Chapter 11- Prokaryotes (EXAM 2) Flashcards
Classification in Carl Woese’s Three Domain System
Dr. King Phillip Came Over From Great Spain
Domain, Kingdom, Phylym, Class, Order, Family, Genus, Species
which of the three domains does not have kingdom?
bacteria and archae
Bergey’s Manual of Systematics of Archaea and Bacteria
Since 2015 Bergey’s Manual of Systematics of Archaea
and Bacteria has been published and updated (4x/yr)
online. The past five years, over 100 genera and six
hundred new species have been added to the manual
each year.
The new edition replaces and expands upon the second
edition of Bergey’s Manual of Systematic Bacteriology, a 5-volume set completed in 2012.
The (2nd) edition of Bergey’s Manual of Systematic
Bacteriology (2001-12) recognizes ____ phyla of Bacteria and ___ phyla of Archaea
24; 2
_____ are based on rRNA sequences. Considerable phenotypic diversity remains among the members of some _____.
phyla; phyla
Largest taxonomic group of bacteria containing
mostly chemoheterotrophic bacteria that are all
Gram-negative
Phylum Proteobacteria
Named after Proteus, a greek god of the sea, who
could assume many shapes (a great diversity of
forms is found in this phylum)
Phylum Proteobacteria
proteobacteria are said to have arisen from what common ancestor?
Proposed to have arisen from a common
photosynthetic ancestor, although few are now
photosynthetic.
what are the five classes of proteobacteria?
alpha, beta, gamma, delta, & epsilon proteobacteria
bacterium of the sea
pelagibacter (alphaproteobacteria)
A single marine species, ___________ ( derived from “ubiquitous”) has been isolated
One of most abundant microbes on Earth. Accounts for ___% of ocean bacteria and combined weight > all the fish.
One of the smallest (___ µm diameter), simplest (_______ genes) autonomously replicating cells
- shortest ________ spaces, no duplicate gene copies, viral genes, or junk DNA
Survives in a _____ nutrient environment (minimal genome and small size provide it a competitive advantage) gains energy by respiring _______ _______ or using a light driven proton pump. (don’t fix C- inorganic)
P. ubique; 25; 0.3; 1354; intergenic; low; organic carbon (Pelagibacter- alphaproteobacteria)
Why is a small cell size a competitive advantagous?
a higher surface area or volume allows the cell to move materials in and out more efficiently. A smaller cell has a higher surface are to volume ratio.
Caulobacter and Hyphomicrobium are part of which phylum?
alphaproteobacteria
found in low-nutrient aquatic environments (i.e. lakes),
produce prominent prostheca (cytoplasmic extrusion bounded by the cell wall [i.e. hypha or stalk.]) and have a dimorphic cycle
Caulobacter and Hyphomicrobium (alphaproteobacteria)
produce stalks for anchoring to surfaces and
increasing surface-to-volume ratios (both facilitate nutrient uptake. Stalk sizes increase when nutrient concentrations drop.
Caulobacter (alphaproteobacteria)
a type of alphaproteobacteria that replicates by binary fission
caulobacter (alphaproteobacteria)
a type of alphaproteobacteria that replicate by budding at
hyphal tips
Hyphomicrobium (alphaproteobacteria)
In the ______ life cycle, morphogenic events are an intrinsic part of the _________ cell cycle/
Caulobacter; Caulobacter
is motile for part of its life, then the flagella is lost,
and a stalk is formed
caulobacter
In Caulobacter, what happens after surface attachement?
Following surface attachment, reproduction can
occur, resulting in one stalked cell and one flagellated swarmer cell.
Describe the Caulobacter life cycle
- flagellated swarmer cell that can’t replicate
- the flagellum is lost
- stalk begins to form when the organism attached to a surface
- stalk elongates
- division begins, flagellul forms on new cell
- new cell with flagellum swims off as swarmer cell, and the stalked cell initiates a new round of replication
What does the life cycle of hyphomicrobium look like?
- the hypha starts forms
- new nucleoid moves into the hypha
- a young bud forms
- the bud develops
- swarmer cell with subpolar to lateral flagellum made (1-3)
- Now the hypha lengthens as low nutrient conditions increase and it produces another bud
A ___________ cell adheres to surfaces via a polar holdfast opposite the hypha
hyphomicrobium
forms hyphae-like, cytoplasm-filled prostheca with end bud
hyphomicrobium
Of the alphaproteobacteria, which are nitrogen-fixing?
Rhizobium
Azospirillum
agrobacterium
acetobacter and gluconobacter
- enter the roots of leguminous plants (beans, peas, clover) and form nodules
• Fix N2 in a symbiotic relationship with the plant
• cannot independently fix nitrogen
Rhizobium (+ 4 other genera,
(i.e. Bradyrhizobium)
• commonly called rhizobia
(Alphaproteobacteria)
- A free-living, plant root surface colonizing soil bacterium commonly found on tropical grasses and sugar cane
- use nutrients excreted by plants and fixes nitrogen in return
Azospirillum (alphaproteobacteria)
prefix Azo, means ________ ______. Thus, nitrogen
became associated with term “Azo”, which is frequently
used in the names of nitrogen-fixing genera
without life
plant pathogens
invade plant cells but do not induce nodules or fix nitrogen
agrobacterium (alphaproteobacteria)
induces crown gall
disease in plants through the
insertion of the Ti plasmid into
the plants genome.
A. tumefaciens (Agrobacterium, alphaproteobacteria)
• called acetic acid bacteria
• Industrially important aerobic organisms that
oxidize ethanol to acetic acid (vinegar)
• Thus, found in environments where ethanol is
formed from the fermentation of sugars to ethanol
Acetobacter and Gluconobacter (alphaproteobacteria)
prefer ethanol as carbon
source, while Gluconobacter prefers sugar
acetobacter
Of the alphaproteobacteria, which are nitrifying bacteria?
Nitrobacter and Nitrosomonas
Chemoautotrophic
oxidize nitrogen for energy and fix CO2
which bacteria: NH4+ —> NO2-
Nitrosomonas
which bacteria: NO2- ——> NO3-
Nitrobacter
What is nitrification?
the process in which bacteria in the soil use oxygen to change compounds of nitrogen in dead plant material into nitrates which plants can then absorb as food
Why is nitrate production important for the environment?
Nitrate production is critical for the environment and
agriculture because they are more easily absorbed from
the soil by plants than either nitrite or ammonium ions
a member of the Beta proteobacteria class
Nitrosomonas
Of the alphaproteobacteria’s, which is a facultative intracellular parasite?
Bartonella
Brucella
bacillus that inhabits the interior of some cat red blood cells (cats are not sick) primary mode of transmission to humans is infected flea feces by a cat scratch, bite etc.: causes cat-scratch disease/fever (more common than lyme disease in the U.S.).
B. henselae
In Bartonella several members are _______ ________
human pathogens
What is a facultative intracellular parasite?
Facultative intracellular parasites are capable of living and reproducing either inside or outside cells.
What disease does Brucella cause?
causes Brucellosis
disease of ruminants that also affects humans
Brucellosis
how is brucellosis spread?
spreads to humans by ingestion of undercooked
meat or unpasteurized dairy products - species have different affinities for host mammals.
How is Brucella able to survive phagocytosis?
After phagocytosis by macrophages, able to
survive in phagosomes by blocking lysosomal
fusion.
What is an obligate intracellular parasite?
cannot reproduce outside their host cell, meaning that the parasite’s reproduction is entirely reliant on intracellular resources.
Of the alphaproteobacteria’s, which are obligate intracellular parasite?
Rickettsia, Ehrlichia
highly pleomorphic bacteria (rods or coccobacilli)
- preferentially infect endothelial cells lining
the small blood vessels by inducing phagocytosis. They escape the phagosome
and enter the cytosol where they replicate
Rickettsia
transmitted to humans by insect and tick bites
- cause a number of diseases known as the spotted fever group
Rickettsia
lice—> Epidemic typhus
R. prowazekii
rat fleas —> Endemic murine typhus
R. typhi
ticks —–> Rocky Mountain spotted fever
R. rickettsii
rickettsia-like bacteria - transmitted by ticks to humans
Ehrlichia
Disease caused by Ehrlichia
ehrlichiosis
How is Ehrlichia able to survive in phagosomes after phagocytosis by macrophages?
After phagocytosis by macrophages, able to survive in
phagosomes by blocking lysosomal fusion.
Of the alphaproteobacteria’s which are endosymbionts?
Wolbachia
Although not human pathogens, they may be the most common infectious bacterial genus on earth (infecting over a million species)
Wolbachia
Wolbachia lives as an endosymbiont in the cells of what?
insects and other invertebrates
What percentage of insects are infected with Wolbachia?
20-75%
How is Wolbachia’s relationship with its hosts complicated?
its interactions with its hosts
are often complex, and in some cases have evolved to symbiotic rather than parasitic
Why is Wolbachia interesting?
Much interest due to its ubiquitous distribution,
many different evolutionary interactions, and potential
for pest control
wolbachia is essential in which organism?
nematodes
pea aphids gain resistance to parasitic ________
- harmless to aphids but kill ______ larvae
wasps
some pathogenic “_________” Wolbachia strains cause host cells to lyse or “_____”, eventually kills insect
popcorn; pop
Since __________ are only transferred from mother to
offspring, some species alter host reproductive
capabilities in different ways to increase its own
transmission. What are the two mechanisms by which it accomplishes this?
Wolbachia;
1) males killed during larval development which increases the female to male ratio
2) infected males develop as females or infertile pseudo-females.
Where would Paelagibacter be placed in the alphaproteobacteria dichotomus key?
Echo slide 26
Chemoautotrophs and chemoheterotrophs that often use nutrients that diffuse away from the anaerobic decomposition of organic material (hydrogen gas, ammonia, methane). All are
aerobic.
Betaproteobacteria
relatively large cell bodies that twist like a spiral
- motile due to bipolar tufts of flagella
- habitat is mainly fresh water
Genera Spirillum (Betaproteobacteria)
How long are spirillum?
60 microns
filamentous sheathed bacteria found in slow moving fresh water streams and sewage
- the tube-like sheath protects the cells from drying and aids in surface attachment
- Individual mature cells swarm out of the protective tube to
colonize new sites
Genera Sphaerotilus (Betaproteobacteria)
Obligate aerobe betaproteobacteria
thiobacilus
Oxidize reduced sulfur for energy and fix CO2. Convert hydrogen sulfide (H2S) or elemental sulfur into sulfates (SO4^2-). Important in the sulfur cycle
thiobacilus
Which of the betaproteobacteria genera include pathogenic species?
burkholderia (B. cepacia, and b. pseudomallei), Bordetella, Neisseria
reclassified from Pseudomonas
- rod-shaped bacteria found in soil
- single flagella or tuft of flagella
Burkholderia (Betaproteobacteria)
can degrade >100 different organic molecules
- problematic contaminant of hospital equipment and drugs
(can even grow in disinfectant solutions)
- opportunistic pathogen that infects the respiratory tract of
cystic fibrosis patients (metabolizes respiratory secretions)
B. cepacia: (“cepia” is latin for onion) (Burkholderia)- Betaproteobacteria
the cause of a severe disease (melioidosis) that is endemic in SE Asia and N. Australia.
B. pseudomallei (Burkholderia) (Betaproteobacteria)
nonmotile rods/coccobacilli
* adhere to cilia of bronchial epithelium
* causitive agent of pertussis
or whooping cough
• Bordetella:
- B. pertussis
Betaproteobacteria
- diplococci
- Use fimbriae to attach to the mucous
membranes of urethra in mammals
Neisseria; Betaproteobacteria
meningococcal meningitis
*N. meningitidis (Neisseria- Betaproteobacteria)
gonorrhoeae
N. gonorrhoeae (Neisseria- Betaproteobacteria)
The largest subgroup of Proteobacteria. Encompass a wide variety physiological types that live in diverse environments: soil, water, mammalian hosts
gammaproteobacteria
Gammaproteobacteria orders
- Pseudomonas
- Legionellales
- Vibrionales
- Enterobacteriales
- Pasteurellales
Genera in Order Pseudomonadales
Gammaproteobacteria:
Generas in Order Pseudomonadales-
- Pseudomonas
- Acinetobacter
- Moraxella
- Azotobacter and Azomonas
Genera in Order Legionellales
Gammaproteobacteria:
Generas in Order Legionellales- contains 2 aerobic families
- Legionella
- Coxiella
Genera in Order Vibrionales
Gammaproteobacteria:
Generas in Order Vibrio
Genera and Family in Order Enterobacteriales
Gammaproteobacteria:
Generas in Order Enterobacteriales-
- Escherichia
- Salmonella
- Shigella
- Klebsiella
- Serratia
- Proteus
- Yersinia
- Enterobacter
Family: Enterobacteriaceae
Genera in Order Pasteurellales
Gammaproteobacteria:
Generas in Order Pasteurellales-
- Pasteurella
- Haemophilus
- Aerobic rods
- Common in soil
- Polar flagella (single or tufts)
- Opportunistic pathogens
- infect urinary tract, burns and wounds in a weakened host
- Many can grow at refrigerator temperatures (food spoilage)
- Have a large genetic capacity (≈yeast) for expression of a
large amount of enzymes that catabolize a wide variety of substrates (beneficial for decomposing uncommon chemicals in the soil but problematic in hospitals) - generally antibiotic resistant: large genome codes for several efficient efflux pumps
- many species excrete water soluble pigments
- some species moved to Burkholderia based on rRNA studies
Pseudomonas
Name means “nonmotile rod”, but morphology
species can be pleomorphic (rods to cocci)
- aerobic and found naturally in soil and water
Acinetobacter
- opportunistic pathogen found in hospital settings
- primarily respiratory pathogen, but also infects skin, soft tissues and wounds
- concerns:
- rapidly becomes resistant to antibiotics such that some
strains are resistant to most available antibiotics. - difficult to eliminate once established in a hospital
because it survives on artificial surfaces and resists
desiccation
A. baumanii
Acinetobacter
Pseudomondales
Gammaproteobacteria
aerobic coccobacilli of gammaproteobacteria
Moraxella
One of several bacteria that can cause conjunctivitis (pink eye): inflammation of the outermost layer of the eye and the inner surface of the eyelids
M. lacunata
Moraxella
Pseudomondales
Gammaproteobacteria
large ovoid heavily capsulated bacteria
- free living soil bacteria that fix nitrogen (obtain energy from organic sources in the soil).
Azotobacter and Azomonas (monas= unicellular organism)
Pseudomondales
Gammaproteobacteria
Found in streams, warm-water pipes, HVAC cooling towers
- Facultative intracellular parasites found in the environment either free-living or within amoeba. Found in pulmonary macrophages in humans.
Legionella
The amobea shelter ___________, protecting them from chemical disinfectants, drying and heat
- Humans are accidental hosts by inhalation of water droplets
legionella
(first identified during
1976 outbreak) (29 of 182 died)
L. pneumophilia: Legionnaires Disease (pneumonia)
Legionella
Legionellales
Gammaproteobacteria
Originally grouped with rickettsia (obligate intracellular
parasites) but NOT transmitted among humans by insect or
tick bites
- Wild & domestic animals are reservoirs for the rod-shaped
organism. Transmitted to humans via inhalation of animalderived
dusts and aerosols (urine, feces etc.) or contaminated milk
- Causes flu-like pneumonia called Q fever (named Q for
query when causitive agent was
unknown)
- highly resistant to environmental
stresses such as heat and drying;
perhaps due to an endospore-like
body in the cell.
C. burnetti
Coxiella
Legionellales
Gammaproteobacteria
facultatively anaerobic curved rods that are mostly
found in aquatic environments
Gammaproteobacteria
Order Vibrionales
Vibrio
- causes cholera, characterized by profuse,
watery diarrhea
vibrio cholerae
Gammaproteobacteria
Order Vibrionales
Vibrio
- gastroenteritis from
eating raw or
undercooked shellfish
V. parahaemolyticus
Gammaproteobacteria
Order Vibrionales
Vibrio
inhabit intestinal tracts of
humans and mammals
enterics
- enterics – facultatively anaerobic rods – Most ferment glucose and other sugars – if motile, have peritrichous flagella – Fimbriae to aid with adhesion – Sex pili for exchange of genetic material— frequently confer antibiotic resistance
Gammaproteobacteria
• Order Enterobacteriales
(only one family: Enterobacteriaceae)
- common inhabitant of human intestinal tract
but not most abundant (0.1% of gut flora) - a great deal is known about its biochemistry and
genetics - not usually pathogenic but can cause urinary
infections and certain strains produce
enterotoxins that cause traveler’s diarrhea or
foodborne disease - presence in food or water indicates fecal
contamination
Gammaproteobacteria
Order Enterobacteriales
• Escherichia
- E. coli
all members are potentially pathogenic
- common inhabitants of many animals, especially
poultry and cattle
- can contaminate food under unsanitary conditions
Gammaproteobacteria
Order Enterobacteriales
• Salmonella
What two species are recognized in the genus Salmonella?
- Salmonella enterica
* Salmonella bongori (“cold blooded” animal resident)
- Salmonella enterica
- Salmonella bongori (“cold blooded” animal resident)
• These 2 strains are subclassified into ______ serovars
2400
Most of these serovars (______) belong to
________ ______, and cause more than 99% of
the diseases in humans
1531; Salmonella enterica
“Salmonella enterica serovar Typhimirium” is
generally written as what?
a species, S. typhimirium
causes typhoid fever (Salmonellosis is a less
severe gastrointestinal disease caused by other Salmonella)
S. typhoid
•Defined by the antigenic expression, O and H, that relate to variant
lipopolysaccharides and flagella, respectively
Kauffmann-White Salmonella Serovar Reporting Scheme
________ formulas are used for unnamed Salmonella serotypes
antigenic
Salmonella (_______); ________ (O antigen) : (____antigen) : (_____ antigen)
species; serotype
Salmonella enterica serotype Typhimurium = Salmonella enterica serotype _____________
1, 4, 5, 12 : i : 1, 2 (slide 46)
What is the disease caused by Shigella, and how many species cause it?
all 4 species are responsible for shigellosis
although ___________ causes deadly epidemics,
not prevalent in U.S
- only found in humans (No other natural reservoirs
have been proven)
S. dysenteria
Gammaproteobacteria
Order Enterobacteriales
• Shigella
common in soil and water
- many isolates can fix nitrogen
- ___________ can cause a serious form of
pneumonia
K. pneumoniae
Klebsiella
Gammaproteobacteria
Order Enterobacteriales
__________ is the primary pathogenic species
and is distinguished by production of a red pigment
* causes hospital many urinary and respiratory
infections. Likely because it is found in hospital
solutions in hospitals that
should be sterile (i.e. cathetors,
saline solutions)
S. marcescens
Gammaproteobacteria
Order Enterobacteriales
Serratia
Genus can become pathogenic if it enters the urinary tract or a wound.
- Unique multicellular behavior: a ________ colony on agar exhibits a distinctive series of
concentric rings due to swarming growth.
1) On the edge of the colony, “swarmer” cells with many flagella move outward
2) they then revert to normal, less motile cells, with few flagella, “swimming” state
3) new generations of swarmer cells periodically develop, and the process is repeated
Gammaproteobacteria
Order Enterobacteriales
• Proteus
What occurs to the cell to permit swarming?
20-40 fold increase in both cell length and flagella number
________ causes plague (black death of medieval
Europe)
(In a 5 yr. span in 1300’s, 35% of Europe’s
population was killed)
* Urban rats in some parts of the world and
squirrels and prairie dogs in Southwest U.S.
carry the bacteria.
* fleas bites generally transmit bacteria from
animals to humans
- inhalation of respiratory droplets from infected
animals or people can also lead to infection
Y. pestis
Gammaproteobacteria
Order Enterobacteriales
• Yersinia
What are the two known species of Enterobacter that cause disease?
Two species are known to cause disease, E. cloacae (klōā’kē)
and E. aerogenes (ā-rä’jen-ēz).
Their presence in the intestinal tracts of animals results in
their wide distribution in soil, water, and sewage.
* both can both cause urinary and hospital acquired
infections
Gammaproteobacteria
Order Enterobacteriales
Enterobacter
E. cloacae
E. aerogenes
pathogens of domestic animals
- Best know species is ___________, which can be
transmitted to humans via dog and cat bites. It presents as an
infection that complicates the animal bite or injury.
* an especially virulent strain
is present in Komodo dragon
saliva and is introduced into
its more mobile prey by a
bite (kills in several days)
P. multocida
Gammaproteobacteria
Order Pasteurellales
• Pasteurella
- pathogens that inhabit the mucus membranes of the upper respiratory tract, mouth, vagina and intestinal tract
- named for their blood requirement in culture media
Haemophilus
Gammaproteobacteria
Order Pasteurellales
hemo
blood
philus
liking
clinical labs use their requirements for ___ (heme from hemoglobin) and ___ (NAD+ or NADP+) factors to I.D
X; V
* mistakenly considered to be the cause of influenza until 1933 * Causative agent of meningitis, earaches, bronchitis, pneumonia and septic arthritis
H. influenzae
Haemophilus
Gammaproteobacteria
Order Pasteurellales
causes the sexually transmitted
disease chancroid
H. ducreyi
Haemophilus
Gammaproteobacteria
Order Pasteurellales
When is there H. influenza growth on a culture media plate?
only around disc
impregnated with both X and V factors
type of deltaproteobacteria that is anaerobic?
desulfovirbrio
types of deltaproteobacteria that is aerobic?
predator and gliding
Predator: Bdellovibrio
Gliding: Mycococcus
bdella
leech
attaches tightly to other gram-negative bacteria, penetrates the outer layer and enters the periplasm - It breaks down the host cell molecules, which it uses to elongate and form a filament. - filament fragments into several individual flagellated cells that are released by cell lysis
Deltaproteobacteria
• Genus Bdellovibrio
Would B. bacteriovirus attack S. aureus?
slide 57
Sulfur reducing bacteria that play a key role in the sulfur cycle
• Use oxidized S (i.e. S0, SO4
2- ) instead of O2 as final electron
acceptor and produce reduced H2S
Deltaproteobacteria
Members of the order Desulfovibrionales
* obligate anaerobes found in sediments and intestinal tracts of humans and animals * use organic compounds such as lactate, ethanol or fatty acids as electron donors * black color of many sediments/sludge is due to H2S reacting with iron to form insoluble FeS
Desulfovibrio (best studied genus)
Deltaproteobacteria
Members of the order Desulfovibrionales
Illustrate the most complex life cycle of bacteria (part predatory
upon other bacteria)
Deltaproteobacteria
Order Myxococcales
myxo
nasal mucus
- vegetative cells move by gliding motility and leave a slime trail
- obtain nutrition from bacteria they encounter and
enzymatically lyse. - cooperative predation is
accomplished by secretion of
antibiotics and lytic compounds
that immobilize and degrade
prey organisms, thereby creating
a public pool of nutrients
Myxococcus
Deltaproteobacteria
Order Myxococcales
Describe the life cycle of Order Myxococcales
- Myxospores: Myxospores are resistant resting cells released from sporangioles upon favorable conditions
- Germination: myxospores germinate and form gram-negative vegetabtive cells, which divide to reproduce
- Vegetative growth cycle: vegetative myxobacteria are motile by gliding, forming visible slime trails
- Aggregation: under low nutrient conditions, the vegetative cells swarm to central locations by quorum sensisng, forming and aggregation
- Mounding: aggregations of cells heap up into a mound, an early fruiting body
- Mounds of myxobacteria differentiate into a mature fruting body, which produces myxospores packed within sporangioles
How many cells are in a myxobacteria fruiting body?
About 100,000 cells
\_\_\_\_\_\_\_\_\_\_ are formed within a cell, whereas \_\_\_\_\_\_\_\_\_\_ are formed when the entire cell differentiates into a spore
endospores; myoxospores
Slender rods that are helical or curved. Are microaerophilic and motile by means of flagella
Epsilonproteobacteria
What are the two genera of Epsilonproteobacteria?
Campylobacter
Helicobacter
_______________
– Single polar flagella
– ________ is a leading cause of foodborne gastroenteritis
– ________ causes spontaneous abortion in domestic
animals
Campylobacter
C. jejuni
C. fetus
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Multiple flagella \_\_\_\_\_\_\_\_ is the most common cause of peptic ulcers (prior to 1982 not thought to have a microbial cause) and also a cause of Stomach cancer
Helicobacter;
H. pylori
Oxygenic Photosynthetic Bacteria (_________)
chlorophyll a
– Named for characteristic blue-green pigmentation and also called
“blue-green algae”
– Are bacteria— NOT eukaryotic algae, although they resemble them, use
chlorophyll and share same ecological niches
– believed to have generated most of the Earths atmospheric O2 millions of
years ago (0.1%è10% when plants arrived)
Photosynthetic, Gram Negative Bacteria
• Phylum Cyanobacteria
Oxygenic Photosynthetic Bacteria (chlorophyll a)
What are the different types of morphology found in cyanobacteria?
Unicellular: divide by binary fission
• Colonial: multiple fission (parent divides multiple times by mitosis,
producing several nucleoids. Cytoplasm then separates creating
multiple daughter cells at once)
• Filamentous: fragmentation
Many filamentous cyanobacteria fix nitrogen in specialized cells called
_________
heterocysts
Unicellular nonfilamentous
Cyanobacterium (binary fission) held together by
__________________
mucopolysacchariades
• Are generally anaerobic
• grow at great aquatic depths and use bacteriochlorophyll (utilizes a portion of the light spectrum not intercepted by organisms
at higher levels).
• morphologically diverse (spiral, rods, cocci and budding forms)
Anoxygenic Photosynthetic Bacteria
Nonproteobacteria, Gram Negative Bacteria
green nonsulfur bacteria
Phylum Chloroflexi
green sulfur bacteria
Phylum Chlorobi
purple nonsulfur bacteria
Phylum Proteobacteria (gamma)
purple sulfur bacteria
– Phylum Proteobacteria (alpha)
purple bacteria have various
_________, which give them
colors ranging between purple,
red, brown, and orange
carotenoids
most green sulfur bacteria are green
but some have a ______ tint.
brown
Oxygenic photosynthesis
Cyanobacteria:
2H2O + CO2
light———>(CH2O) + H2O + O2
Anoxygenic photosynthesis
Purple/ Green Sulfur Bacteria:
2H2S + CO2
light———> (CH2O) + H2O + 2S0
Photoautotrophs that use organic compounds (acids and carbohydrates)
for the photosynthetic reduction of CO2
Purple/Green NON-Sulfur Bacteria
How are gram positive bacteria classified?
Their G/C content in their genetic material
Which Phylum of gram positive bacteria has a low GC content?
Phylum Firmicutes
Which Phylum of gram positive bacteria has a high GC content?
Phylum Actinobacteria
Draw the dichotomous key for Firmicutes
slide 68
- common in soil
- endospore forming
- obligate anaerobes
- rod shaped, often distended due to presence of endospores
Clostridium
Firmicutes
Order: Clostridiales
special resistant, dormant structure formed within a cell that protects a bacterium from adverse environmental conditions. Capable of withstanding extreme heat, lack of water, exposure to toxic chemicals
endospore
GI tract infections
Clostridium difficile
Clostridium
Firmicutes
Order: Clostridiales
food poisoning
C. botulinum
Clostridium
Firmicutes
Order: Clostridiales
tetanus
C. tetani
Clostridium
Firmicutes
Order: Clostridiales
foodborne diarrhea
C. perfringens
Clostridium
Firmicutes
Order: Clostridiales
lives symbiotically in the gut of a Red Sea surgeon fish (1985)
- Considered too large to be a bacterium (visible by naked eye),
it seems to break the known rules of size/diffusion limitation
* Its cell wall contains many folds that increase surface area
and the organism is literally bathed in undigested food
* Doesn’t rely on diffusion to distribute nutrients because it
synthesizes macromolecules where needed.
Epulopiscium
Firmicutes
Order: Clostridiales
Why was Epulopiscium initially classified as a protozoan, and then reclassified as bacterial?
* lack of membrane enclosed nucleus * structures resembling protozoan cilia were actually bacterial flagella * analysis of rRNA
How much larger in volume is Epulopiscium than E.coli?
E. coli (1 µm x 2 µm) Epulopiscium (80µm x 600 µm) 1 million times larger volume
__________ daughter cells grow within the mother cell
until they fill the cell and burst the cell wall
Epulopiscium
How many daughter cells are released from the mother cell in Epulopiscium?
1 to 7
How much larger is the Epulopiscium genome than the human cell?
25X
How many copies of its genome are found in Epulopiscium?
contains tens of thousands of copies of its genome
which may allow it to overcome diffusion constraints.
- Endospore–forming rods
- obligate aerobes or facultative anaerobes
- Common in soil and often forms chains in culture
- several species produce antibiotics
- only a few pathogenic to humans
Bacillus
Firmicutes
Order: Bacillales
- disease of cattle, sheep and horses that can be transmitted to humans (linked with bioterrorism)
Bacillus anthracis:
Bacillus
Firmicutes
Order: Bacillales
- agriculturally important insect pathogen used as a pesticide
Bacillus thuringiensis:
Bacillus
Firmicutes
Order: Bacillales
- associated with food poisoning, typically through infection of starchy foods (i.e. rice)
Bacillus cereus:
Bacillus
Firmicutes
Order: Bacillales
What differentiates Bacillus anthracis, Bacillus thuringiensis, Bacillus cereus from each other?
These 3 species are considered to be variants of the same species differing only by virulence genes carried on plasmids easily transferred one to another
Typically arrange themselves in grape-like clusters
§ Considered part of our normal flora
§ Grow well in high osmotic pressure, low moisture conditions (nasal
passages and on skin)
§ Facultative anaerobic, cocci bacteria
Staphylococcus
§ Golden in color (may protect from antimicrobial effects of sunlight) § Produce many exotoxins that aid in pathogenicity (allow invasion or damage tissues) § Commonly infect surgical wounds § Develops drug resistance quickly § Infections differ by anatomic region: - Vaginal tract: toxic shock syndrome - GI tract: food poisoning - Respiratory tract: sinus infections
Staphylococcus aureus
Staphylococcus
Firmicutes
Order: Bacillales
What are the genus found in Bacillales?
Bacillus and Staphylococcus
What are the Orders found in Phylum Firmicutes
Clostridiales
Bacillales
Lactobacillales
Mycoplasmatales
What are the genus found in Lactobacillales?
Lactobacillus
Streptococcus
Enterococcus
Listeria (named after Joseph Lister)
What are the genus found in Mycoplasmatales?
Mycoplasmas
- Generally aerotolerant anaerobes
- In humans, can be found in oral cavity, vaginal and GI tracts
- Commercially important in pickle, yogurt, sauerkraut and buttermilk
production
Most lack an electron-transport chain
Lactobacillus
Order: Lactobacillales
Firmicutes
Why is it bad that lactobacillus doesn’t have an ETC?
inefficient metabolism; can’t utilize oxygen as e-acceptor
grow poorly compared to oxygen utilizing bacteria
Why is it beneficial that lactobacillus doesn’t have an ETC?
they generate lactic acid from simple carbohydrates and the low pH inhibits the growth of competing organisms.
Spherical bacteria that typically grow in chains – responsible for more illnesses and greater number of diseases than any other genus – Express and secrete a number of substances that aid in its survival and pathogenicity • Proteins to kill phagocytic cells • Enzymes that help spread infection - digesting host connective tissues which may also cause tissue destruction - destroying fibrin, a component of blood clots
Streptococcus
Order: Lactobacillales
Firmicutes
classified based upon their colony
appearance on blood agar medium
Streptococci
express hemolysin that lyses red blood
cells, leaving a clear zone around the colony
Beta-hemolytic species
species partially degrade red blood cells (due to
hydrogen peroxide production only in the presence of oxygen) and their
colonies are surrounded by a distinctive greening
Alpha-hemolytic species
species do not affect red blood cells
Gamma (non-hemolytic) species
(Beta-hemolytic Group A Strep): causative agent of Scarlet
and Rheumatic Fever
S. pyogenes
Beta-hemolytic Group B Strep: neonatal sepsis
S. agalactiae
cause of pneumococcal pneumonia
S. pneumoniae (alpha hemolytic)
primary cause of dental caries
S. mutans (alpha hemolytic)
a non-Linnaenan term for a large group of normal
microbiotia streptococcal bacteria that are either α-hemolytic or nonhemolytic
viridans
Part of our normal intestinal flora that occasionally cause urinary tract infections and sepsis – Adapted to nutrient rich but low oxygen body regions - GI tract - oral cavity - vagina – Major cause of hospital-acquired infections because they persist on inanimate objects for long periods of time and have high resistance to most antibiotics
Enterococcus
Order: Lactobacillales
Firmicutes
________ and _______, are responsible for most
surgical wound and urinary tract infections
E. faecalis and E. faecium
Enterococcus
Order: Lactobacillales
Firmicutes
usually the causative agent of
listerosis, a serious infection caused by eating food
contaminated with the bacteria.
§ one of the most virulent foodborne pathogens (20-30% of
clinical infections result in death)
- a 2011 Listerosis outbreak from contaminated
cantaloupe sickened 147 people and killed 33
§ Can survive within phagocytic cells and infection of
pregnant women poses risk to developing fetus
§ Capable of growth at refrigeration temperatures
L. monocytogenes
Listeria
Order: Lactobacillales
Firmicutes
Lack a cell wall; pleomorphic as a result
named because they
can produce filaments that resemble those associated with fungi
Are very small (0.1 - 0.24 µm) and originally classified as viruses
• May be the smallest, self-replicating, free-living life form
• Analysis of their DNA suggests they were once closely related to other families but lost genes over time
• Mycoplasmas
Order: Mycoplasmatales
Firmicutes
is the most significant species of “mykes”, causing a mild
pneumonia
M. pneumoniae
• Mycoplasmas
Order: Mycoplasmatales
Firmicutes
mykes
fungus
plasma
formed
High G + C and Gram-positive
Actinobacteria
Genera found in the Phylum Actinobacteria
Nocardia Frankia Streptomyces Actinomyces Mycobacterium Corynebacterium Propionibacterium
How are genera classified in the Dichotomous key for Actinobacteria?
genera appear to
radiate due to the number of branching filaments associated with
them
Draw the dichotomous key for Actinobacteria
slide 82
Some are highly pleomorphic in morphology and others
grow only as extended, often branching filaments
actinobacteria
actinobacteria have high _____ content
GC
The genera ___________ in actinobacteria is pleomorphic
Corynebacterium
Filamentous genera resemble fungi but are __________. Some, like fungi, carry external spores for reproduction and are common inhabitants of soil.
prokaryotes
Why is the filamentous design of some actinobacteria advantageous?
- organism can bridge a water-free gap to a new
nutritional site - increased surface area for greater nutrient
absorption
The genus __________ is one of the most common soil isolates. Strict aerobes. Produce a gaseous compound, _________, that gives soil its musty odor
• Valuable because they produce most of our commercial antibiotics
Streptomyces; geosmin
Reproductive asexual spores (____________) form at the end of the
coiled aerial filaments that can germinate into a new colony if released
into proper conditions
conidiospores
not Gram positive
Aerobic, non-spore forming rods
_______= Fungus-like; so named because they occasionally
exhibit filamentous growth
- Cell wall is similar to gram negative bacteria but the
outermost lipopolysaccharide layer of their cell wall is
replaced by _______ acids, giving them a waxy, water resistant
layer. This results in:
* Acid-fast staining
* blocked entry of antimicrobial compounds
* resistance to environmental stressors like drying
* reduced nutrient uptake and growth rate
MYCOBACTERIUM
myco; mycolic;
Important members of mycobacterium
M. tuberculosis and M. leprae,
causative agents of tuberculosis and leprosy, respectively
Facultative anaerobes, branched filaments that replicate by fragmentation • Common in soil and animal microbiota, present in the mouth and throat of humans • Causative agents of \_\_\_\_\_\_\_\_\_\_\_\_\_, a tissue destroying disease affecting the head, neck or lungs
actinomycosis; Genus Actinomyces: actinobacteria
• Morphologically similar to ____________ and also replicate by
fragmentation
• Aerobic, acid-fast bacteria (not gram positive)
• Common in soil
actinomyces; genus nocardia; actinobacteria
can causes a chronic pulmonary
infection and is also the cause of mycetoma, a localized,
infection affecting feet and hands
nocardia asteroides
genus nocardia
actinobacteria
coryne
club-shaped
Genus __________
pleomorphic, morphology often changes with age
• ___________ is the causative agents of diphteria
Genus Corynebacterium:
C. diphtheriae i
Actinobacteria
Genus ______________
named for ability to form ________ acid
• some species important in the formation of Swiss cheese
• ________ are commonly found on human skin
and implicated as the primary bacterial cause
of acne
Genus Propionibacterium; propanoic acid; P. acnes
Actinobacteria
Genus _____________: causes nitrogen-fixing nodules to form on
alder tree roots
Frankia
Actinobacteria
Phylum \_\_\_\_\_\_\_\_\_\_\_\_\_: • Gram negative, budding bacteria • Blur the definition of bacteria – Bacterial rRNA gene sequence - Some have organelles resembling those of eukaryotic cells
Planctomycetes
Genus _____________:
– Aquatic bacteria that produce stalks like ___________
Planctomyces; caulobacter
Phylum Planctomycetes
- May be a model for the origin of the
eukaryotic nucleus - Double internal membrane around
DNA, like a nuclear membrane
Gemmata obscuriglobus
genus planctomyces
phylum planctomycetes
What was an important recent research finding about Chylmadia?
Historically it was believed that all Chlamydiae species had
a peptidoglycan-free cell wall, but recent work demonstrated a
detectable presence of peptidoglycan
(2014 Nature paper detects peptidoglycan in Chylmadia!)
Phylum ____________:
Grow intracellularly (obligate) within a eukaryotic host (like
Rickettsiae)
• Gram negative cocci.
• Direct Transmission: interpersonal contact or aerosols (not by
ticks etc)
• Lab cultivation is difficult; must cultivate in lab animals, cell
culture or the yolk sac of embryonated chicken eggs
Phylum Chlamydiae
___________: different serovars are responsible
for different diseases
1) _________ (leading cause of blindness in developing
countries)
Sexually transmitted diseases
2) _________ ________ (most common STD in
U.S.)
3) lymphogranuloma venerum
Chlamydia trachomatis: trachoma nongonococcal urethritis Genera: Chlamydia Phylum: Chlamydiae
mild form of pneumonia
Chlamydophila pneumoniae
Genus: Chlamydophila
Phylum: Chlamydiae
Respiratory disease
Psittacosis
Chlamydophila psittaci
Genus: Chlamydophila
Phylum: Chlamydiae
Describe the life cycle of the chlamydias
slide 93
Phylum ______________:
• Name is derived from their coiled morphology
• Motile bacteria (rotating axial filaments)
• Many Inhabit the human oral and vaginal
cavities
Phylum Spirochaetes
Most important pathogenic genera/species of spirochetes
Borrelia burgdorferi
Leptospira:
Treponema pallidum:
causative agent of Lyme disease; transmission from ticks or lice to humans
Borrelia burgdorferi
Phylum Spirochaetes
____________, transmission from animals to humans
through contaminated water
Leptospira: Leptospirosis
Phylum Spirochaetes
causative agent of Syphillis
Treponema pallidum
Phylum Spirochaetes
Motile bacteria; utilize two or more axial filaments (endoflagella) Allows the cell to rotate like a corkscrew, easily cutting through liquids
spirochetes
§ Gram-negative, rod-shaped, non-motile, non-endospore
forming bacteria
§ Common inhabitants of the GI tract (most substantial portion)
§ Some species found in gingival crevice
§ Cause infections at surgical sites, puncture wounds and
through perforated bowel
Phylum Bacteroidetes
Genus Bacteroides
Gram negative non-motile rods present in the mouth and
known for creating periodontal and tooth problems
Genus Prevotella
Phylum Bacteroidetes
What is a unique characteristic about Phylum bacteroidetes, what the genus that are found in it?
Includes several genera of anaerobic bacteria
Genus Bacteroides
Genus Prevotella
- Anaerobic phylum
* Often pleiomorphic but may be spindle-shaped
Phylum Fusobacteria
fuso
spindle
– Long, slender spindle-shaped rods, pointed at the ends – Are found in the mouth – May be involved in dental diseases
Genus Fusobacterium
Phylum Fusobacteria
More resistant to radiation than are endospores
(survive a radiation exposure 1500x the dosage
that would kill a human)
– Resistance to is due to rapid repair of radiation
damage, which also extends to chemical
mutagens
Deinococcus radiodurans
Phylum Deinococcus-Thermus
– Hot spring in Yellowstone National Park
– Source of Taq polymerase
Thermus aquaticus
Phylum Deinococcus-Thermus
Types of species found in Phylum Deinococcus-Thermus
Deinococcus radiodurans
Thermus aquaticus
Domain ________
Placed into 5 physiological (3) or nutritional (2) groups
_____________: often conventional morphology but can be
unusual
archae; extremophiles
high temperatures; >80 degrees
thermophiles
survive in extremely low pH and often high
temps
acidophiles
thrive in high salt concs
halophiles
oxidize ammonia for energy
nitrifying
anaerobic bacteria that generate
methane gas by combining CO2 and H2
methanogens
PCR indicates up to _________ different types of bacteria in a 1 gram soil sample. (_______
named thus far in Bergey’s)
• Many bacteria have not been identified
because they haven’t been cultured
– Need special nutrients
– Are a part of complex food chains requiring the
products of other bacteria
• Culturing is necessary to understand their
metabolism and ecological role
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