Transcript History of Biotechnology

History of
Biotechnology
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Food Production
Microorganisms have been used to
produce foods like:
yogurt, cheese, rootbeer, wine
Came 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 thermophilus
Lactobacillus 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
Metabolite
At 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 Metabolite
Alexander 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 vaccines
Die 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
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