The document discusses microbial polysaccharides, focusing on production methods, particularly of xanthan gum, and their various applications in food and pharmaceuticals. It outlines the fermentation processes, recovery techniques, and the commercial significance of different polysaccharides including xanthan, gellan, pullulan, and dextran. These polysaccharides are noted for their properties as thickening, gelling, and stabilizing agents in various food products.

1. PRODUCTION AND PURIFICATION OF MICROBIAL
POLYSACCHARIDES
Prepared by –
Mr Pathan Arshad Khan I.A.
Assistant Professor
Gramin Science College, Vishnupuri ,
Nanded

2. CONTENTS
 Introduction of microbial polysaccharides
 Types
 Production of Xanthan gum
 Introduction
 Process
 Fermentation
 Recovery
 Application of some microbial polysaccharides-
 Xanthan gum
 Gellan
 Pullulan
 Dextran
 Xylinan / Acetobacter xylinum cellulose
 Alginate
 Curdlan

3.  Polysaccharides are the carbon sources which are found in huge
amount in the biosphere.
 Used for food, pharmaceutical, and medical applications.
 Derives from the great diversity in structural and functional
properties.
 Xanthan, Xylinan, Gellan, Curdlan, Pullulan, Dextran,
Scleroglucan, Schizophyllan, and Cyanobacterial polysaccharides.
 The commercial value of polysaccharides is based on its ability to
modify the flow characteristics of solutions (Rheology).
 They can increase viscosity and hence used as thickening and
gelling agents.
 Polysaccharides made by microorganisms are secreted from the
cell to form a layer over the surface of the organism.
 Certain microbes are known to produce nearly all the major plant
polysaccharides such as glucans, alginate-like materials
Introduction

4. Types
Capsular
polysaccharides
Exo-
polysaccharides
Secreted out by the micro-
organisms
However evolved to avoid
any antibody responses.
Protective capsule and thus prevent
the pathogenic micro- organism
from immune system defenses.
Act as barrier in preventing the
harmful intruders
As extracting these polysaccharides at low cost in larger quantities makes
it more useful in any research industries.
Bulk amount of these microbial polysaccharides are used in food industry
such as xanthan to dextran.
Due to their unique structure and physical properties they are widely used
as emulsifiers, stabilizers, thickeners, viscosifiers, film-formers and gelling
agents.

6. Production
of
Xanthan gum
https://youtu.be/D4taxsButo8

7.  Natural polysaccharide and an important industrial biopolymer.
 It was discovered in the 1950s at the Northern Regional Research
Laboratories (NRRL).
 Produced by the bacterium Xanthomonas campestris.
 Heteropolysaccharide with a primary structure consisting of
repeated pentasaccharide units formed by two glucose units, two
mannose units, and one glucuronic acid units.
 Polysaccharides such as glucans, alginate-like materials
Introduction

8.  First, the selected microbial strain is preserved for possible long-
term storage by proven methods to maintain the desired properties.
 A small amount of the preserved culture is expanded by growth on
solid surfaces or in liquid media to obtain the inoculum for large
bioreactors.
 Aerobic fermentation process such as the type of bioreactor used,
the mode of operation (batch or continuous), the medium
composition, and the culture conditions (temperature, pH,
dissolved oxygen concentration).
Process

9. Fig- Production of Xanthan gum

10.  X. campestris needs several nutrients, including micronutrients
(e.g. potassium, iron, and calcium salts) and macronutrients such
as carbon and nitrogen.
 Glucose and sucrose are the most frequently used carbon source
concentration of 2-4% is preferred.
 Growth temperature X. campestris has been cultured at different
temperatures ranging from 25 to 30°C.
 pH decreases from neutral pH to values close to 5 because of acid
groups present in xanthan.
 Sparged stirred tank is employed most frequently when the stirrer
speed was constant at < 500 rpm,
Fermentation Process

11.  At the end of the fermentation, the broth contains xanthan,
bacterial cells, and many other chemicals.
 For recovering the xanthan, the cells are usually removed first,
either by filtration or centrifugation (Flores Candia and Deckwer,
1999).
 Further purification may include precipitation using water-miscible
non-solvents (isopropanol, ethanol, acetone), addition of certain
salts, and pH adjustments (Flores Candia and Deckwer, 1999).
 The FDA regulations for food grade xanthan gum prescribe the use
of isopropanol for precipitation.
 After precipitation, the product is mechanically dewatered and
dried.
Recovery

12.  The high viscosity at very low concentrations makes it an excellent
agent as food additive for syruping, stabilizer and as a thickening
agent.
 Low calorie drinks which increase the thinning consistency where the
total or partial sugars are replaced by artificial sweeteners.
 Stabilizer in most liquid and semi-liquid foods and gives a body form
to most dairy products.
 Freeze thaw stability its major food additive in frozen food industries.
 Extensively used in bakery products to help retention of water in
baking food and therefore increases the shelf life of the food.
 It’s used in low fat food to increase the viscosity of the aqueous phase
and stabilize the food system mayonnaise, cheese, ready-to-eat meals
etc.
 Xanthan was approved by FDA as food additive.
 it’s widely used in commercial food industry.
Applications of Xanthan gum

13.  Gellan is synthesized by bacterium Sphingomonas paucimobilis.
 It was approved by FDA as a food additive in the year 1992.
 It is used as stabilizer, gelling agent and as thickening agent in many
food sources.
 It provides structure, texture and mouth feel in many food substances
rather than gelatin.
 It’s mostly used in confectionary units to reduce the set time of gelling
such as starch jellies, prevents the moisture loss in these sugary foods.
 Gellan can replace pectin in jams with low concentrations use when
compared to pectin.
 Modified starch food to increase the stability as stabilizer and water
binding agent preventing the “blunting effect”.
 Fabricated food like meat, fruits, confectioneries fall into this
category.
Applications of Gellan

14.  Pullulan is a type of exo-polysaccharide which is derived from a
fungus Aureobasidium pullulans.
 A white to off-white tasteless, odorless powder that forms a viscous
non-hygroscopic solution when dissolved in water at 5-10%. used in
the production of capsule shells as well as coated tablets for the
preparation of dietary supplements.
 It has particularly used to make snack foods in Japan which are based
on cod roe and powdered cheese.
 It uses at low doses as it is slowly digested in humans.
 It is used to make packaging film for ham.
Applications of Pullulan

15.  Dextran is a linear polysaccharide which is obtained from the
Leuconostoc mesenteroides.
 It is the first microbial polysaccharide that has got commercialized
and approved for used in food.
 It is used in pudding mixes to provide them with texture and mouth
feel.
Applications of Dextran

16.  Xylinan is the microbial exo-polysaccharide i.e. obtained from the
Acetobacter xylinum gram-negative bacteria.
 This component has made its place in the food industry as
viscosifying and gelling agent having high gel strength, water-holding
capacity and is easy to mold.
 Actually, it is the major component in nata de coco, a confectionery
which is widespread in Japan and Philippines.
Applications of Xylinan / Acetobacter xylinum
cellulose

17.  Alginates mainly from the liquid bacterial cultures such as
Pseudomonas aeruginosa, Azotobacter chrocococcum and
Azotobacter vinelandii .
 one as they can be used for large-scale industrial production of
alginates
 P. aeruginosa which is an infective agent which is found to be
associated with respiratory disease and cystic fibrosis.
 Due to their thickening, stabilizing and gelling properties which can
be applied to wide range of foods such as jams, soups, sauces, meat,
fish, beverages, dairy products and confectionery.
 They possess anti-inflammatory and detoxifying properties
Applications of Alginates

18.  Curdlan is a high molecular weight polysaccharide obtained from
Alcaligenes faecalis.
 It is the improved version of the gums providing viscosity,
rehydration, gelling and texture-modification properties
Applications of Curdlan

19. Thank You