Bacterial Microbes of Note

PHYLUM: Proteobacteria

the largest group of Gram Negative

has 6 classes

• Alpha

• Beta

• Gamma

• Delta

• Epsilon

• Zeta (not mentioned as much)

ORDER: Enterobacteriales

• Gamma Proteobacteria

  • gram negative

• facultative anaerobes

• includes coliforms (which indicate fecal contamination

species examples: salmonella, shigella, eschericia

CLASS: Pseudomonales

• Gamma Proteobacteria

  • gram negative

• obligate aerobes

• psychrophilic

• degraders

pseudomonas

GENUS: Vibronales

• curved/ comma shaped

• fish and fish-borne diseases

V. cholerae and V. parahaemolyticus

GENUS: Rhizobium

• Alpha Proteobacteria

• converts N₂ to

• ammoniaanaerobic

forms symbiotic relationships with plants, attaching to roots within nodules (forming BACTERIODS) providing fixed nitrogen to the plant and getting sugars and an anaerobic environment from the plant root

development of the a nodule depends on chemical dialogue between bacteria and root cell (specific species interact)

GENUS: Nitrosomonas

Alpha Proteobacteria

converts ammonia to nitrite

GENUS: Nitrobacter

Alpha Proteobacteria

converts nitrite into nitrate

GENUS: Agrobacterium

Gram Negative

transfer DNA to plant cells

GENUS: Rickettsia

• Gram Negative

• obligate cellular parasites

• arthropod vectors

• rocky-mountain spotted fever

GENUS: Acetobacter

• Gram Negative

• converts ethanol into vinegar

• a type of acetic acid bacteria

GENUS: Wolbachia

• Gram Negative

• only infects invertebrates

GENUS: Thiobacillus

• Beta Proteobacteria

  • gram negative

• assimilates inorganic sulfur into sulfate

GENUS: Zooglea

• Beta Proteobacteria

  • gram negative

• aerobic

• breaksdown sewage

  • vital to water-treatment

GENUS: Neisseria

• Beta Proteobacteria

  • gram negative

• can invade and live in neutrophils

N. meningitidis and N. gonorrhoeae

GENUS: Bordetella

• Beta Proteobacteria

  • gram negative

• whooping cough

B. parapertussis

GENUS: Desulfovibrio

• Delta Proteobacteria

  • gram negative

• uses sulfate as terminal electron acceptor

• aquatic sulfur reducer

sulfur cycle

GENUS: Campylobacter

• Epsilon Proteobacteria

  • gram negative

• poultry borne food poisoning

C. jejuni

GENUS: Helicobacter

H. pylori → peptic ulcers

PHYLUM: Firmicutes

the largest group of Gram Positive

4 important orders

• Bacillales

• Lactobacillales

• Clostridiales

low G+C

GENUS: Bacillus

• Bacilliales

  • gram positive

• endospore forming (1/2)

B. anthracis B. cereus B. thyringrensis

GENUS: Staphylococcus

• Bacilliales

  • gram positive

• irregular clusters

• salt tolerant

S. aureus (VRSA and MRSA)

GENUS: Listeria

• Bacilliales

  • gram positive

• serious food-borne infections

• in prepared meats and shelfish

GENUS: Lactobacillus

• Lactobacilliales

  • gram positive

• lactic acid → probiotic?

GENUS: Streptococcus

• Lactobacilliales

  • gram positive

• haemolysis is common with this genus

GENUS: Clostridium

• Clostridiales

  • gram positive

  • strict anaerobes

  • produce endospores

C. botulinum and C. tetani

GENUS: Clostridiales

• Clostridiales (order)

  • gram positive

  • endospore forming

  • obligate anaerobe

C. difficile

ORDER: Mycoplasmatales

• completely lack any cell wall

• often found to be pathogenic

  • not always human pathogen

• relatively small/ unexplored new classification

• facultative anaerobe

mycoplasma

Chlamydiia

a group that behaves like a virus, requiring a host for growth

GROUP: Cyanobacteria

• photoautotrophic

• gram negative

• found in extreme habitats

• facultative anaerobe

• nitrogen fixing

a group very important to oxygen production

2 important genera:

• Anabena

• Prochlorococcus

PHYLUM: Actinobacteria/Actinomycetota

• gram positive

• low in C+G

• spore-forming

GENUS: Mycobacteria

• Actinobacteria/Actinomycetota

• known to induce serious diseases in mammals

• mycolic acid in cell walls

  • unique long fatty acid chains

M. tuberculosis

M. leprae

Streptomyces

• the largest genus of the Actinobacteria/ Actinomycetota phylum

• very important soil degrader

• source of many antibiotics

  • the ‘mycin’ antibiotics

S. erythraeus

SPECIES: Corynebacterium diphtheriae

• gram positive

• aerobic

• non-spore forming

a toxin gene carried by a vrius must first infect the bacterium

PHYLUM: Spirochaetes

a group unique in shape and motility

have AXIAL FILAMENT held tightly to the cell wall by an Outer Sheath

move in a corkscrew motion

examples: Treponema pallidum and Borrelia burdorferi

PHYLUM: Bacteriodetes

• gram negative

• rod shaped

• anaerobe

• inhabit a large variety of ecosystems

• ruminants degrade cellulose

  • great for gut biome

Endophytes

unofficial classification of nonpathogenic bacteria that live between the cells of host plant tissue