Biotechnology 3 Flashcards
Gather and process information from secondary sources to:
- Identify and describe a named industrial fermentation process
- Identify the micro-organisms used in the fermentation and the products of the fermenation
- Outline the use of the product of the fermentation process
- Use available evidence to assess the impact of the use of the fermentation product on society at the time of its introduction
INDUSTRIAL PROCESS
Glycerol was initially isolated and refined as a byproduct of the manufacture of soap from animal fats.
Glycerol is created when a metabolic pathway in yeast fermentation is stopped by the addition of inhibitor sodium sulfite (Na2SO3). This process however became more expensive during the 20th century, forcing scientists to develop alternative methods. In WWI, glycerol was a blocked resource to Germany, forcing German biotechnologists to modify the fermentation process.
Propylene (a product of petroleum) is used to alternatively produce glycerol but it has become a more expensive and scarce resource over time. The fermentation of sugar is growing in popular again as it is more accessible and environmentally friendly. Advancements in technology has also improved this process with the selection of strains of yeast which grow efficiently in the thick, syrup-like, viscous liquid that develops as glycerol accumulates.
MICRO-ORGANISM
Saccharomyces cerevisiae (yeast) on sugar. Sodium sulfite is added as it ferments.
PRODUCTS OF FERMENTATION
- ethanol
- glycerol
- carbon dioxide
The addition of sodium sulfite increases glycerol production by 20-30%.
USES OF PRODUCT
Alternatively called glycerine, glycerol is used in a range of cosmetics, skin preparations and soap substitutes. Its non-toxicity allows it be used in confectionary and liquid medicines.
Industry glycerol has use in the manufacturing of plastics, explosives, paints and inks. It is also used as a lubricant in machinery and food products.
Its antifreeze properties allows glycerol to be used in scientific research and medicine, storing frozen living cells/tissues for later use and prevents ice crystals from destroying the cells when it is thawed.
IMPACT OF THE USE OF THE PRODUCT
Glycerol has become an important resource for both commercial and industrial processes and products. It has led to the development of various consumer products which have become common household items - e.g. cosmetics and soap - and sweet foods.
It was alternatively a dangerous ingredient for explosives in WWI.
Glycerol is affordable and environmentally friendly when produced from sugar fermentation.
Describe the expansion of fermentation since the early 18th century to include the production of several organic compounds, including glycerol, lactic acid, citric acid and yeast biomass for baker’s yeast.
Since the early 18th century, advancements in biology and fermentation and distillation made it possible to produce alcohol on a cheaper scale. Further advancements over the next two hundred years allowed for organic compounds to be fermented using different carbohydrates and micro-organisms, producing glycerol, lactic acid, citric acid and yeast biomass.
The Industrial Revolution significantly impacted this development. Pressure to improving manufacturing processes like fermentation to fit new forming lifestyles.
During the 19th and 20th centuries, it was observed that different growth mediums/conditions for different strains of micro-organisms would produce different products. This led to the improvement fof the separating and purifying of these products.
The need for a sterile working environment and chemical analysis improved, as well as instruments such as the micro-scope and balancetx, also improved over time. This allowed scientists to observe the role of micro-organisms in the industrial process. Improved fermentation techniques and control over the isolation and purification of various products enabled larger quantities at better qualities of food to be manufactured.
Today, technological advancements such as genetic engineering has allowed for further control over what products are produced and how e.g. elimination of pollutants and the production of a particular product.
Glycerol was formed by adding sodium bisulfate to the fermentation of sugar. It is used as a solvent, a sweetener, antifreeze mixtures, medicine and dynamite.
Lactic acid is produced by the fermentation of milk sugar lactose by various types of bacteria to produce products such as cheese and yoghurt. Lactic acid fermentation is used to produce yoghurt, buttermilk and cultured milk. Propiomic acid fermentation produces Swiss cheese.
Lactic acid is also used in medicine, textile dyeing, leather tanning and plastics.
Citric acid is produced using the fungus Aspergillus niger on the submerged fermentation of glucose. It is used as a flavour enhancer.
Yeast biomass (baker’s yeast) uses selected strains of Saccharomycies cerevisiae, developed by the end of the 18th century. Previous to this, brewer’s yeast was used to produce bitter bread.
Describe strain isolation methods developed in the 1940’s.
Strain isolation methods began to be developed to further improve the quality and quantity of the products created from micro-organsisms.
Pasteur and Koch had already developed some basic isolation techniques, but the necessary laboratory and industrial methods - microscopy, sterilisation and safe equipment - for individual strains to be efficiently isolated and cultured wouldn’t be developed until later.
- sanitation methods e.g. Sterilisation by flaming or disinfecting equipment or using UV light
- sterile stainless steel
- improved glassware
- reliable energy sources
- improved communication and collaboration
- better chemicals
- laminar flow cabinet: sterile air constantly flowing in
Strain isolation allowed scientists to identify colonies or individual organisms which had valuable properties to use. A series of subsampling and incubation of microorganisms on agar plates is used, where a small sample is transferred onto a new sterile agar plate until individual colonies of strains are evident.
Describe, using a specific example, the benefits of strain isolation methods used in biotechnology in the 20th century.
Penicillin was first discovered by Alexander Fleming in Britain, 1928. It was proven by Howard Florey and Ernst Chain between 1939-42 to be non-toxic in humans and effectively acted on a wide range of pathogens.
By 1940, Penicillin was isolated from the strain Penicillium notatum by Norman Heatley. The US gov offered facilities and financial assistance in Peoria, Illinois, to help produce it as an antibiotic in large quantities. Further research into more effective strains of Penicillin were also made using strain isolation methods.
The most successful strain was provided from the mould growing on a melon by a local, Mary Hunt. Dr Heatley and the American staff were able to isolate this strain - it produced 8gm/L. Subcultured strains of the same mould eventually led to the discovery of a production capacity 1000 times greater than before.
Improved conditions for production such as stainless steel tanks allowed for experimentation on nutrition and additives on even greater scale.
By the end of 1945, penicillin could be produced for all the wounded Allied troops in Europe.
Fleming, Florey and Chain later won the Nobel prize their work.
Process and analyse information from secondary sources to demonstrate how changes in technology and scientific knowledge have modified traditional uses of biotechnology, such as fermentation.
Early traditional fermentation practices were not completely understood by humans until thousands of years later. It was only observed that particular foods changed over time in storage - fruit juice to wine, raised bread, and curdled and soured milk (cheese). Hence, with only the basic technology available, the means to continue the fermentation practice were only available to early peoples.
- starter samples from successful batches for new batches
- additives e.g. sugar to dough
- particular conditions e.g. warm storage
