Classification of Bacteria

Macroscopic Appearance Color - pigment produced by bacteria

Macroscopic Appearance Texture - may be gloss, stringy, smooth, dull, dry & powdery, etc. Other: shape, size, elevation, odor, etc.

Shape - Primary Classification Cocci (coccus) = spherical

Shape - Primary Classification Bacilli (bacillus) = rod shaped

Shape - Primary Classification Sprilla (spirillum) = spiral shaped

Arrangement Diplo- = pairs of bacteria Strepto- = chains of bacteria Staphylo- = clusters of bacteria Tetra = groups of four bacteria Sarcinae = groups of eight bacteria

Arrangement

Arrangement

Response to Gram Stain Determined by the biochemistry of the bacterial cell wall Gram+ bacteria = purple Gram- bacteria = reddish-pink *medically important test to identify bacteria

Response to Gram Stain

Other Methods of Classification Nutrition Oxygen requirements Other unique features: pili, capsules, endospores, or flagella

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