MICROBIOLOGY From foukeffa.org Written by Teri Micke Ag Student Texas A&M GA Ag Ed Curriculum Office To accompany the Georgia Agriculture Education Curriculum Course July 2002

FOOD MICROBIOLOGY l study of how microbes affect food

SUBSTRATE l substance consumed by microbes (food it eats)

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

MOLDS (cont.) require little water, grow on foods with low a w need oxygen to grow - aerobic 3 types: 1. mesophiles - room temp 2. psychrophiles - cold temps 3. thermophiles - high temps multicellular

TYPES (cont.) 2. Yeast unicellular Why do breads rise? yeasts convert sucrose into CO 2 and water aerobic or anaerobic

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

Bacteria (cont.) heterotrophic - can use anything for substrate aerobic or anaerobic - some are both great tolerance of a w and pH examples: salmonella, E.Coli, listeria

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