In biotechnological applications, bacteria are cultured usually by batch-fermentation on a large scale to produce chemical products such as vitamins and enzymes in industrial quantities. (The Oxford Interactive Encyclopedia)
Bacteria can be genetically modified and bacteria may banish tooth decay. According to dental researcher Jeffrey Hillman at the University of Florida in Gainesville
a mouthful of genetically modified bacteria could keep tooth decay away for life. The scheme involves replacing your mouth's natural cavity-causing bacteria with GM bacteria designed to prevent tooth decay. By inhibiting Streptococcus mutans that convertsugar to lactic acid and slowly etch away the enamel on teeth.
(http://www.newscientist.com/news/news.jsp?id=ns99991941)
The technicalogical applications of bacteria are advantageous. The enzymes contained in different bacteria can be used in the dairy industry- extracellular lipase is used to ripen blue chesses from mould e.g Penicillum roguefortii. The production of cheese by separating milk into curd and whey may be achieved by the addition to the milk of the enzyme rennet or by the addition of a bacterial culture. Also In the ripening process, micro-organisms, most commonly lactic-acid-producing bacteria, act on the cheese to produce the desired body and flavour. (The Oxford Interactive Encyclopedia)
Bacteria have a high growth rate and so bacteria can be used to help farmers save crops as they are used for genetic engineering; for example, bacteria can be used to insert genes for disease or herbicide resistance into plants. These are also used in biological pest control and are also necessary for the breakdown of sewage.
The disadvantages of bacteria are that bacteriophages are a serious problem if they infect the contents of an industrial fermentor. Bacteria are expensive to purify and often unstable in the purified state. Ethically the use of bacteria in the cloning of animals is controversial. At the Roslin Institute in Scotland, scientists successfully cloned an exact copy of a sheep, named 'Dolly'. This was the first successful cloning of an animal and most likely the first occurrence of two organisms being genetically identical.Recently the sheep's health however has deteriorated detrimentally. Many people especially on the grounds of religion think it is immoral to "play God" by the use of modified bacteria.
(http://www.biology-online.org/2/13_genetic_engineering.htm).
The enzymes in the bacteria are highly sensitive to changes in the physical and chemical environment surrounding them- environmental disadvantage. They may be denatured by even a small temperature rise and change in pH. This means that the conditions in which they work must be stringently controlled. In particular the enzyme-substrate mixture must not be contaminated with other substances that might affect the reaction so the equipment used must be scrupulously clean- this is time consuming, so an economic disadvantage.
In conclusion it seems that bacteria have more advantages than disadvantages and they may well lead to positive developments in the future.
Bibliography
Newscientist.com
biologyonline.com
AS Biology "A New Introduction to Biology"
Bill Indge
Martin Rowland
Margaret Baker
Published-2000.
The Oxford Interactive Encyclopedia Version 1.0.1
