing yeast to work continuously during
dough fermentation, proofing, resulting in improved bread volume and crumb texture. In addition, the small oligosaccharides
and sugars such as glucose and maltose produced by these enzymes enhance the reactions for the browning of the crust and
baked flavour.(Caramelisation, MBR). Certain amylases are able to decrease the firming rate of bread crumb, acting as anti-
staling agents
BREWERY:
Liquefaction and saccharification of corn starch leads to the production of glucose syrup that can then be converted into fructose
syrup by isomerization catalysed by glucose isomerase. The fructose syrup obtained is used as a sweetener, especially in the
beverage industry.
Liquefaction and saccharification of steeped germinated barley grains breaks the starch to dextrins and then to maltose and
other reducing sugars in the mash on which yeasts act to produce alcohol
SUGAR SYRUPS:
CONFECTIONARY
Maltooligomer mix powder obtained by spray drying is highly hygroscopic. Therefore it serves as a moisture regulator of the
food with which it is mixed. Maltooligomer mix taste less sweet that sucrose used as its substitute. It is also used for preventing
crystallization of sucrose.
BAKERY

15. Amylases are used in textile industry for desizing process. Sizing agents like starch are applied to yarn before fabric production
to ensure a fast and secure weaving process. Desizing involves the removal of starch from the fabric which serves as the
strengthening agent to prevent breaking of the thread during weaving.
TEXTILE INDUSTRY
The use of α-amylases in the pulp and paper industry is for the modification of starch of coated paper, i.e. for the production of
low-viscosity, high molecular weight starch .The coating treatment make the surface of paper smooth and strong, to improve the
writing quality of the paper.
These enzymes are used in detergents for laundry and automatic dishwashing to degrade the residues of starchy foods such as
potatoes, gravies, custard, chocolate, etc. to dextrins and other smaller oligosaccharides.
Removal of starch from surfaces is also important in providing a whiteness benefit, since starch can attract many types of
particulate soils.
DETERGENT INDUSTRY
Saccharomyces fibuligera and S. cerevisiae directly convert starch to ethanol through liquefaction and saccharification
followed by fermentation
FUEL ALCOHOL PRODUCTION
PAPER INDUSTRY

16. 2) GLYCOGEN
 Glycogen is a multi-branched polysaccharide of
glucose that serves as a form of energy storage in
animals and fungi.
 The polysaccharide structure represents the main
storage form of glucose in the body.
 In humans, glycogen is made and stored primarily in
the cells of the liver and the muscles, and functions as
the secondary long-term energy storage
 branched biopolymer consisting of linear chains of
glucose residues with further chains branching off every
8 to 12 glucoses or so.
 Glucoses are linked together linearly by α(1→4)
glycosidic bonds from one glucose to the next.
Branches are linked to the chains from which they are
branching off by α(1→6) glycosidic bonds.

17. Glycogen Phosphorylase
It catalyzes phosphorolytic cleavage of the a(1,4)
glycosidic linkages of glycogen, releasing glucose-1-
phosphate as the reaction product. It requires PLP as
cofactor & allosterically inhibited by chloroindole-
carboxamides.
Phosphoglucomutase
It catalyzes the reversible reaction:
Glucose-1-phosphate Glucose-6-phosphate
The liver enzyme Glucose-6-phosphatase catalyzes the
following reaction, essential to the liver's role in
maintaining blood glucose
Glucose-6-phosphate + H2O glucose + Pi
Glucose-6-phosphatase
Enzymes breaking down GLYCOGEN

18. Breakdown of STRUCTURAL Polysaccharides
3) CELLULOSE
Cellulose is an organic compound with the formula
(C6H10O5)n, a polysaccharide consisting of a
linear chain of several hundred to many thousands
of β(1→4) linked D-glucose units
The major component in the rigid cell walls
in plants
most abundant organic polymer on Earth

19. Enzymes breaking down Cellulose
Three general types of cellulases based on the type of reaction catalyzed:
Participates in the hydrolysis of the 1,4-beta-D-glycosidic linkages in cellulose
 Endocellulases (EC 3.2.1.4)
They randomly cleave internal bonds at amorphous sites that create new chain ends
 Exocellulases (EC 3.2.1.91)
Cellobiohydrolases cleave two to four units from the ends of the exposed chains produced by endocellulase, resulting in
tetrasaccharides or disaccharides, such as cellobiose
work processively from the nonreducing end of cellulose chain.I II
work processively from the reducing end of the cellulose
chain

20. Cellobiases (EC 3.2.1.21) or beta-glucosidases hydrolyse the exocellulase product into individual
monosaccharides.
 Cellobiase (EC 3.2.1.2.1)

21. SOURCES

22. BEVERAGE INDUSTRY
 Cellulases is a part of macerating enzymes complex (cellulases, xylanases, and pectinases) for extraction and clarification
of fruit and vegetable juices to increase the yield of juices. They improve cloud stability and texture and decrease viscosity
of the nectars and purees from tropical fruits such as mango, peach, papaya, plum, apricot, and pear and decreases their
viscosity rapidly
 Flavor, and aroma properties of fruits and vegetables can be improved by reducing excessive bitterness of citrus fruits by
infusion of enzymes such as β-glucosidases.
Enzyme mixtures containing pectinases, cellulases, used for improved extraction of olive oil , rapid and intense
disintegration of the cell walls and membranes of the olive fruits, thereby favoring also the passage of noble substances
(particularly the polyphenols and aromatic precursors) into the final product.
Cellulases effectively hydrolyse the anti-nutritional factors and complex cellulose, in the feed materials into easily absorbent
ingredient thus improve animal health and performance
ANIMAL FEED INDUSTRY
The wastes generated from forests, agricultural fields, and agro-industries contain a large amount of unutilized or
underutilized cellulose, causing environmental pollution can be converted by cellulose to useful products
WASTE MANAGEMENT
OIL EXTRACTION

23.  Exogenous cellulase may be a potential means to accelerate straw decomposition and increase soil fertility
 Cellulases participate in degrading the cell wall of plant pathogens and so in controlling the plant disease
AGRICULTURAL INDUSTRIES
use of cellulase disrupts the cell wall of orange peel, sweet potato and carrot, and releases the carotenoids in the
chloroplasts and in cell fluids. These pigments remain in their natural state still bound with proteins. This bonded structure
prevents pigment oxidation whereas solvent extraction dissociates the pigments from the proteins and causes water
insolubility and ease of oxidation.
Cellulase preparations capable of modifying cellulose fibrils can improve color brightness, feel, and dirt removal from the
cotton blend garments. The cellulases are applied to remove these rough protuberances for a smoother, glossier, and
brighter-colored fabric
BIOETHANOL INDUSTRY
Enzymatic saccharification of lignocellulosic materials such as sugarcane bagasse, corncob, rice straw, Prosopis juliflora,
Lantana camara, switch grass, saw dust, and forest residues by cellulases for biofuel production
CAROTENOID EXTRACTION
DETERGENT INDUSTRY

24.  Cellulases have been used for biostoning of jeans and
biopolishing of cellulosic fabrics. During the biostoning
process, cellulases act on fabric and break off the small
fiber ends on the yarn surface, thereby loosening the dye,
which is easily removed by mechanical abrasion in the
wash cycle, leading to less damage of fibers.
 Cellulases can remove these microfibrils which make the
cloth fluffy and dull and restore a smooth surface and
original color to the garments .
 The use of cellulase also helps in softening the garments
and in removal of dirt particles trapped within the
microfibril network.
PULP AND PAPER INDUSTRY
TEXTILE INDUSTRY
 Cellulases used for biomodification of fiber properties
with the aim of improving drainage and beatability in the
paper mills before or after beating of pulp.
 Cellulases have also been reported to enhance the
bleachability of softwood kraft pulp producing a final
brightness score.
 Cellulases are beneficial for deinking of different types of
paper wastes by partial hydrolysis of carbohydrate.
 Cellulases in improving the drainage has also been
pursued by several mills with the objective to increase the
production rate. Enzyme treatments remove some of the
fines or peel off fibrils on the fiber surface and dissolved
and colloidal substances, which often cause severe
drainage problems in paper mills.

25.  Hemicellulose is a complex carbohydrate polymer and makes up 25–30% of total wood dry
weight. It is a polysaccharide with a lower molecular weight than cellulose
Xylan is the main carbohydrate found in hemicellulose found in plant cell walls and some algae.
• It is the second most-abundant polysaccharide in nature
• The primary chain of xylan is composed of 1,4 linked β-D-xylopyranosyl units
• Based on the common substituents found on the backbone, xylans are categorized as linear
Homoxylan, Arabinoxylan, Glucuronoxylan Or Glucuronoarabinoxylan
4) HEMICELLULOSE
 Hemicelluloses include XYLANS, MANNANS, AND GLUCANS
4.1) XYLAN

26. LINEAR HOMOXYLAN
Backbone substituted by glucuronic acid and 4-O-methyl glucuronic acid
• Feruloyl groups are esterified to the O-5 position of the Ara units
in about every 50 units
ARABINOXYLAN :
• Xylose units are substituted with 2, 3 or 2,3-linked arabinose residues
(1-4)-D-xylose linked polymer branched with arabinose
and glucuronic acid.
GLUCURONOXYLAN:
GLUCURONOARABINOXYLAN :

27. Enzymes breaking down XYLAN
Xylanases have been primarily classified as GH 10 and 11

29. GLUCURONOXYLAN (HardWood Xylan)
b xylosidase
xylose

32. BAKERY INDUSTRY
 Xylanase transforms water insoluble hemicellulose into soluble form, which binds water in the dough, therefore
decreasing the dough firmness, increasing volume and creating finer and more uniform crumbs.
 In biscuit-making, xylanase is recommended for making cream crackers lighter and improving the texture, palatability
and uniformity of the wafers.
 Xylanases make the dough more tolerant to different flour quality parameters and variations in processing methods. They
also make the dough soft, reduce the sheeting work requirements and significantly increase the volume of the leavened
pan bread.
 Xylanases, in conjunction with cellulases, amylases and pectinases, lead to an improved yield of juice by means of
liquefaction of fruit and vegetables; stabilization of the fruit pulp; increased recovery of aromas, essential oils, vitamins,
mineral salts, edible dyes, pigments etc., reduction of viscosity, hydrolysis of substances that hinder the physical or
chemical clearing of the juice, or that may cause cloudiness in the concentrate.
 During the manufacture of beer, the cellular wall of the barley is hydrolyzed releasing long chains of arabinoxylans
which increase the beer’s viscosity rendering it “muddy” in appearance.
BREWERY INDUSTRY

33. ANIMAL FEEDSTOCKS
 Addition of Endo-1,4-β-xylanase in animal feed stimulates animal growth rates by improving digestibility and improving
the quality of animal litter.
 Xylanases are used in animal feed along with glucanases, pectinases, cellulases, proteases, amylases, phytase,
galactosidases and lipases. These enzymes break down arabinoxylans in the ingredients of the feed(that makes them
difficult to digest by domestic animals) , reducing the viscosity of the raw material
PHARMACEUTICAL AND CHEMICAL APPLICATIONS
 Xylanases are sometimes added in combination with a complex of enzymes (hemicellulases, proteases and others) as a
dietary supplement or to treat poor digestion.
 Hydrolytic products of xylan, such as β-D-xylopyranosyl residues, can be converted into combustible liquids (ethanol),
solvents and artificial low-calorie sweeteners.
 The first steps are the delignification of hemicellulose material rich in xylan, followed by hydrolysis by xylanases and
hemicellulases, to produce sugars such as β-D- xylopyranosyl units. Then the products are fermented, mainly by yeasts
(Pichia stipitis )to produce xylitol or ethanol.
 Xylitol is a poly- alcohol with a sweetening power comparable to that of sucrose. It is a non-carcinogenic sweetener,
suitable for diabetic and obese individuals.

34. Mannan is one of the important member of the hemicellulose family and can be divided to four subfamilies:
 Linear Mannan, : β-1,4-linked backbone containing mannose
 Glucomannan, Galactomannan, And Galactoglucomanan:
• Combination of glucose and mannose residues (glucomannan) and occasional side chains of a-1,6-linked galactose residues
(galactomannan / galactoglucomann).
• In the backbone, mannose and glucose units can also be acetylated at C-2 or C-3
Endo β-mannanase (EC 3.2.1.78)
• Also known as 1,4-β-D mannan mannanohydrolase belongs to the glycosyl hydrolyase families.
• This enzyme hydrolyses the 1,4 linkage of mannan to produce simple sugar mannose.
• It is involved in hydrolysis of the mannan-rich cell walls of the tomato (Lycopersicon esculentum.) endosperm during
germination and post-germinative seedling growth.
4.2) MANNAN
Enzymes breaking down MANNAN
• β-mannanases from molluscs have been isolated from their digestive tract
• It catalyses the hydrolysis of mannose units from the non-reducing end of mannosides.
Exoacting β-Mannosidase (EC 3.2.1.25; β-1,4-D-mannoside mannohydrolase) :

35. The α-galactosidases remove the α-1,6-linked D-galactopyranosyl substituents attached to the mannan
backbone, whereas acetyl mannan esterases release the acetyl groups from galactoglucomannan

36.  USE IN BIOMEDICALAPPLICATIONS:
 Galactomannans have also significant potential in medical applications such as innate immune system stimulation. On the
other hand, the mannooligosaccharides (MOS) derived from these polysaccharides have also prebiotic activity. They
present anticoagulation and fibrinolytic activity and the MOS may prevent adherence of toxic bacteria to the intestinal
wall, mediated by lectins, thus presenting anti-infectious potential
 Roos et al. synthesized hydrogels from O-acetyl-galactoglucomannan (AcGGM) with encapsulated bovine serum
albumin (BSA), to investigate the influence of substitutions and the feasibility of BSA-release mediated by the addition
of β-mannanase to hydrolyze the hydrogel and it proved successful This is used for developments of AcGGM-based
hydrogels for the application of drug delivery
 BIOBLEACHING OF PULPAND PAPER:
 In the enzymatic treatment of pulp bleaching, β-mannanase and its accessory enzymes are able to cleave the mannan
component in the pulp selectively without affecting cellulose. thus facilitates subsequent removal of lignin.
 Mannanases are useful for reducing viscosity of print paste, thereby facilitating wash out of surplus print paste after
textile printings
 HYDROLYTIC AGENT IN DETERGENT INDUSTRY :
Recently, alkaline mannanases stable in detergents have found application in laundry segments as stain removal boosters
 USE IN HYDROLYSIS OF COFFEE EXTRACT :
 Mannans in the coffee extract are efficiently hydrolyzed by the mannanase, which result in viscosity reduction.
 As a consequence of the above enzymatic action, the coffee bean extracts can be concentrated by evaporation easily

37.  USE IN IMPROVEMENT OF ANIMAL FEEDS :
Incorporation of β-mannanase in the animal diets helps in a number of ways: breakdown of β-mannan in cell wall and
release of encapsulated nutrients, increased villus height in duodenum and jejunum that leads to increase in surface area and
adsorption and decreased digesta viscosity
 Mannanases can play important role as slime control agent in water purification system, vacuum sewer systems, waste
water treatment and cooling water treatment systems.
 A composition comprising mannanase can be used for both, controlling the adhesion of bacteria to a large extent and
also for removing biofilm on surfaces of water bearing systems
The oil and gas industries use enzymatic hydrolysis of galactomannan to enhance the flow of oil and gas in drilling
operations
Mannanases can be used in enzymatic oil extraction of coconut meat as the main components of the structural cell wall of
coconut meats are mannan and galactomanann
 AS SLIME CONTROL AGENTS :
 OTHER USES:

38. 5) PECTIN
 Structural hetero-polysaccharide found in the primary cell walls of terrestrial plants
o Substitutions lead to different types:
 Homogalacturonans are linear chains of α-(1–4)-linked D-galacturonic acid.
 Substituted galacturonans characterized by the presence of saccharide residues
(such as D-xylose)give rise to xylogalacturonan branching from a backbone of
D-galacturonic acid residues
 Rhamnogalacturonan I pectins (RG-I) contain a backbone of the repeating disaccharide: 4)-α-D-galacturonic acid-(1,2)-α-
L-rhamnose-

39. Enzymes breaking down PECTIN
Pectinase or pectinolytic enzymes is a general term for enzymes , which include the following classes :
1) Pectin acetylesterase releases the acetyl residue linked to the
galacturonic acid.
2) Rhamnogalacturonase cuts the bonds between galacturonic
acid and rhamnose in the rhamnogalacturonan region.
3) Polygalacturonase (EC 3.2.1.15) cuts the linear chain of
galacturonic acid in the homogalacturonan region.
4) Pectin esterase (EC 3.1.1.11) releases the methyl residue
linked to the galacturonic acid.
During fruit ripening, pectin is broken down by pectinesterase, so fruit becomes softer as the middle lamellae break down
and cells become separated from each other

40. Fruit Juice Extraction & Clarification
• It decreases filtration time up to 50%
• increase in fruit juice volume from banana, grapes and apples
• Vacuum infusion of pectinases to soften the peel of citrus fruits for its removal.
• Infusion of free stone peaches with pectin methylesterase and calcium results in four times firmer fruits.
 Acid pectinases (produced by fungi espacially Aspergillus niger)
Degumming Of Plant Bast Fibers
• pectinases in combination with xylanases presents an ecofriendly and economic alternative to chemical
degumming of jute, sunn hemp, flax, ramie and coconut fibers for textile application
Textile Processing And Bioscouring Of Cotton Fibers
• In conjugation with other enzymes used to remove sizing agents from cotton
• removal of noncellulosic impurities from the fibers
 Alkaline pectinases (produced by bacteria particullarly Bacillus sp.)

41. Coffee And Tea Fermentation
• accelerates tea fermentation and also destroys the foam forming property of instant tea powders
by destroying pectins
• Coffee fermentation to remove mucilaginous coat from coffee beans.
Paper And Pulp Industry
• Depolymerise pectins and subsequently lower the cationic demand of pectin solutions and the
filtrate from peroxide bleaching
Animal Feed
• reduces the feed viscosity, which increases absorption of nutrients
Oil Extraction
• degrading cell wall components like pectin enzymes promote the oil liberation

42. Other POLYSACCHARIDES
4.3.1) BETA-GLUCAN
 β-Glucans (beta-glucans) are polysaccharides of D-glucose monomers linked by β-glycosidic bonds.
 B-glucans are chains of D-glucose polysaccharides, linked by b-type glycosidic bonds having branching glucose side chain
 The most active forms of β-glucans are those comprising D-glucose units with (1,3) links and with side-chains of D-glucose
attached at the (1,6) position. These are referred to as β-1,3/1,6 glucan as in seaweed.
 e.g. Laminarin from the brown seaweed Laminaria digitata is a linear β(1-3)-glucan with β(1-6)-linkages.
 β(1,3)(1,4)-glucans are also extracted from the bran of some grains, such as oats and barley, lesser in rye and wheat.
Endohydrolysis of (1->3)- or (1->4)-linkages in beta-D-glucans
Lamarinase (endo-1,3(4)-beta-glucanase) :
Enzymes breaking
down Glucan
4.3) GLUCANS

43. • Dextran is a complex, branched ALPHA glucan composed of chains of varying lengths (from 3 to 2000 kD).
• The straight chain consists of α-1,6 glycosidic linkages between glucose molecules, while branches begin from
α-1,3 linkages. Dextran is synthesized from sucrose by certain lactic acid bacteria, the best-known being
Leuconostoc mesenteroides and Streptococcus mutans. Dental plaque is rich in dextrans
Dextranase (EC 3.2.1.11, dextran hydrolase, endodextranase, dextranase
DL 2, DL 2, endo-dextranase, alpha-D-1,6-glucan-6-glucanohydrolase,
1,6-alpha-D-glucan 6-glucanohydrolase):
It is an enzyme with system name 6-alpha-D-glucan 6-glucanohydrolase.
This enzyme catalyses the following chemical reaction : Endohydrolysis of
(1->6)-alpha-D-glucosidic linkages in dextran
4.3.1) DEXTRAN
4.3 ) GLUCANS
Enzymes breaking
down DEXTRAN

44.  Improve both quality and yields of the beer and wine. Glucanases are added either during mashing or primary fermentation
to hydrolyze glucan, reduce the viscosity of wort, and improve the filterability
 Malting of barley depends on seed germination, which initiates the biosynthesis and activation of α- and β-amylases,and β-
glucanase that hydrolyze the seed reserves
 beta-Glucanases as a tool for the control of wine spoilage yeasts Zygosaccharomyces bailii, and Zygosaccharomyces
bisporus.
BEVERAGE INDUSTRY
 β-Glucanases and xylanases have been used in the feed of monogastric animals to hydrolyze nonstarch polysaccharides
such as β-glucans and arabinoxylans
 Glucanases and xylanases reduce viscosity of high fibre rye- and barley-based feeds in poultry and pig
ANIMAL FEED INDUSTRY
 In sugar production, dextrans are undesirable compounds synthesized by contaminant microorganisms from sucrose,
increasing the viscosity of the flow and reducing industrial recovery, bringing about significant losses.
 The presence of dextrans during evaporation provokes an increase of scale deposits in the heating surface and hence a
greater energy loss.
 The use of the dextranase enzyme is the most efficient method for hydrolyzing the dextrans at sugar mills.
SUGAR INDUSTRY

45. 6.2) CHITOSAN
 Chitin (C8H13O5N)n is a long-chain polymer of a N-acetylglucosamine. These units form covalent β-1,4 linkages
 It is a characteristic component of the cell walls of fungi, the exoskeletons of arthropods such as crustaceans (e.g., crabs,
lobsters and shrimps) and insects, the radulae of molluscs, and the beaks and internal shells of cephalopods, including
squid and octopuses.
 Chitosan /ˈis a linear polysaccharide composed of randomly distributed β-(1-4)-linked D-glucosamine (deacetylated unit)
and N-acetyl-D-glucosamine (acetylated unit). It is made by treating shrimp and other crustacean shells with the alkali
sodium hydroxide.
6.1.) CHITIN

46.  Chitinases have been divided into 2 main groups:
ENDOCHITINASES (E.C 3.2.1.14) AND EXO-CHITINASES
 The endochitinases randomly split chitin at internal sites, thereby forming the dimer di- cetylchitobiose and soluble low
molecular mass multimers of GlcNAc such as chitotriose, and chitotetraose.
 The exo- chitinases have been further divided into 2 subcategories:
o Chitobiosidases (E.C. 3.2.1.29),:
These are involved in catalyzing the progressive release of di-acetylchitobiose starting at the non-reducing end of the
chitin microfibril.
o 1-4-β-glucosaminidases (E.C. 3.2.1.30):
Cleaving the oligomeric products of endochitinases and chitobiosidases, thereby generating monomers of GlcNAc
Chitinases (E.C 3.2.2.14) are glycosyl hydrolases
 The catabolism of chitin takes place in 2 steps, involving the initial cleavage of the chitin polymer by chitinases into chitin
oligosaccharides and further cleavage to N-acetylglucosamine, and monosaccharides by chitobiases.
Enzymes breaking
down CHITIN

47. Enzymes breaking down CHITOSAN
Chitosanase (EC 3.2.1.132) is an enzyme with system name chitosan N-acetylglucosaminohydrolase.
This enzyme catalyses the :
Endohydrolysis of beta-(1->4)-linkages between D-glucosamine residues in a partly acetylated chitosan
Chitin deacetylase (EC 3.5.1.41):
The enzyme that catalyzes the hydrolysis of acetamido groups of N-acetyl-D-glucosamine in chitin,

48. Source of
chitinase
Plant
insect
Mammal
Microbial
Fungal
bacterial

49.  The foremost application of chitinases is protection against fungal pathogens
 Thus, chitinase-producing organisms are used in agriculture as an effective biocontrol agent against a number
of phytopathogenic fungi.
 Bacterial chitinases have also been shown to be potential insecticides when coupled with other suitable
proteins such as Cry.
 Another major application of chitinases based on their property of dissolution of chitin-containing cell wall is
the acceleration of protoplast generation.
 Chitinase from Streptomyces was found to be active in the generation of protoplasts from Aspergillus oryzae
 Chitinase-producing organisms are also effectively used in the bioconversion process to treat shellfish waste
and also to obtain value-added products from such wastes
 suggested chitin bioconversion to single cell protein.
 They are involved in the signaling for root nodule formation, act as elicitors of plant defense and also have
a potential to be used in human medicines (e.g., anti-tumor activity is shown by chitohexaose,
Chitoheptaose).
 Due to their topical applications, they have a prospective use in anti-fungal creams and lotions. A number of
artificial medical articles such as contact lenses, artificial skin, and surgical stitches have been formed from
chitin derivatives.

50.  A fructan is a polymer of fructose molecules.
 Fructans occur in foods such as agave, artichokes, asparagus, leeks, garlic, onions (including spring
onions), yacón, jícama, and wheat.
 The linkage position of the fructose residues determine the type of the fructan.
 Linkage normally occurs at one of the two primary hydroxyls (OH-1 or OH-6), and there are two
basic types of simple fructan:
 1-linked: In Inulin, the fructosyl residues are linked by β-2,1-linkages.
 6-linked: In Levan (or Phlein), the fructosyl residues are linked by β-2,6-linkages.
7) FRUCTAN

51. 7.1.) INULIN
 Inulins are a group of naturally occurring polysaccharides produced by many types of plants, industrially most often
extracted from chicory.
 Inulin is used by some plants as a means of storing energy and is typically found in roots or rhizomes. Most plants that
synthesize and store inulin do not store other forms of carbohydrate such as starch.
 Inulin is a generic term to cover all beta(2-->1) linear fructans.
 Inulinase (EC 3.2.1.7, inulase, endoinulinase, endo-inulinase, exoinulinase, 2,1-beta-D-fructan
fructanohydrolase)
It is an enzyme with system name 1-beta-D-fructan fructanohydrolase. This enzyme catalyses the following chemical
reaction:
Endohydrolysis of (2->1)-beta-D-fructosidic linkages in inulin
Enzymes breaking down INULIN

52. Levans are a group of fructans; polymers of fructose forming a non-structural carbohydrate,
Levanase (EC 3.2.1.65, levan hydrolase, 2,6-beta-D-fructan fructanohydrolase) is an enzyme with system
name (2->6)-beta-D-fructan fructanohydrolase :
This enzyme catalyses the following chemical reaction:
Random hydrolysis of (2->6)-beta-D-fructofuranosidic linkages in (2->6)-beta-D-fructans (levans) containing more
than 3 fructose units
7.2) LEVAN
Enzymes breaking down LEVAN

53.  A simple and high productivity method to obtain high fructose syrup is the enzymatic hydrolysis of inulin, a
single step process that uses inulinases and yields 95% pure fructose
 The endo-inulinases are responsible for inulo- oligosaccharides (IOS) production
 IOS have wide applications in food industry: confectionery, milk desserts, yoghurt and cheese production,
bakery, chocolate, ice-cream and sauces (Chi et al., 2011). It was found that the major IOS obtained after
inulin hydrolysis with endo-inulinases have a
 Inulo- oligosaccharides are prebiotics; their positive effect on human health
 Inulinases have also found their application for inulin substrates hydrolysis for single-cell oil and single-cell
protein production . The marine yeast Cryptococcus aureus can be used for single cell protein production by
cultivation on inulin hydrolysates from Jerusalem artichoke tubers. The same applications are important to
produce citric acid, 2,3 butanediol, lactic acid and sugar alcohols, like mannitol
 Crude enzyme of the strain rich in levanase was established for the hydrolysis of levan in order to produce
fructooligosaccharides with variable degrees of polymerization which could be used in important fields
such medicine, food-processing industry and cosmetic