The History of Biotechnology

Dairy Cow - Zoe Bianchi

The origins of biotechnology can be traced to the beginning of the Agricultural Revolution around 10000 years ago. In its earliest forms it included the collection and sowing of selected seeds, trapping eels, domesticating animals and making wine, beer and yoghurt.

During this period humans began selecting and herding animals with high meat or milk producing qualities. Modern dairy and beef cattle have in fact originated from the primitive Auroch, a long haired animal with large horns. Dairy cattle such as the Guernsey (see figure 1) are the result of years of selecting for high milk production and milk fat content, while meat producing breeds such as the Aberdeen Angus have been selected for high body mass, reduced hair, short horns and red coat colour.

Artificial Selection of Animals 

Other early instances of the domestication of animals include the taming of donkeys in Egypt and camels in South America around 3000 years ago and the cultivation of silkworm moths in China during the same period. Modern day poultry have arisen from the red jungle fowl, which was domesticated around 2000 BC in Asia, while Australian Aboriginals dug channels to connect ponds and trap eels as long ago as 18000 BC. Early farmers often found that hybrid strains of animals and plants often possessed more favourable characteristics.

Artificial Selection of Plants

Wheat has also been artificially selected over thousands of years to produce Triticum aestivum, the bread wheat we are familiar with today. This modern species of wheat arose from a hybrid strain, Triticum turgidum (also known as Emmer wheat), which was itself the result of the hybridisation of Triticum monococcum and wild Triticum. Hybrid plants are usually sterile but Emmer wheat arose from a meiotic error in one of the initial hybrid plants.

This resulted in a plant with duplicate sets of chromosomes from each species which could now undergo meiosis to produce gametes. Further breeding experiments such as those carried out by Australian William Farrer have produced wheat with favourable characteristics such as rust and drought resistance, short stalks and high yielding ears.

Corn, first cultivated in South America, has also been selected over the years for favourable traits such as colour, size, flavour and cobs with large numbers of seeds that mature on the stem. Traders introduced corn into Europe in the 15th and 16th centuries.

The Use of Fermentation in Early Biotechnology

Early biotechnology also took advantage of the natural metabolic processes of various microorganisms to produce wine, beer, bread, yoghurts and cheeses. When yeasts break down sugars in respiration, carbon dioxide and ethanol are produced. Wild yeasts naturally present in fruit were therefore used in the production of wine from around 2000 years ago in Egypt and Assyria, while yeasts present in germinated barley were used to produce beer as early as 6000 years ago in Egypt, Mesopotamia and Greece.

Lactic acid bacteria, naturally present in milk, also break down sugars in respiration, but the product of this reaction is lactic acid. This process was first used to produce yoghurts and cheeses in the Middle East several thousand years ago. Australian Aboriginals also fermented the nectar of native flowers to produce a sweet beverage and used fermentation to remove the natural toxins in cycad seeds.

Another type of microbe, Acetobacter, converts ethanol to acetic acid (vinegar) in the presence of oxygen. This natural souring of wine was observed thousands of years ago, with the first recorded use of vinegar as a preservative and condiment occurring in Babylon in 5000 BC.

Fermentation and Modern Technology

With the development of the steam engine in 1775, fermentation equipment could be sterilised and more elaborate machines could be made to produce wine, beer and other products on a large scale. The invention of refrigeration also allowed large quantities of alcoholic beverages and other fermentation products to be stored for longer periods of time.

The development of the microscope allowed scientists such as Louis Pasteur to make a definite connection between microbes and their respiration products: yeast, for instance, was found to be necessary for the production of ethanol and lactic acid bacteria were found to be necessary for the production of yoghurt.

Moreover, research into the growth and nutrition requirements of different types of microbes enabled optimum cultivation conditions for these organisms to be established in specialised ‘bioreactors’. Bioreactors are large steel vats which are supplied with the specific nutrient, aeration and temperature needs of particular microorganisms.

In the production of citric acid, for instance, the fungus Aspergillus niger is grown in a bioreactor on a molasses substrate that is low in iron. In vinegar production the bacterium Acetobacter is cultivated in a bioreactor that is continuously aerated, while the yeast biomass required to produce baker’s yeast is also grown in aerated conditions under strictly controlled temperatures.

Biotechnology Today

In addition to fermentation and the artificial selection of plants and animals, biotechnology today also includes genetic engineering, gene therapy, DNA fingerprinting, the production of monoclonal antibodies and antibiotics such as penicillin, tissue engineering and the production of recombinant vaccines. Although these are more sophisticated than early examples of biotechnology, they are nonetheless instances of humans gaining benefit from the use of living organisms or their processes.

References

History World, ‘History of Domestication of Animals’, historyworld.net, accessed 24/6/2010

Kennedy, Hickman, 2004, ‘Biology in Context, the Spectrum of Life: Biotechnology Option’, Oxford Press

Ptolemy, Alexander, 2009, ‘A Brief History of Vinegar- The Remarkable Liquid’, associatedcontent.com, accessed 25/6/2010