biotechnology

The genetic modification of a bacterium to produce insulin. The human gene for the production of insulin is collected from a donor chromosome and spliced into a vector plasmid (DNA found in bacteria but separate from the bacterial chromosomes). The plasmids and recipient bacteria are mixed together, during which process the bacteria absorb the plasmids. The plasmids replicate as the bacteria divide asexually (producing clones) and begin to produce insulin.

Industrial use of living organisms. Examples of its uses include fermentation, genetic engineering (gene technology), and the manipulation of reproduction. The brewing and baking industries have long relied on the yeast micro-organism for fermentation purposes, while the dairy industry employs a range of bacteria and fungi to convert milk into cheeses and yoghurts. Enzymes, whether extracted from cells or produced artificially, are central to most biotechnological applications. Recent advances include genetic engineering, in which single-celled organisms with modified DNA are used to produce insulin and other drugs.

There are many medical and industrial applications of the use of micro-organisms, such as drug production. One important area is the production of antibiotics such as penicillin.

It is thought that biotechnology may be helpful in reducing world food shortages. Micro-organisms grow very quickly in suitable conditions and they often take substances that humans cannot eat and use them to produce foods that we can eat.

Fermentation Many food, drink, and industrial processes use micro-organisms. Micro-organisms can be introduced into a substance on which they are able to feed. The micro-organisms use the food source to obtain energy and in this process change some substances into others. These new substances may be useful to us. This process, fermentation, is often carried out in a vessel called a fermenter.

Fermenters require specific conditions, which include excluding other micro-organisms (aseptic precautions), monitoring nutrient supply, providing the optimum temperature and acidity (pH), oxygenation, and agitation (mechanical mixing).

Micro-organisms and food production The main advantages of using micro-organisms in food production are rapid population growth, ease of manipulation, production not being affected by climate, and use of waste products from other industrial processes.

Micro-organisms are applied in a variety of ways to produce food. Bacteria are used in the production of yoghurt from milk by the conversion of lactose (milk sugar) to lactic acid. Mycoprotein, a protein food, is produced from a fungus (Fusarium). It results in a food that has the texture of a white meat, but as it is not produced from any animal product it is suitable for vegetarians. This and similar examples may be referred to as ‘single-cell protein’.

Soy sauce is made from a mixture of cooked soya beans and roasted wheat using the fungus Aspergillus to ferment it. It is then further fermented using other fungi (yeasts) and then the bacterium Lactobacillus. Finally it is filtered, pasteurized, and then bottled in sterile (aseptic) conditions.

Other uses Enzymes extracted from micro-organisms grown in fermenters give us proteases and lipases that are used in biological washing powders.

Legislation European legislation on the production, health, and environmental implications of biotechnology applications is being continually amended to keep pace with the speed of development in this field.