ABBOTTS

BIOTECHNOLOGY

BIOTECHNOLOGY

• • the use of micro-organisms by humans to make substances, humans want E.g. In the manufacture of food, antibiotics, biogas These substances include: Medicines antibiotics and insulin Food Maas, bread, wine and cheese

Antibiotics

• Antibiotics can be made naturally by a process called biosynthesis • It involves the formation of a chemical compound by a living organism • Natural antibiotics are made by fungi ▫ ▫ E.g. Penicillium which grows on fruit Streptomyces which grows in soil

INSULIN PRODUCTION

• • • • • • • Insulin is a hormone which regulates the concentration of blood sugar People suffering from diabetes mellitus cannot make insulin Have to have daily injections of insulin Used to get insulin from pigs Today genetic engineering has produced bacteria which can make human insulin Bacteria are grown in large vats Insulin is extracted and purified

TRADITIONAL TECHNOLOGY

ANAEROBIC RESPIRATION • • • Many of these processes involve anaerobic respiration – respiration without oxygen Sugars are changed into alcohol and carbon dioxide – alcoholic fermentation During this process, in the presence of sugar, some bacteria and fungi produce: ▫ fermented foods Sugars are changed into alcohol ▫ ▫ alcoholic drinks breads And large quantities of carbon dioxide

TRADITIONAL TECHNOLOGY IN FOOD PRODUCTION

▫ ▫ ▫ SORGHUM BEER MAAS MAHEWU

ALCOHOLIC DRINKS BEER

• • • • Beer is made by a process known as brewing Dried, crushed germinating barley seeds (contain the sugar maltose), water, hops (for flavour) and yeast are mixed Yeast respires anaerobically producing alcohol and carbon dioxide (gives beer the bubbles) When fermentation is complete the excess yeast is skimmed off and is used to produce yeast extracts such as Marmite 8

MAHEWU

TRADITIONAL SOUTH AFRICAN BEER • • • • • Traditional South African non alcoholic energy providing drink Made from fermented maize meal or sorghum, malt, yeast and water Commercially available at supermarkets Similar to mealie meal but with sugar changed to lactic acid during fermentation Commercial preparations are often enriched with vitamins and minerals

ALCOHOLIC DRINKS - WINE

• • • • • Wine is produced from grapes Can be made from many other types of fruit Yeast cells found on the grape skins ferment grape sugar turning it into alcohol and carbon dioxide Grape juice is allowed to ferment and bottled

BACTERIA IN THE FOOD INDUSTRY

• • • • • • Fermented dairy products The bacterium

Lactobacillus acidophilus

causes pasteurised milk to ferment Lactose is converted into lactic acid Lowers the pH of the milk Causes the protein caseinogen to coagulate starting process for making yoghurt and some cheeses The increased acidity prevents the proliferation of pathogenic bacteria

BACTERIA IN THE FOOD INDUSTRY

• • • • • • • • Cheese making An enzyme rennin is added to curdled (acidified) milk Causes further coagulation forming curds and whey Curds and whey are separated Curds are drained and pressed into cheese To produce a variety of cheeses, different incubation periods, milks and bacteria are used Process is complicated Can take from months to a year to complete

EXTRA

NON-DAIRY FERMENTED FOOD PRODUCTS

• • • • Acetic and lactic acid are produced by fermentation bacteria The acids protect the food against decay Fermented foods meats and fish acid bacteria – pickles, olives, sauerkraut, cured – are usually produced by lactic Vinegar is produced by acetic acid bacteria acting on wine, cider or other alcoholic beverages to produce acetic acid

FUNGI IN THE FOOD INDUSTRY

• Yeast and certain moulds are used in biotechnology • • Yeast is a unicellular fungus It is the smallest fungus but it is economically extremely important in the production of bread and alcoholic drinks

EXTRA

BREAD MAKING

• • • Bread is made from a mixture of flour, a little sugar and yeast During the process yeast ferments sugar and gives off carbon dioxide and alcohol Carbon dioxide makes the dough rise while alcohol evaporates

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