MICROBIOLOGY

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MICROBIOLOGY

• From foukeffa.org
• Written by Teri Micke
• Ag Student Texas AM
• GA Ag Ed Curriculum Office
• To accompany the Georgia Agriculture
  Education Curriculum Course 02431
• July 2002

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FOOD MICROBIOLOGY

• study of how microbes affect food

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SUBSTRATE

• substance consumed by microbes (food it eats)

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TYPES OF MICROBES

• 1. Mold
• also called fungi
• fuzzy, cottony - easy to see
• cells grow end to end to form hyphae, a group
  of hyphae is called mycelium

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MOLDS (cont.)

• require little water, grow on foods with low
  aw
• need oxygen to grow - aerobic
• 3 types 1. mesophiles - room temp
• 2. psychrophiles - cold temps
• 3. thermophiles - high temps
• multicellular

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TYPES (cont.)

• 2. Yeast
• unicellular
• Why do breads rise?
• yeasts convert sucrose into CO2 and water
• aerobic or anaerobic

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• 3. Bacteria
• reproduce by fission-cell splitting
• encapsulation-form hard shell to survive
  hostile environments

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Bacteria (cont.)

• heterotrophic - can use anything for substrate
• aerobic or anaerobic - some are both
• great tolerance of aw and pH
• examples salmonella, E.Coli, listeria

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• 4. Viruses
• structure protein coat surrounding DNA/RNA
• require no nutrients only genetic material
• example Hepatitis A, Polio