• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Nobody had ever seen microbes or even thought they might exist because microbial effects could be explained in other ways.

Extracts from this document...


Microbes. Nobody had ever seen microbes or even thought they might exist because microbial effects could be explained in other ways. What we now call biotechnology probably began as a kind of magic 1000's of years ago. It took a huge leap into turning into a science in the 1670s when a Dutch microscope maker called Anton van Leeuwenhoek looked at a sample of his own saliva. Factors that affect the growth of microbes are called limiting factors and influence the growth of cells in culture: - nutrient availability, temperature, pH, oxygen and build up of toxic material. An unfavourable level of any one of these factors can slow them to slow down or stop growth. Commercial Biotechnology. The commercial production of microorganisms used to be by batch culture - a culture was set up and after a period of growth it was harvested. A more recent method that has been used to grow the organisms in continuous culture - along-term operation over many weeks, during which time nutrient medium is added as fast as it is used and the overflow is harvested. Biotechnology is the use of biological agents to produce or process some other material. ...read more.


Selecting a strain. Enzymes are only produced by living cells and microorganisms are used to produce enzymes on an industrial scale. The scope for detecting new and useful organisms is huge. E.g. 10's of millions of microorganisms of many different types exist in a gram of soil. Less than 1% of the world's microorganisms have been researched so there is much more scope for research. Strain selection is necessary to find the microorganisms that will produce an enzyme that will do exactly what is required. Strains must therefore not make humans ill; some could be genetically altered. Organisms that are selected to produce the enzymes that are used in the food industry have to comply with very strict rules and regulations. The responsibility of the final product's safety lies with the product manufacturer. Intracellular and Extracellular enzymes. The enzymes are always produced inside the cells but many pass out through the cell walls into the growth medium. These are known as extracellular enzymes. Enzymes that stay within the cell are known as intracellular enzymes. Most of the enzymes that are used in industrial applications are extracellular enzymes produced by microorganisms during fermentation; the process can be either using a submerged or a surface culture. ...read more.


contact with protein that it can break down into amino acids for the bacterium to absorb - so each bacterium is producing more enzyme in order to maximize the harvest of amino acids from the small amount of protein that is available. If the organisms are given too little nutrients then they will not survive at all. The biotechnologists provide a medium that contains just sufficient nutrient to ensure that the microorganisms in the main fermenter produce the maximum amount of enzyme and continue to grow without increasing the number of cells. This stage of population growth is called the exponential growth phase and it is the production phase of the fermentation. It is also important to control the other growth factors e.g. oxygen level, pH and temperature are also monitored and controlled. Maximum enzyme production is achieved when each of the growth conditions is maintained at its optimum. Enzyme production is more efficient today than 100 years ago as: - * Genetic manipulation of microorganisms has improved yields; * Low-cost nutrients and advanced monitoring have improved fermentation technology; * New methods extract a greater proportion of the enzymes from the cell; * Down stream processing techniques are more efficient; * Continuous production in special reactors is more efficient than batch processes. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Molecules & Cells essays

  1. Marked by a teacher

    How does the concentration of enzymes affect the breakdown of starch by a-amylase in ...

    4 star(s)

    Repeat this for all the concentration solutions, using a clean pipette for each different concentration. If this method were to have been followed, there would have been a much smaller discrepancy in the measurement errors of the concentration solutions, resulting in much more accurate results.

  2. A2 coursework- The effects of bile salts on digestion of fat

    lines start to level out and there is not such a big decrease in pH as there was at the beginning of the reaction. This could be due to a number of factors. At the beginning of the reaction there is maximum amount of substrate and maximum amount of enzyme

  1. Growing Micro-organisms

    test, this will agitate the solution and the process will quicken, you could also keep providing the yeast population will oxygen because the oxygen acts as an catalyst and speeds up the process. The Factors that will affect the growth of the yeast cells are as followed: * Temperature: -

  2. Follicular development

    2003 Activin signaling pathways in ovine pituitary and LbetaT2 gonadotrope cells. Biology of Reproduction 68(5):1877-1887 Grieshaber NA, Boitano S, Inhae JI, Mather JP, and Tae HJI. 2000. Differentiation of Granulosa Cell Line: Follicle-Stimulating Hormone Induces Formation of Lamellipodia and Filopodia via the Adenylyl Cyclase/Cyclic Adenosine Monophosphate Signal.

  1. Enzymes and Micro-organisms

    So this is why growth media is needed. Growth media is a specific media that can only facilitate that specific microorganism and so therefore all other unwanted microorganisms will be suppressed. Only the best microorganisms are isolated from a populationand then the best generation is cultured to present a microorganism on its own.

  2. The costs of cigarette smoking

    Recent research indicates that passive smoking kills about 106,000 Europeans each year, making it the third leading cause of preventable death after direct smoking and alcohol abuse7. While one quarter of European adults smoke, the problem affects everyone. In 1993, physicians who looked at nicotine levels in the blood were

  1. The Application of Enzymes in Industry and Medicine.

    There has even been a company set up to investigate pharmaceutical manufacture, for the use of enzymes. Enzymes are even used to aid digestion, in humans and animals. They are used to supplement natural amylase, lipase and protease produced by the pancreas.

  2. Describe the evolution of microbes.

    The most widely accepted hypothetical scenario is that the first organisms were the products of a chemical evolution and occurred in four stages 1. Abiotic synthesis and accumulation of monomers such as nucleotides and amino acids (small organic molecules that are building blocks).

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work