week 9: microbial diversity

microbial hyperthermophiles

gram-negative non-proteobacteria preferred temp

gram-negative non-proteobacteria preferred mode of energy

they are photosynthetic

examples of gram-negative non-proteobacteria hyperthermophiles

aquifex pyrohilus

genus thermotoga

aquifex pyrophilus

gram-negative non-proteobacteria hyperthermophile

grows best at 85 C

microaerophilic rod: a rod shaped bacteria that grows best in environments with low oxygen levels

genus thermotoga

gram-negative non-proteobacteria thermophile

grow at high temperatures

rod-shaped, wrapped with an outer envelope, toga-like structure

can grow on methanol and acetate

bacteria which shows as gram positive on stain but is really gram negative

phylum deinococcota

phylum deinococcota

gram-negative non-proteobacteria

one of the toughest bacteria in the world (resistant to desiccation and radiation)

can be spherical or rod shaped

stains as gram positive (purple color) but have a second membrane which results in them being gram negative truly

what is different about photosynthetic bacteria

they differ in pigments, shape, movement, general metabolic type, and electron donors

can do oxygenic or anoxygenic photosynthesis

oxygenic photosynthesis

usually done by gram-negative non-proteobacteria

carried out by cyanobacteria

there are 2 photosystems

light energy converted to chemical energy by producing oxygen as byproduct

H2O serves as an electron donor and its splitting results in producing oxygen

anoxygenic photosynthesis

gram-negative non-proteobacteria

purple sulfur bacteria, green bacteria, and aerobic anoxygenic phototrophic bacteria

liver in environments where light is available, but there's low O2

only 1 photosystem

electron donor is not water, does not produce oxygen therefore

3 bacteria that can do anoxygenic photosynthesis

1. purple sulfur bacteria

2. green bacteria

3. aerobic anoxygenic phototrophic bacteria

bacteriodota

gram-negative non-proteobacteria

make up to 30% of human feces

fusobacteria

gram-negative non-proteobacteria

bacteria with a spindle-shape, associated with infections and disease in humans

photolithotrophs

organisms that use light energy, inorganic electron donors, and CO2 as their carbon source for growth and metabolism

chemoheterotrophs

organisms that get their energy and carbon from organic compounds

chemoorganotrophs

obtain energy by oxidizing organic compounds like carbs, fats, and proteins

chlamydia

gram-negative non-proteobacteria

coccoid (spherical) shape and lack the ability to move (non-motile)

obligate intracellular parasite

obligate intracellular parasites

ex. chlamydia

must live and replicate inside a host cell, rely on the host for food and nutrients

have a small genome and are unable to metabolize carbs or synthesize energy molecules on their own

spirochaetota

gram-negative non-proteobacteria

chemoorganotrophs

have periplasmic flagella and move in a corkscrew-like fashion which helps them move over surfaces and dense environments

proteobacteria

most commonly encountered bacteria

very metabolically and morphologically diverse

5 main types of proteobacteria

1. alphaproteobacteria

2. betaproteobacteria

3. deltaproteobacteria

4. gammaproteobacteria

5. epsilonproteobacteria

alphaproteobacteria

oligotrophs (live in low nutrient environments)

metabolically diverse

largely defined by their relationships with nitrogen (therefore nitrogen related soil, and marine microbes)

ex. rhodobacteria uses light energy and has relationship with nitrogen

betaproteobacteria

largely oligotrophic

broad metabolic strategies

diverse environments (pathogens, groundwater)

ex.

- genus thiobacillus (sulfur oxidation -- chemolithotrophs)

- genus neisseria (causes gonorrhea)

- genus bordetela (B. Pertussis causes whooping/kennel cough)

deltaproteobacteria

1. mostly aerobic:

- bdellovibrio (predator)

- myxococcus (gliding)

2. anaerobic:

- desulfovibrio (sulfur reduction deep in the soil)

gammaproteobacteria

largest bacterial class

photoliths, enterics (intestinal tract), pathogens

6 major types:

1. enterobacteria (e. coli)

2. vibrionaceae

3. vibrio parahaemolyticus

4. vibrio cholerae

5. pseudomonadales (pseudomonas)

6. legionellales

enterobacteria

gammaproteobacteria

facultative anaerobes and CHEMOORGANOTROPHS

host can be found in aerobic or anaerobic environment so they must be able to adapt (and to nutrient availability)

found in soil environments where oxygen is limited

ex. e.coli

vibrionaceae

gammaproteobacteria

fluorescent and have quorum sensing

quorum sensing

ability of bacteria to sense the presence of other bacteria through secreted chemical signals

vibrio parahaemolyticus

gammaproteobacteria

gastroenteritis in humans from contaminated seafood

vibrio cholerae

gammaproteobacteria

causes cholera

pseudomonas (pseudomonadales)

gammaproteobacteria

motile and found commonly in hospital infections

diverse metabolisms and locations found

legionellales

gammaproteobacteria

intracellular pathogens which recognizes respiratory tract cells

epsilonproteobacteria

largely deal with the stomach and digestive tract

1. campylobacter:

- can cause reproductive disease and mimic host nerve cells

- polar flagella

2. helicobacter pylori:

- causes stomach ulcers by producing enzymes which burn stomach lining

- live in stomach, can remove with antibiotics

- peritrichous (all over cell surface) flagella

magnetotactic bacteria

not a type of proteobacteria, but a feature of them

move by the earth's magnetic field -- similar in concept to chemotaxis

helps orient the microbe in freshwater

identified in alpha, gamma, and delta proteobacteria classes

2 main types of gram-positive bacteria

1. firmicutes

2. cocci

2 types of firmicute gram-positive bacteria

1. genus bacillus

- endospore forming rods

- produce antibiotics

- have peritrichous flagella

- ex. B. subtilis, B. thuringiensis, B. anthracis, B. cereus

2. genus clostridiales

- form heat resistant endospores

- responsible for food shortage

- ex. C. botulinum, C. tetani, C. difficile

3 types of cocci gram positive bacteria

1. staphylococcus

- normally in skin and mucous membranes of warm-blooded animals

- can become opportunistic and cause diseases (S. aureus)

2. enterococcaceae

- typically a normal part of gut microflora (E. faecalis)

- can become opportunistic pathogen

3. streptococcaceae

- typically a normal part of the gut, respiratory, and mouth microflora

- disease causing: S. pyrogenes (strep throat), S. pneumoniae (pneumonia)

actinomycetes

typically anaerobic (or facultative), associated with hyphae

3 types

1. bifidobacterium

2. streptomycetales

3. mycobacteriaceae

actinomycetota bifidobacterium

human gut microflora (specifically infants)

actinomycetota streptomycetales

hyphae help produce antibiotics and mineralization

one of the largest bacterial genome

actinomycetota mycobacteriaceae

packed mycomembrane with mycolic acids

thick fat layer --> hydrophobic and impenetrable to antibiotics

ex. TB and leprosy

member of the domain bacteria whose genome shows it to be most closely related to archaea

thermotoga

cyanobacteria can be described as

some being photolithoautotrophs that can function as chemoheterotrophs in the dark

helicobacter pylori is responsible for

peptic ulcer disease

most of the oligotrophic proteobacteria are found in the

alphaproteobacteria class

species of the genus thiobacillus

oxidize inorganic sulfur compounds and produce ATP

produce acids that leach metals out of ore

are ubiquitous in soil, freshwater, and marine environments

clostridium causes what

botulism and tetanus

which of the following is extremely radiation resistant

deinococcus

match: non-proteo, gram negative bacteria

a bacterium that carries out photosynthesis without water as an electron donor

match: betaproteobacteria

a bacterium observed to form both endospores and biofilms

match: deltaproteobacteria

a bacteria able to reduce sulfate

match: alphaproteobacteria

an oligotrophic bacteria, found in a low nutrient environment

match: gram-positive bacteria

a bacterium observed to form both endospores and biofilms

match: gammaproteobacteria

a bacteria isolated from a human enteric system

match: epsilonproteobacteria

a bacteria isolated from a cow that has been found to be infertile