EXAM 3: Gram-negative Non-proteobacteria_19.pdf

Phylum Aquificota -Hyperthermophiles

• Genus Aquifex "makes water"

• Chemolithoautotrophs : "eat rocks"

-Oxygen as terminal electron acceptor

-Oxidize H, thiosulfate, sulfur

-Fix carbon dioxide with reductive TCA

• Hyperthermophiles: Temperatures between 85°C and 95°C

Phylum Thermotoga - Hyperthermophiles

• Hyperthermophile: Optimal at 80°C, max 90°C

• Rods with outer sheathlike envelope (extends, balloons from cells)

• No LPS in outer membrane

• Marine hypothermal systems (geothermal areas) and solfateric springs (volcanic vent)

• Chemoorganotrophs: glycolytic pathway, use ferric iron, sulfur as terminal electron acceptors

Phylum Deinococcota

Deinococcus radiodurans

•More resistant to radiation than endospores

-3-5 million rads of radiation (100 lethal to humans)

-ROS can damage macromolecules

-Have protection mechanism against ROS oxidation

• Spherical, rod-shaped; in pairs, tetrads

• Nonmotile

• Aerobic heterotrophs

• Stain Gram-positive, but have outer membrane with LPS

Phylum Deinococcota-Thermus aquaticus

• Found in a hot spring in Yellowstone National Park

• Grows optimally 70°C

• Thermostable enzymes

-Source of Taq polymerase (PCR)

Phylum Bacteroidota - Green sulfur bacteria

• Green sulfur bacteria in anoxic sulfide rich lakes

• Example Genera: Chlorobium, Prosthecochloris, and Chlorobaculum

• Obligate anaerobic photolithoautotrophs

• Use hydrogen sulfide, sulfur, and hydrogen as electron sources

• Chlorosomes: vesicles with lipid monolayer attached to PM with photosynthetic pigments (bacteriochlorophyll)

- Transfers light to reaction centers in PM

- ATP produced from photophosphorylation

- Carbon dioxide fixation from reductive TCA

Phylum Bacteroidota - Gut microbiota

• Genus Bacteroides

• Chemoheterotrophs

• Animal rumens, human digestive tract

• Human symbionts (help digest glycans like cellulose, agar, chitin)

-Provides nutrients

• B. fragilis : "double-edged sword"

-Helpful: assist digestion, regulate immune system, restore "normal" behavior in autism mice model

-Harmful: Abdominal, pelvic, pulmonary, and blood infections (if overgrowth); overabundance with autism

• Type V pili to attach to surfaces (gut, oral mucosa)

Phylum Chloroflexota : Green non-sulfur bacteria

• Chloroflexus genus

• Green nonsulfur bacteria • *Not all green, some use sulfur

• Filamentous, gliding

• No outer membrane

• Chlorosomes with PM

• Metabolically diverse

• bacteria that are photosynthetic but not oxygenic

• Don't produce oxygen

Phylum Cyanobacteria

• Obligate photolithoautotrophs

• oxygenic photosynthesis: use chlorophyll a, PSI, PSII

• Thylakoid membranes: ETC components, light harvesting

• Largest, most diverse photosynthetic bacteria group

• Phototaxis with gas vacuoles

• Fix carbon dioxide with CalvinBenson cycle in carboxysomes

• fix nitrogen with heterocysts

• impt to environment (producers of oxygen)

• Endosymbiotic cyanobacteria evolved into chloroplasts

Phylum Planctomycetota

• Genus Planctomyces

• Chemolithoautotrophs: ammonium electron donor, nitrate terminal electron acceptor

• Ammaxosome: membrane bound organelle for anaerobic ammonium oxidation; single layer of lipids (ladderane)

• Contributes 70% to cycling of Nitrogen to oceans

• found in aquatic environment

Phylum Verrucomicrobiota - Gut microbiome

• Akkermansia municiphila • Makes up 1-5% of gut microbiome

• Consumes mucus

• Lack associated with metabolic disorders: obesity, diabetes, intestinal inflammation, cancer

• Obligate anaerobe

• Fermentation

• Nonmotile

• Coccobacillus

Phylum Verrucomicrobiota

• Chlamydiae includes Genera Chlamydia and Chlamydophila

• no peptidoglycan

• intracellular parasite: must grow, reproduce in host cells (animal cells, protists)

• Unique reproduction: elementary body, attaches to host surface, reorganizes of host actin to enter with endocytosis, reside in inclusion bodies; hijack golgi; differentiate into reticulate body

Phylum Verrucomicrobiota - Chlamydial pneumonia

• Human/animal pathogens:

• Chlamydial pneumonia

-Chlamydophila pneumoniae

-"round pneumonia"

-EBs inhaled, spread by droplets

-Pharyngitis, bronchitis, sinusitis

Phylum Verrucomicrobiota - Psittacosis

• Human/animal pathogens:

• Chlamydophila psittaci

• Psittacosis (ornithosis), associated with birds, people in contact with birds

• Zoonatic disease

• Inhaled in respiratory tract • Transported to liver and spleen, multiply and move to lungs

-Inflammation, hemorrhaging, pneumonia

-Endocarditis, hepatitis, neurological issues

• 50 cases in US each year

Phylum Verrucomicrobiota - Chlamydia STD

•Chlamydia

• Chlamydia trachomatis

• Most reported bacterial STD

• Some no symptoms

• Transmitted: anal, oral, vaginal, vaginal birth

• Inflammation of reproductive structures

• Pelvic inflammatory disease

• During pregnancy: related to stillbirth, miscarriage, conjunctivitis, pneumonia in infant

Phylum Spirochaetota

• Corkscrew

• Chemoorganotroph

• coiled morphology, like spirillum, but axial filaments (flagellum under the "skin")

• Spirochaeta genus: aquatic, free-living

Phylum Spirochaetota Treponema pallidum (syphilis)

• Motile, enters through mucous membranes

• STD: transmitted from contact with infected lesion

• Symptoms depend on stage

-Primary: ulcer (chancre)

-Secondary: variable skin rash

-Latent: not infectious (except mother to fetus)

-tertiary: gummas (fibrous tissue) in skin, bone, NS (cognitive defects; blindness; shuffling; insanity)

• Antigenic variation (evades immune system)

Tuskegee Study

• 1932-1972 Macon County, Alabama

• Federal Public Health Service "study" on 600 black men to develop syphilis treatment

-399 with syphilis

-201 without syphilis

• Provided with free medical checkups, meals

• Patients in study were not informed on what study was on

• Penicillin treatment withheld from these men even after mass production 1947

• Participants won class action lawsuit 1974; wives and children added 1975

Phylum Spirochaetota-Borrelia burgdorferi

(lyme disease)

• Arthropod-borne transmission (tick)

• Around 30,000 confirmed cases/year in US

• Phase variation

• Stage 1: Erythema migrans (expanding ring-shaped lesion) with flu-like symptoms

• Stage 2: neurological, inflammation, arthritis

• Stage 3 (years later): neuron demyelination (resemble Alzheimer's, MS)

Phylum Fusobacteriota

• Spindle, football shape

• Obligate, facultative anaerobes

• Anoxic sediments and oral/intestinal habitats mammals, insects

• Opportunistic infections: Fusobacterium nucleatum, linked to colorectal cancer

• Oral biofilms: support architecture

• found in gingival crevices (oral bacteria)

• Periodontal lesions, pockets of gums (dental abscess), enter bloodstream

-Promote cancer growth, metastasis, resistance

Phylum Desulfobacteria

• Anaerobic sulfate or sulfur reducers, produce hydrogen sulfide

• Sulfur cycling in ecosystems

• Muds, sediments polluted lakes, streams, sewage

• Hydrogen sulfide in waterlogged soil may kill animals, plants, microbes

• Corrosion of iron in pipelines, heating systems

Phylum Bdellovibrionota

• Genus Bdellovibrio

• Aerobic, Gram-neg rods, polar flagella

• Alternate between non-replicating predatory phase and intracellular reproduction phase

• Known to be predatory, prey on other bacteria

Phylum Myxococcota

• Myxobacteria

• Aerobic soil bacterium

• Complex life cycle: forms fruiting bodies, spores called myxospores • Neutral soils, decaying plant material

• Preys on other bacteria, don't need for reproduction

• Secrete lytic enzymes, antibiotics to kill prey

• Myxospores: dormant, desiccation-resistant (survive 10+ years)

Phylum Campylobacterota - Campylobacter commensals

• Campylobacter (Genus)

• Motile

• GI, urogenital tract

• C. fetus Associated with spontaneous abortion (miscarriage)

• C. jejuni causes foodborne intestinal disease

-Most common bacterial foodborne illness in US

-From contaminated food, water

-Invades small intestine epithelium (inflammation) -Guillain-Barré Syndrome (Molecular mimicry): surface polysaccharides mimic nerve cell glycoproteins

Phylum Campylobacterota - Helicobacter commensals

Helicobacter (Genus)

• Multiple flagella

• Cause gastritis, peptic ulcers, and stomach cancer (acts as carcinogen)

• Person-to person transmission

• H. pylori, grow in acidic conditions