Bacterial Identification

1. E. Coli

• Gram negative rods• Harmless but a few are

pathogenic• Strains 0157:H7 causes

food illnesses• Normal bacterial flora in

lower intestines of warm blooded animals

Sarcina aurantiaca

• Orange pigments• Gram +• Anaerobic• Appears in cuboidal

masses• Usually harmless • Found in air and water

Bacillus subtilis

• Gram + obligate aerobe• Tough endospores• Can contaminate food,

but rare to cause illness

• Enzymes used in laundry detergent

• Natural fungicide

Micrococcus roseus

• Gram + • Skin: transforms

compounds in sweat into compounds with an unpleasant odor

• animal and dairy products, and beer.

• water, dust, and soil.

Bacillus megaterium

• Gram + rods• Endospores• Found in soil/forms

spores• Used to produce

penicillin amidase

Micrococcus luteus• Gram + cocci• Normal flora of upper

RT and mouth• Mammal skin• Opportunistic

pathogen

Staphylococcus epidermis

• Gram + diplococci• Catalase +• Opportunistic pathogen– Harbor around plastic

medical equip: heart valves, catheters, IVs

Streptomyces violaceus

A model organism• Gram + rods• Produces violet pigments• New research: antibacteria

and antiviral activities

Serratia marcescens D1• Gram – rods• Human pathogen of Respiratory

and UT– UTI and catheter infections

• Produces red pigment: prodigiosin

• Found in restrooms; grows well in tile grout and shower curtains

Streptococcus lacti

YUM!• Gram + cocci in short chains• Production of buttermilk,

cheese (brie, camembert, colby)