1. Biotechnology

2. Introduction Biotechnology can be defined as any process that “makes use of living organisms (or parts of them) to produce useful products or services” Biotechnology has a very long history: – Use of microbes in the food industry, for example: Beer and bread making Cheese and yoghurt production Mycoprotein production

3. Microbes were used extensively in the First World War. British used the bacterium Clostridium acetobutylicum to make acetone and butanol. – Acetone was needed for the explosives industry – Butanol was needed for making artificial rubber The Germans used yeast to make glycerol needed for the manufacture of explosives like nitroglycerine. The normal fermentation process is blocked by hydrogen sulphite and causes production of glycerol instead of ethanol.

4. Today, people tend to think that biotechnology is concerned with: – Production of pharmaceuticals and drugs, e.g. antibiotics – Micropropagation and tissue culture – Production of enzymes used in food production and the detergents industry – Genetic engineering and the production of genetically modified organisms (GMOs), for example: Herbicide/pesticide resistant crops Crops with better nutrient levels like Golden Rice™ with high levels of β-carotene (the precursor of vitamin A) Pharming, i.e. modifying farm animals so they produce pharmaceuticals, which can then be obtained from milk

5. Use of Microbes in Biotechnology The following slides provide a few examples of the use of microbes in: – Food industry – Pharmaceutical industry – Enzyme production – Bioremediation and metal extraction TASK: Complete a mind map to summarise these details

6. Cheese and Yoghurt Cheese and yoghurt are fermented milk products. Lactic acid bacteria ferment lactose which changes the consistency of the milk protein casein. – With cheese, the protein coagulates and separates into curds, which are then turned into cheese – With yoghurt, the milk thickens and sets Q. What are the basic differences in cheese and yoghurt production? – Lactic acid bacteria used – Temperature – Use of rennet Brie and Shropshire Blue cheese. The cheese is ripened by fungi on the surface (brie) or within it (Shropshire Blue).

7. Mycoprotein (Quorn™) The filamentous fungus, Fusarium is grown in continuous culture on corn steep liquor. The fungus is: – Extracted and – The mycelium (fungal threads) is textured and flavoured The mycoprotein produced is a low-cholesterol, low-fat meat substitute. Q. Suggest why mycoprotein might be preferred by some people to meats like chicken, lamb, pork and beef. – Ethics (it is not animal) – Health (it is low cholesterol, low fat and high fibre)

8. Soy Sauce and Tofu Soya bean can be fermented to produce soy sauce. The fungi Aspergillus oryzae and A. soyae are used in the fermentation. Although bean curd (tofu) is usually made by precipitating soya protein from soya milk, it can be made using the enzyme papain. Q. What are the health benefits of soya? – High protein, low fat and cholesterol – Meat substitute with full complement of essential amino acids – Source of phyto-oestrogen

9. Yeast Extract The brewing industry makes large amounts of waste yeast (Saccharomyces cerevisiae) It is hydrolysed: – Used to make yeast extracts such as Marmite™ It is rich in a range of B vitamins. Q. Assess the health benefits of yeast extracts like Marmite™. – Good: Rich in B vitamins – niacin, thiamin, riboflavin, folic acid and vitamin. May be an important source for some people. – Bad: Salt content. Individuals with high blood pressure need to control salt intake.

10. Beer and Wine Sugar is fermented to ethanol by the yeast Saccharomyces cerevisiae. – Beers Sugar is from malted barley (or other cereal) – Ciders Sugar is from apple – Wine Sugar is from grapes (or other fruits in country wines) Q. Briefly describe what happens during the malting process. – Cereal grain is wetted and germination starts. Enzymes are produced which convert stored starch into maltose. – Boiled to stop enzyme action and extract the maltose for fermentation.

11. Antibiotics, e.g. penicillin Antibiotics are chemicals made by living organisms that either kill or inhibit the growth of microbes. The first antibiotic to be extracted and produced commercially was penicillin. – Discovered by Alexander Fleming, but production and extraction was developed by Howard Florey and Ernst Chain. Q. Penicillin was initially thought of as a ‘magic bullet’ that could treat most infections. Suggest why it has not lived up to this image. – Only effective against certain (Gram-positive) bacteria with a thick murein/ peptidoglycan cell wall. – Resistance now widespread due to its overuse. Penicillin sensitivity of Bacillus subtilis

12. Human Insulin Type I diabetics do not produce insulin and blood sugar increases. Insulin can be extracted from the pancreas of dead animals – Cattle – bovine insulin – Pigs – porcine insulin The bacterium Escherichia coli has been genetically modified so that it expresses the human insulin gene. Q. Suggest reasons why human insulin has become widely accepted in preference to porcine and bovine insulin. – It is human insulin and so fewer problems experienced. – Ethical and religious reasons. Glucose can be detected in the urine using reagent strips like these. Better control is achieved using electronic blood monitors.

13. Pectinase Pectinase is widely used in fruit juice extraction. – It softens the cell walls – Makes it easier for juice to be extracted – Significantly more juice is extracted if the pulp is treated with pectinase The fungus Aspergillus niger produces pectinase. Q. Suggest an economic reason for the use of pectinase in juice extraction. – More juice from the same amount of fruit More profit Less waste (cheaper disposal)

14. Proteases and Lipases Enzymes are used in biological detergents. – Proteases digest protein based stains (e.g. blood) – Lipases digest fats and oils Cellulases may also be present to remove the outer layers from cellulose fibres and help restore saleroom colours to older, faded garments. Q. Suggest why biological detergents are considered by some to be environmentally friendly. – Effective stain removal at lower temperatures Less energy used to heat water Reduced carbon footprint One brand of biological detergent

15. Meat Tenderisers Meat tenderisers do what they say: – They digest tough protein fibres in meat. Traditionally, tenderisers include: – Papain From papaya – Bromelain From pineapple Fruit pulp can be used Q. Pineapple is sometimes used as a marinade to soften meat before cooking. Why should fresh, rather than tinned pineapple be used? – During the tinning process, the pineapple is heated and so enzymes, including the bromelain, are denatured. Papaya and pineapple.

16. Oil Spill Clean-Up Torrey Canyon (1967); Exxon Valdez in Prince William Sound, Alaska (1989); Sea Empress in Milford Haven, Pembrokeshire (1996); Deepwater Horizon drilling platform, Gulf of Mexico (2010). Strains of Pseudomonas can digest individual hydrocarbon components of oil. GM has produced strains that can digest a range of hydrocarbons, rather than just single ones. Q. What is the benefit of using bacteria to digest the oil from a spill rather than using detergents and labour intensive manual cleaning? – Detergents do not remove oil, simply emulsify it; can be toxic to marine life; labour is expensive. Exxon Valdez after it ran aground on Bligh Reef. Public Domain image: US National Oceanic and Atmospheric Administration.

17. Sewage Treatment Waste water contains organic waste which, if it was released untreated into rivers could cause oxygen depletion. It is treated before release: – Percolating/trickling filters – Oxidation ponds – Activated sludge – Anaerobic digestion All of these use microbes. Q. Suggest why release of untreated waste water might result in oxygen depletion in the receiving water. – Untreated sewage contains organic waste and is food for microbes. Microbes use the waste, grow rapidly and consume O 2 in their respiration. Waste water is sprayed on the percolating filter – microbes in the filter remove the majority of soluble organic matter.

18. Larger bits of waste sink to the bottom of the sedimentation tank. The sediment goes to anaerobic digesters. The water containing soluble organic waste goes to the percolating filter, oxidation pond or activated sludge process. Waste water is sprayed on the percolating filter. Microbes form a biofilm and consume most of the organic waste, so that the effluent has a low biochemical oxygen demand (BOD) and can be safely discharged.

19. Copper Extraction The bacterium Thiobacillus ferrooxidans has been used to improve copper recovery from mine tailings and low grade chalcopyrite ore. – Oxidises sulphur in the chalcopyrite CuFeS 2 +2Fe 2 (SO 4 ) 3 +2H 2 0+3O 2  CuSO 4 +2H 2 SO 4 +energy – Copper then extracted by reacting with iron CuSO 4 +Fe  Cu+FeSO 4 Q. Suggest advantages of using ‘microbial miners’ to extract copper, rather than using traditional techniques. – Traditional techniques costly (energy requirements) and not efficient (hence relatively large quantities in the mine tailings). Microbes much more cost effective – lower grades profitable. Copper can be extracted from ore (chalcopyrite) using ‘microbial miners’.