Lecture 7a- Microbial Diversity continued Flashcards
what does the bacterial phyla proteobacteria consist of?
chemolithotrophs
chemoorganotrophs
phototrophs
facultative organisms (can switch from one metabolic lifestyle to another)
what are the 6 classes of proteobacteria?
alphaproteobacteria
betaproteobacteria
gammaproteobacteria
deltaproteobacteria
epsilonproteobacteria
zetaproteobacteria
what does alphaproteobacteria consist of?
pathogens and non-pathogens
what is an example of a pathogenic alphaproteobacteria?
rickettsia rickettsii
what are characteristics of rickettsia rickettsii? what type of pathogen? how are they transmitted? what can it cause?
obligate intracellular pathogen
carried by insects and transmitted by insect bites
causes rocky mountain spotted fever
what is rickettsia rickettsii closest relative phylogenetically?
eukaryotic mitochondria
what is an example of a non pathogenic alphaproteobacteria?
rhizobium leguminosarum
what are characteristics of rhizobium leguminosarum?
forms root nodules on legume plants
symbiotic relationship
fixes nitrogen into a bioavailable form
plant provides nutrients and a home for the bacteria
what are characteristics of betaproteobacteria?
metabolically diverse
pathogens or non-pathogens
what is an example of a non-pathogenic betaproteobacteria? where does it live?
neisseria mucosa
lives on mucous membranes in human body
what is an example of a pathogenic betaproteobacteria? what does it cause
neisseria gonorrhoeae
causes gonorrhea
what are characteristics of gammaproteobacteria?
grow well in the lab and have become important research models
what is a common example of a gammaproteobacteria?
E. coli
what is E.coli? shape? oxygen requirements? type of flagella? ferments? where does it live? what is it an important indecator of?
gram negative, rod shaped
facultative aerobe
peritrichous flagella
ferments lactose to a mixture of acids and alcohols
lives in large intestine of warm blooded animals
serves as an important indicator of fecal contamination
what is a second example of a gammaproteobacteria?
pseudomonas aeruginosa
characteristics of pseudomonas aeruginosa? shape? motility? what is it naturally resistant to? what type of pathogen is it?
gram negative, rod shaped
motile through polar flagella
resistant to many antibiotics and disinfectants
opportunistic pathogen
what is an opportunistic pathogen?
causes infections in immunocompromised patients
ex. respiratory tract infections in cystic fibrosis patients
what is an example of deltaproteobacteria?
myxococcus xanthus
how do myxococcus xanthus move? how are they predatory? what happens when they are starved?
gliding motility, have adventurous motility and social, travel in waves
predatory because they release exoenzymes to lyse other bacteria for nutrients
when starved the cells migrate together to form fruiting bodies (differentiate into myxospores for dispersal)
what is a second example of deltaproteobacteria?
bdellovibrio bacteriovorus
what is the shape of bdellovibrio bacteriovorus? predator of what? gram + or -? how does it attack others?
curved
highly motile
predator of other proteobacteria and gram negative bacteria, penetrates cell wall and multiplies in the periplasm, this kills the cell
how is bdellovibrio bacteriovorus parasitic?
uses macromolecules obtained directly from the host
desulfovibrio is another example of deltaproteobacteria, what does it do?
reduces sulfate in oil, makes the oil go bad
obligately anaerobic
what is the epsilonproteobacteria? what is it famous for?
small class
famous for a few microaerophilic spirillum shaped pathogens
campylobacter jejuni is an example of epsilonproteobacteria, how is it transmitted? what is the most common cause? what does it cause?
frequently transmitted in undercooked chicken
most common cause of foodborne illness
causes bloody diarrhea and gastroenteritis
what does the bacterial phyla firmicutes consist of? gram + or -? what type of bacteria is it? what type of anaerobe?
gram positive cell wall (one of two phyla with this)
low guanosine cytosine gram positives
includes lactic acid bacteria
aerotolerant anaerobes that produce lactic acid as an end product of fermentation
what are two examples of lactic acid bacterial firmicutes? what do they do?
lactobacillus delbrueckii: yogurt production
streptococcus pyogenes: cause of strep throat, scarlet fever and flesh eating disease
what are two examples of non lactic acid bacterial firmicutes?
staphylococcus aureus
staphylococcus epidermidis
what are characteristics of staphylococcus aureus? what type of aerobe? what type of arrangement? where do they live? what do they cause?
facultative aerobe that forms characteristic grape like clusters
lives on skin
halotolerant (yellow on mannitol salt agar)
frequent cause of nosocomial infections
what does halotolerant mean?
can be isolated using media with high NaCl (ex. mannitol salt agar, produces acids (yellow))
where are staphylococcus epidermidis located?
skin
distinguished on mannitol salt agar as red, thus no acid production
some firmicutes are endospore forming, what two genus within the firmicutes are endospore forming?
bacillus
clostridium
what is the main difference between bacillus and clostridium genus?
bacillus are aerobic endospore formers
clostridium are strictly anaerobic endospore formers
are endospore forming firmicutes pathogenic or non- pathogenic? where do they live?
most are non- pathogenic saprophytic soil organisms
some are dangerous pathogens
bacillus subtilis is a species in the genus bacillus, what is so important about them?
used as a model organism for gram positive cell structure, cell division and differentiation into endospores
clostridium botulinum is a species in the genus clostridium, what kind of anaerobes are they? what do they produce?
strict anaerobe with a fermentative metabolism
produces a variety of exoenzymes to breakdown plant material
produces a deadly neurotoxin and when consumed causes botulism
clostridium botulinum can also grow in anaerobic canned foods, how can we prevent this?
proper canning procedures must either reach temp above 120 degrees celsius to destroy endospores or must include enough acid or sugar to prevent germination
there are several deeply branching phyla that consist of hyperthermophilic bacteria, what does this suggest?
that the last universal common ancestor (LUCA) may have been a hyperthermophile
what are the two famous hyperthermophilic bacterial species?
thermus aquaticus
deinococcus radiodurans
what microorganism class are thermus aquaticus?
thermophilic chemoorganoheterotroph
what is the importance of thermus aquaticus species?
allows DNA synthesis reactions in the lab to be carried out quickly at high temperatures and is an essential tool for polymerase chain reaction
what is unique about deinococcus radiodurans species?
form pairs or tetrads
extremely resistant to radiation, thus in response to radiation two cells will fuse together to facilitate repair
what gram stain do deinococcus radiodurans take on?
have a gram negative cell wall but stain gram positive because of thick peptidoglycan
