F. Classification of Microorganisms - Bacteria

Bacterial Classifications

• Low/High G+C contents

• Deeply branching

• Gram (-) bacter (other ones too)

Deeply branching

• Live in environments closely related to early earth

• Hot

• Acidic

• Anaerobic

• High UV

• Autotrophic

Aquifex pyrophilus

• Chemoautotroph

• Hyperthermophilic

• Anaerobic

List of Deeply Branching/ Phototrophic bacteria

– P. Aquificae

– C. Aquifex

– P. Deinococcus-Thermus

– C. Deinococci

Phototrophic Bacteria

• Autotrophic

• phototropic that contain photosynthetic lamellae

Phototrophic Bacteria 4 Phyla

• P. + C. Cyanobacteria

– Blue-Green bacteria

• P. Chlorobi + C. Chlorobia

– Green sulfur bacteria

• P. + C. Chloroflexi

– Green non-sulfur bacteria

• P. Proteobacteria

– C. g-proteobacteria

» Purple sulfur bacteria

– C. a-proteobacteria

» Purple non-sulfur bacteria

Cyanobacteria - Blue/Green Bacteria

• G-

• ↑↑morphology variation

• Binary Fission

• Chlorophyll —> Oxygenic

• Transformed early earth atmosphere

• Few N-fixers

– Heterocysts

Green and Purple

Bacteriochlorophyll —> anoxygenic

Purple

Proteobacteria

Bacteria G+C Ratio - Low List

• P. Firmicutes

– C. Clostridia

– Bacilli

• Listeria

• Lactobacillus

– Cocci

• Streptococcus

• Enterococcus

• Staphylococcus

• P. Tenericutes

– Mycoplasma

Clostridium

Gram Positive

• Rod-shaped

• Obligate anaerobes

• Endospore-capable

Clostridium Impact

Medical/ Industrial = Survival

• Disinfection/ harsh conditions

Mycoplasma

• No cell walls (pleomorphic (shape shifter) | organelle tip)

• smallest free-living cells

• Facultative/obligate anaerobes

Mycoplasma

Impact

• Medical

UTIs/ Pneumonia

Other Bacilli

• B. thuringiensis

– Bt toxin x Caterpillar pests

– Hypothermic-resistant

• Milk + meat

Lactobacillus spp.

– Mucosal surfaces

– Symbiosis + Microbial antagonism

– Food industry

• Enterococcus

– Pathogenic

– MDR

High G+C Ratio - • P. Actinobacterium (Actinomycetota)

Corynebacterium

Corynebacterium

• Pleomorphic

• Facultative/obligate anaerobes

• Phosphate inclusions

• Snapping division (palisades - side by side)

Mycobacterium (High G+C)

• Rod shaped

• Aerobic

• Slow growth (cell wall | mycolic acids)

Mycobacterium (High G+C)

• Cell wall (mycolic acids)

• desiccation resistant

• Stain resistant (acid-fast stain)

Actinomycetes (High G+C)

• Spore-forming (non-reproductive)

• Filamentous (long strings)

Classes

• Actinomyces

Actinomycetes (High G+C)

Nocardia

• Water/Soil aerobes

• Biodegraders

– Streptomyces

• Ecological impact

– Cellulose, latex, PCBs,pesticides

• Medical generators

– CAM, ERY, TET

Gram- Negative Proteobacteria

• Gram (-)

• Chemoautotrophs

Classes

• αβγδε

C. Alphaproteobacteria

• low nutrient survivors

• industrial application

• may have prothecae (outside protection)

C. Alphaproteobacteria

Nitrogen fixers

• growth associated with palnt roots

• N2 —> NH3 (fixed)

C. Alphaproteobacteria - Rhizobium (Genus)

• Leguminous roots

• Induce root nodules

• Growth sitmulant

C. Alphaproteobacteria - Azospirillum (Genus)

Tropical grass roots

– Increase root hair