Biopolymers 1 Dextran 2 Alginate 3 Xanthan 4

Biopolymers 1. Dextran 2. Alginate 3. Xanthan 4. Pullulan Dr. Kunal Kishor Assistant Professor, Department of Life Sciences, SGRRITS Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

CONTENT – Microbial strains – Substrates – Flow Diagram of Production – Applications Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

INTRODUCTION – Biopolymers are polymeric biomolecules produced by living organisms. – They contain monomeric units that are covalently bonded to form larger structures. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Production of biopolymers by microbial strains – Different microbial strains are used to produce biopolymers with the help of naturally occurring substrates which may be of no use to many industries. – It is an eco – friendly method of utilizing the waste products and exploiting the microbes in balanced manner. – The modern method of production have changed the view of utility and uses of biopolymers in safe and economic way. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

DEXTRAN – Dextran is the generic name of a large family of microbial polysaccharides that are assembled or polymerized outside the cell. – This class of polysaccharides is composed of building blocks (monomers) of the simple sugar glucose and is stored as fuel in yeasts and bacteria. – Dextran is produced by fermentation or enzymatic conversion of the feedstock sucrose, a product of the sugar beet and sugarcane industries. – DEXTRAN, (C 6 H 10 O 5)n is a polysaccharide consisting of glucose monomers linked mainly (95%) by α(1– 6) bonds. – The bacterium (Leuconostoc mesenteroides) is grown in a sucrose-rich media releasing an enzyme, dextransucrase, which converts excess sucrose to dextran and fructose. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Microbial Strain used- Leuconostoc mesenteroides Substrate. Feedstock sucrose (sugar beet) Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

– Dextran was first discovered by Louis Pasteur as a microbial product in wine. – Apart from L. mesenteroides, Saccharomyces cerevisiae and Lactobacillus spp. are also used in bakery industries. – Dental plaque is rich in dextrans. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Production of Dextran – Composition of the basic medium: 5% sucrose 1 % peptone 0. 1% KCI 0. 55% Na 2 HPO 4 0. 075% Na 3 P 04 0. 33% yeast extract – The basic media is inoculated with 10% inoculums after sterilization. – Fermentation is effected in an air thermostat at 28° C. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Flow Diagram of Production of Dextran at Industrial level Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Applications of Dextran – The industrial production of dextran, considered before as a harmful by-product of beet sugar production, has gained importance since it has been used in big quantities, as e. g. a substitute for blood plasma, as flocculation agent, medicine with iron content or a flotation agent. – Chemically modified dextran such as dextran sulfate have both antiulcer and anticoagulant properties. – In the industrial area, dextrans are being incorporated into x-ray and other photographic emulsions. – Dextrans are used extensively in oil drilling muds to improve the ease and efficiency of oil recovery. – They also have potential use in agriculture as seed dressings and soil conditioners. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

ALGINATE – Alginate, also called algin or alginic acid, is an anionic polysaccharide distributed widely in the cell walls of brown algae. – Its colour ranges from white to yellowish-brown. It is sold in filamentous, granular or powdered forms. – They are chain-forming heteropolysaccharides made up of blocks of mannuronic acid and guluronic acid. – E. C. C. Stanford, a Scottish chemist, discovered alginates from British kelp in the 1880 s. – Commercial varieties of alginate are extracted from seaweed, including the giant kelp Macrocystis pyrifera, Ascophyllum nodosum, and various types of Laminaria. It is also produced by two bacterial genera Pseudomonas and Azotobacter. Bacterial alginates are useful for the production of micro or nanostructures suitable for medical applications. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Microbial Strain used- Pseudomonas and Azotobacter Substrate- Seaweed Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

MANUFACTERING PROCESS 1. Collection of seaweed 2. Crushing 3. Washing and Swelling 4. Extraction 7. Precipitation 5. Clarification 8. Alginic Acid 6. Filtration 9. Drying and Milling Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Flow chart for the production of sodium alginate (after Mc. Hugh, 1987) Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Applications of Alginate – Alginate absorbs water quickly, which makes it useful as an additive in dehydrated products. – It is also used for waterproofing and fireproofing fabrics. – In the food industry as a thickening agent for drinks, ice cream and cosmetics, and as a gelling agent. – Alginate is used as an ingredient in various pharmaceutical preparations, such as Gaviscon, in which it combines with bicarbonate to inhibit reflux. – Sodium alginate is used as an impression-making material in dentistry, prosthetics etc. – Sodium alginate is used in reactive dye printing and as a thickener for reactive dyes in textile screenprinting. Alginates do not react with these dyes and wash out easily, unlike starch-based thickeners. – As a material for micro-encapsulation. – Calcium alginate is used in different types of medical products including skin wound dressings. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

XANTHAN – Xanthan gum, a complex copolymer produced by a bacterium, was one of the first commercially successful bacterial polysaccharides to be produced by fermentation. – It is composed of pentasaccharide repeat units, comprising glucose, mannose, and glucuronic acid in the molar ratio 2: 2: 1. – Xanthan gum was discovered by Allene Rosalind Jeanes and her research team at the United States Department of Agriculture. – It is a high molecular weight natural polysaccharide. (M. w. is 2 -20× 106 Daltons). – The name Xanthan is kept over the name of the microbe from which it is produced. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Microbial Strain used- Xanthomonas campestris Substrate Molasses and Corn syrup Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Flow chart of manufacturing process Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Applications of Xanthan – One of the most remarkable properties of xanthan gum is its ability to produce a large increase in the viscosity of a liquid by adding a very small quantity of gum. – In foods, xanthan gum is most often found in salad dressings and sauces. – Used in frozen foods and beverages, xanthan gum helps create the pleasant texture in many ice creams, along with guar gum and locust bean gum. – Toothpaste often contains xanthan gum, wherein it serves as a binder to keep the product uniform. – Xanthan gum is also used in gluten-free baking. – In the oil industry, xanthan gum is used in large quantities, usually to thicken drilling mud. – Packet soups and many of the fat-free foods available in the market have presence of Xanthan. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

PULLULAN – Pullulan is a linear glucosic polysaccharide produced by the polymorphic fungus. – It is a water-soluble polysaccharide produced outside the cell by several species of yeast. – Pullulan can be chemically modified to produce a polymer that is either less soluble or completely insoluble in water. – Pullulan is a linear a-D-glucan built of maltotriose subunits, connected by (1 -6)-a-Dglucosidic linkages. – Pullulan is being used extensively in the food industry as a food ingredient for over 20 years in Japan, and has Generally Regarded As Safe (GRAS) status in the USA. – It is tasteless, odorless, and nontoxic. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Microbial Strain used. Aureobasidium pullulans Substrate Waste streams containing simple sugars Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

The Structure of Pullulan Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Flow chart of manufacturing process Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS

Applications of Pullulan – Pullulan compounds are biodegradable in biologically active environments, have high heat resistance, and display a wide range of elasticities and solubilities. – Pullulan has many uses as an industrial plastic. It can be formed into compression moldings that resemble polystyrene or polyvinyl chloride. – A completely different application of pullulan can be found in the food industry. It can be used as a food additive, providing bulk and texture. – It does not break down in the presence of naturally occurring digestive enzymes and therefore has no caloric content. – In addition, pullulan inhibits fungal growth and has good moisture retention, and thus can be used as a preservative. Dr. Kunal Kishor, Assistant Professor, Department of Life Sciences, SGRRITS