4. Industrial Media and the Nutrition of Industrial Organisms

THE BASIC NUTRIENT REQUIREMENTS OF INDUSTRIAL MEDIA Carbon or energy requirements Nitrogen is found in proteins including enzymes as well as in nucleic acids Minerals Growth Factors

Average composition of microorganisms (% dry weight)

CRITERIA FOR THE CHOICE OF RAW MATERIALS USED IN INDUSTRIAL MEDIA Cost of the material Ready availability of the raw material Transportation costs Ease of disposal of wastes resulting from the raw materials Uniformity in the quality of the raw material and ease of standardization Adequate chemical composition of medium Presence of relevant precursors Satisfaction of growth and production requirements of the microorganisms

SOME RAW MATERIALS USED IN COMPOUNDING INDUSTRIAL MEDIA Corn steep liquor Pharmamedia Distillers soluble Soya bean meal Molasses Sulfite liquor Other Substrates (alcohol, acetic acid, methanol, methane, and fractions of crude petroleum)

Corn steep liquor This is a by-product of starch manufacture from maize. As a nutrient for most industrial organisms corn steep liquor is considered adequate, rich in carbohydrates, nitrogen, vitamins, and minerals. highly acidic, it must be neutralized (usually with CaCO3) before use.

Approximate composition of corn steep liquor (%)

Pharmamedia yellow fine powder made from cotton-seed embryo. It is used in the manufacture of tetracycline and some semi-synthetic penicillins. rich in protein, (56% w/v) and contains 24% carbohydrate, 5% oil, and 4% ash rich in calcium, iron, chloride, phosphorous, and sulfate.

Distillers soluble by-product of the distillation of alcohol from fermented grain. (maize or barley) It is rich in nitrogen, minerals, and growth factors.

Composition of maize distillers soluble

Soya bean meal The seeds are heated before being extracted for oil that is used for food, as an antifoam in industrial fermentations, or used for the manufacture of margarine. The resulting dried material, soya bean meal, has about 11% nitrogen, and 30% carbohydrate and may be used as animal feed. Its nitrogen is more complex than that found in corn steep liquor not readily available to most microorganisms, except actinomycetes. It is used particularly in tetracycline and streptomycin fermentations.

Molasses

Sulfite Liquor Sulfite liquor (also called waste sulfite liquor, sulfite waste liquor or spent sulfite liquor) is the aqueous effluent resulting from the sulfite process for manufacturing cellulose or pulp from wood. During the sulfite process, hemicelluloses hydrolyze and dissolve to yield the hexose sugars, glucose, mannose, galactose, fructose and the pentose sugars, xylose, and arabinose. Used as a medium for the growth of microorganisms after being suitably neutralized with CaCO3 and enriched with ammonium salts or urea, and other nutrients.

It has been used for the manufacture of yeasts and alcohol. Some samples do not contain enough assaimilable carbonaceous materials for some modern fermentations. They are therefore often enriched with malt extract, yeast autolysate, etc.

GROWTH FACTORS Not synthesized by the organism Must be added to the medium. Function as cofactors of enzymes and may be vitamins, nucleotides etc. The pure forms are usually too expensive for use in industrial media Growth factors are required only in small amounts.

Some sources of growth factors

Some Potential Sources of Components of Industrial Media Carbohydrate Sources Cassava Sweet potato Yams Cocoyam Millets Rice Sorghum Jerusalem artichoke

Protein Sources (a) Peanut (groundnut) meal (b) Blood meal (c) Fish Meal

THE USE OF PLANT WASTE MATERIALS IN INDUSTRIAL MICROBIOLOGY MEDIA: SACCHARIFICATION OF POLYSACCHARIDES

Not only plentiful but that in contrast with petroleum, a major source of chemicals, they are also renewable. Contain large amounts of polysaccharides which are not immediately utilizable by industrial microorganisms Need to be hydrolyzed or saccharified to provide the more available sugars. Thereafter the sugars may be fermented to ethyl alcohol for use as a chemical feed stock. The plant polysaccharides starch, cellulose and hemicelluloses.