1 history of biotechnology 2 food production microorganisms have been used to produce foods like:...

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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