Applied and Industrial Microbiology

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Chapter 28

• Applied and Industrial Microbiology

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Foods Disease

• Because we distribute food that was prepared in
  central facilities the chance of widespread
  disease is more likely.
• The USDA and FDA inspect these facilities to set
  standards for these facilities to prevent
  contamination.

• The earliest forms of food preservation were
  adding salt/sugar, fermentation, and drying.

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The Role of Microorganisms in Food Production
(MFP)

• CHEESE!
• The milk protein casein curdles because of the
  action by lactic acid bacteria or the enzyme
  rennin/chymosin.
• -Cheese is the curd separated from the liquid
  portion of milk, called whey

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MFP Cheese Continued

• 2. Hard cheeses are produced by lactic acid
  bacteria growing on the interior of the curd
• -growth of microbes in cheese is called ripening
• 3. Semisoft cheeses are ripened by bacteria
  growing on the surface

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MFP Other Dairy Products

• Old-fashioned buttermilk was produced by lactic
  acid bacteria growing during the butter-making
  process
• -commercial buttermilk is made by letting lactic
  acid bacteria grow in skim milk for 12 hours

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Sour cream, yogurt, kefir, and kumiss are
produced by lactobacilli, streptococci, or yeasts
growing in low-fat milk.
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MFP Nondairy Fermentations

• Sugars in bread dough are fermented by yeast to
  ethanol and CO2 the CO2 causes the bread to rise
• Sauerkraut, pickles, olives, and soy sauce are
  products of microbial fermentation

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MFP Alcoholic Beverages and Vinegar

• Carbohydrates obtained from grains, potatoes, or
  molasses are fermented by yeasts to produce
  ethanol in the production of beer, ale, sake, and
  distilled spirits.
• Sugars in fruits such as grapes are fermented by
  yeasts to produce wines

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Fermentation Technology

• Industrial Fermentation
• The large-scale cultivation of microbes or other
  single cells to produce a commercially valuable
  substance.
• Also used in biotechnology to obtain useful
  products from genetically engineered plant and
  animal cells.

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Fermentation Tech Industrial Fermentation

• Bioreactors
• Vessels for industrial fermentation and is
  designed with close attention to aeration, pH
  control, and temperature control.
• Sometimes very large and can hold up to 500,000
  liters.

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Bioreactors
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Fermentation Tech Metabolite

• Primary metabolite
• A product of an industrial cell population
  produced during the time of rapid logarithmic
  growth.
• Secondary Metabolite
• A product of an industrial cell population
  produced after the microorganism has largely
  completed its period of rapid growth and is in
  stationary phase of growth cycle.

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Fermentation Tech Strain Improvement

• Strain improvement is also an ongoing activity in
  industrial microbiology.
• A well-known example is that of the mold used for
  penicillin.
• The original culture of Penicillium did not
  produce penicillin in large enough quantities for
  commercial use.

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Industrial Food Canning

• Industrially canned goods undergo what is called
  commercial sterilization, by steam under pressure
  in a large retort which works like an autoclave.
• Commercial sterilization is intended to destroy
  C. Botulinum, because if that endospore is
  destroyed, then any other spoilage or pathogenic
  bacteria will also be destroyed.
• The 12D treatment is used to decrease the amount
  of C. Botulinum by 12 logarithmic cycles (1012).
  This treatment is considered safe because if
  there were 1,000,000,000,000 endospores in a can,
  there would be one survivor after the 12D
  treatment.
• Thermophilic anaerobic spoilage is a fairly
  common cause of spoilage in low-acid canned
  foods. The can usually swells from gas, and the
  contents have a lowered pH and a sour odor.
• When thermophilic spoilage occurs and the can
  isnt swollen by gas production, the spoilage is
  called flat sour spoilage.

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Radiation and industrial food Preservation.
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• Food can be sterilized completely by radiation.
• The food sterilized by this method doesnt become
  radioactive.
• The taste of certain foods change after using
  radiation to sterilize it.
• Irradiation treatment RESEMBLES PASTEURIZATION
  BY HEAT TREATMENT.
• Using radiation on food kills parasitic worms,
  insects, and fruits and vegetables dont sprout.
• The kind of radiation used on food is cobalt-60.

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Aseptic Packaging The Future of Industrial
Microbiology

• Chapter 28

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Aseptic Packaging The Future of Industrial
Microbiology

• Packages are usually made of materials that are
  tolerant to conventional heat treatment
  (laminated paper or plastic)
• The packaging materials came into continuous
  rolls that are fed into a machine that sterilizes
  the material with hot hydrogen peroxide solution-
  sometimes aided by ultraviolet light.
• Metal containers can be sterilized with
  superheated steam.
• While still in the sterile environment, the
  material is formed into packages, which are
  filled with liquid foods that have been
  sterilized by heat.

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Industrial Products

• Chapter 28

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Amino Acids

• lysine and methionine are amino acids that cannot
  be synthesized by animals.
• In nature, microbes only produce the amount of
  amino acids needed. No excess will be made due to
  feedback inhibition.
• Commercial amino acid production occurs in a lab
  where the microbe is manipulated to create more
  amino acids to be used.

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Citric Acid

• Citric Acids are in fruits such as lemons and
  oranges.
• Citric Acid gives tartness to foods, serves as a
  pH adjuster and antioxidant. In dairy, it serves
  as an emulsifier.
• Most commercially produced citric acid is
  produced by the mold, Aspergillus niger.

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Enzymes

• The production of amylases was the first
  biotechnology patent given by the U.S.
• Enzymes are used in manufacturing foods,
  medicines and other goods that microbes produce.

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Vitamins

• Vitamins are tablets that are used as food
  supplements.
• Most microbe species produce the majority of
  vitamins people take.

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Pharmaceuticals

• Most antibiotics were originally produced by
  microbes. Today, we can also synthetically
  produce antibiotics.
• Vaccines are made by means of industrial
  microbiology.
• Steroids can also be synthesized by
  microorganisms.

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Copper Extraction

• The metabolic activity of Thiobacillus
  ferrooxidans is used to recover uranium and
  copper ores
• An ore is a metal-bearing mineral or rock
• Thiobacillus gets its energy from the oxidation
  of a reduced form of iron. This energy is used to
  recover copper ores.

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Microbes as Industrial Products

• Some microbes are purposefully produced in mass
  amounts to be used in production.
• For example S. cerevisiae or (Bakers yeast) is
  produced in large fermentation tanks.
• After, the yeast is packaged into yeast cakes to
  be sold for baking at home.

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Alternatative Energy Sources Using Microorganisms

• Organic waste, called biomass, can be converted
  by microorganisms into alternative fuels, a
  process called bio conversion.
• Examples of fuels produced by microbial
  fermentation are methane and ethanol.