1 history of biotechnology 2 food production microorganisms have been used to produce foods like:...
TRANSCRIPT
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History of Biotechnology
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Food Production
Microorganisms have been used to
produce foods like: yogurt, cheese, rootbeer, wineCame about by accident: No knowledge of food preservation Moist foods became contaminated
with bacteria, yeast, and molds
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Production of Yogurt Commercial yogurt = fermented
dairy product made by action of two bacteria:
Streptococcus thermophilusLactobacillus bulgaricus As bacteria metabolize sugar, they
produce acid causing the casein(protein) to coagulate
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Food Production and Bioprocessing
In the production of yogurt, biomass is what is harvested
Biomass = total dry weight of all organisms in a sample or population
In the production of wine or other foods, it is the metabolite you are harvesting
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Metabolite = substance (excreted during) involved in metabolism
Primary metabolite = excreted during growth phase
Secondary metabolite = excreted during the end of growth phase or during secondary phase
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Bacterial Growth Curve Lag Phase – number of cells
change very little because the cells do not immediately reproduce in a new medium; cells ar synthesizing DNA and enzymes
Log Phase – cells begin to divide and enter a period of growth; logarithmically increases; cellular reproduction is most active
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Stationary Phase – exhaustion of nutrients, accumulation of waste products and harmful changes in pH cause the colony to stabilize
Death Phase – number of deaths exceeds the number of new cells formed; logarithmic decline
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Wine Production: Harvesting a Primary MetaboliteAt first it was not known that
microorganisms aided in alcohol production
Louis Pasteur brought this to light:1. Yeast converts sugar to alcohol-in
the absence of air (fermentation)2. Souring-occurs when bacteria
convert alcohol into vinegar(acetic acid)
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Pasteur suggested heating the alcohol enough to kill microorganisms (pasteurization)
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Antibiotic Production: Secondary MetaboliteAlexander Fleming (Penicillium
notatum)
Discovered penicillin by accident
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Original strain only produced 2mg of penicillin per liter of culture fluid; scientists isolated cultures to develop a strain that produced over 20g./l.
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Industrial Uses of Plant and Animal Cell Cultures
Animal Cell Cultures:Used in production of vaccinesDie out after several generations
(except for tumor cells)Hybridoma=hybrid, fusing a myeloma
(tumor) cell with lymphocytes(white blood cells) to grow indefinitely
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Plant Cells
Whole plants serve as sources of agricultural chemicals, drugs, flavoring, and coloring
Plant Regeneration
Plants developed from single cells:
Produce many plants with less effort
Virus free cells can be isolated to produce virus-free crops
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Proliferation – cell growth
Apoptosis – programmed cell death
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What does the future hold?
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In the 1980’s Biotechnology grew due to the development of recombinant DNA technology
Ex. Human insulin grown by bacteria
Today the focus is on RNA as well as DNA
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The End