Lectures 1-12 Flashcards
Cell mass method
Assume that the biomass corralates to the number of cells and use either the wet or dry weight as indication of growth amounts
DNA hybridization crosslinking
Uses test DNA bound to a membrane and a labled probe DNA, if the probe DNA sticks to the target the closer it is to the test DNA
Streptococcus
Low GC, gram+ bacteria, they are faculative aerobes and live in the mouth and upper respritory tract, non motile, form chains of coccus and do no produce endospores. Dividied into Pyogenic, Oral, and other
Alpha proteobacteria example
Rickettsia rickettsiae, obligate intracellular parasite transmitted by ticks and are non motile outside of the cell but within the cell can use the cytoskeleton of host to move(ROCKY mountain spotted fever)
Flagella strucutre
Rigid filament built in a helical shape made from flagellin monomers growing from the tip down and is attached to the hook
Spore
Specialized structure of an organism that can be used for dissemination or survival during adverse conditions, can also be used in reproduction
Molecular data and relatedness
1)Protein shapes
>3d structure such as reaction with antibodies, amino acid sequence, whole cell protein profile
2)Nucleic acid content
>compares variable regions for closely realted species allowing for rich data and deduction of evolutionary traits
Phycobilisomes
Granules found on infolded membranes that contain phycocyanin and phycoertherin which transfer electrons to PS2.
selective media
used to select for the growth of a particular “selected” microorganism. For example, if a certain microbe is resistant to aparticular antibiotic (e.g., novobiocin), then that antibiotic can be added to the medium in order to prevent other organisms, which are not resistant, from growing
Mechanism of flagella movement
Flagellum act similar to a boat propeller and is powered by a H+ gradient
Neutrophiles
Optimal ph 5.5-8.0
Fermentation pathway used by Pseudomonas
Uses Fe3+ as the electron acceptor and reduces it into Fe2+
Differential media
a type of media (usually of a solid or semi-solid consistency) used to distinguish between bacterial cultures based on their biochemical properties.
Macroneutrients of microbes
C,O,H,N,S,P (mg/L) and are used in lipids,proteins, carbs, and nucleic acids
K+,Mg+,Ca2+,Fe3+ cations used as enzymes and cofactors
Pros and Cons of Complex media
Pros: cheap, easy to prep, grows a variety of microbes
Cons:Cannot determine specific nutritional growth requirements
Lot- to -lot variation
bacteriorhodopsin
Light driven proton pump used to make energy for halobacteria
Barophillic
Microbes evolved for high pressure with strengthened cell walls
Redox reactions
Release of energy from a source using a reductant which gives electrons and an oxidant which accepts the electrons
Halobacteria
Bacteria that love salty enivorments needing around 1.5M of salt minimum to survive, living in the dead sea and great salt lakes they have cell walls that are dependant on salt. Also use fewer hydrophobic amino acids and more acidic amino acids on the outside to attract cations and form hydrates.
Psychrophiles
optimal temp <15
Ways to create heritable changes in bacteria
1)Mutations
2)Conjugation
3)Transformation
4)Transduction
5)Genetic engineering
Hypertonic solutions
water flows out of the cell leading to dehydration, hallophillic bacteria combat this by accumulating K+ ions intracellularly
Stationary phase
no net increase in live biomass, growth decreases due to limited nutrients or toxic buildups
Characteristics of phenetic classification
Morphology, biochemistry, habitat
Craig Venter experiment
Used a computer to create the genome of a bacteria and inserting it into a cell creating a functions organism proving DNA is what makes life
Pure cultures
Progeny of a single cell
Francesco Redi experiment
Demonstrated that the presence of maggots in putrefying meat does not result from spontaneous generation but from eggs laid on the meat by flies
Crenarchaeota
Archea that live in extreme temperatures, hydro thermal vents, and ocean ridges. They rely on sulphur as their electron acceptor or as an electron source.
Possible out comes of transfer of DNA from exogenote to endogenote
1)Integrate into chromosome of bacteria
2)Does not integrate and form a partial diploid that will replicate
3)Partial diploid that will not replicate
4)Exogenote is degraded via exonucleases
Chemolithotrophy
Process of getting elctrons and energy from oxidation of molecules other than NADH
Products of fermentation
1)Lactic acid ex.Lactis bacillus
2)Formic acid ex. Salmonella
3)Ethanols
Proteobacteria classes
1)Alphaproteobacteria,
2)Betaproteobacteria,
3)Gammaproteobacteria,
4)Deltaproteobacteria
5) Epsilonproteobacteria.
Where alpha-gamma only use PS1
Mesophiles
20-45 optimal temperature
Indirect evidence of H.Pylori causing gastritis
1)Location- occurs near sites of gastritis
2)Age distribution- more old people have stomach inflammation and H.Pylori is more common in old people
3)Epidemiology- gastric biopsies find a link
Synthetic media
Media with specific amounts of known nutrients with each component manually chosen containing a buffer+amino acids_ and trace elements
Germ theory
One germ forms one disease
Species
An arbitrary defined group of organisms that posses a high degree of similar charachteristics
Glycolosis
Occurs in the cytosol and involves the breakdown of glucose into pyruvate then into acetylcoa while generating NADH, ATP, and CO2
Radiation
Form T-T dimers that can be repaired but often cause errors, ionization radiation breaks the back bone of DNA
How does gram staining work
Gram-positive microorganisms have higher peptidoglycan content retaining the crystal violet, whereas gram-negative organisms have higher lipid content
Mixed acid fermentation
Pyruvate is converted into ethanol, Co2, and mixed acids
Thermophiles
55-65 optimal temperature
Organotrophs
Reduce organic molecules
Fermentation
Energy yielding process which an organic molecule is oxidized without an exogenous electron acceptor usually using pyruvate or pyruvate derivatives instead
Heterolactic fermentation
Heterolactic fermentation, yields carbon dioxide and ethanol in addition to lactic acid, in a process called the phosphoketolase pathway
16sRRNA and identification
Because the 16s rRNA sequence is ubiquitous in bacteria and archaea, it can be used to identify a wide diversity of microbes within a single sample and single workflow.
Carl Woese discovery
he uncovered the ‘third domain of life’. He achieved this by defining Archaea (a group of single-cell prokaryotic organisms) – by phylogenetic taxonomy of 16S ribosomal RNA, a technique pioneered by him.
E0
Equilibrium constants for the reaction, the tendency for the donor to lose electrons
Streptococcus pyogenes
Cause the disease Strep throat, rheumatic fever, scarlet fever, flesh eating disease
Numerical taxonomy
Comparison of relatedness by building a matrix between pairs based on traits with two factors Ssm=matching of traits including traits that do not exist in both species
Sj=matching of traits that ignores absent traits between strains
Broad spectrum antibiotics
Kills or inhibits the growth of both G+ and G- bacteria
Proteobacteria
Largest and most diverse of bacteria with a range of physiologigy and habitat, they are all gram negative bacteria and are believed to have come from purple photosynthetic ancestors
Grows in aw of 1 ex.blood
Gram negative bacteria, nonhalophiles
Three main nutrient types
1)Energy
2)Electrons
3)Carbon
Citric acid cycle
Breakdown of Acetyl COA to produce ATP,CO2, and FADH2 and NADH
Clostridium
Has two species, botulinum and sporangenes. Despite sharing 95% similarity they are seperate species because botulinum produces a deadly poison and so we have chosen to separate them.
High GC bacteria examples
Propionibacterium, mycobacterium, streptomyces
Chemolithotrophy pathway of nitrosomonas
Uses NH4+ as the e donor and O2 as the acceptor producing H2O and No3-
Endospore resistances and weaknesses
Resistances:Heat, desiccation, UV light, Y radiation, extreme temperature, extreme pH
Weakness:autoclave at 121C and 15psi
Chemolithotrophy pathway of Alcaligenes
Uses H2 as the e donor and O2 as the electron acceptor generating H2O
Endospore locations
Central-center of the cell
Subterminal- appears between the middle and the end of the cell
Terminal- appears at the end of the cell
Swollen sporangium- form a pinhead shape
Exponential Phase
Period of balanced growth with a consistent doubling time
How does H.Pylori get nutrients from the stomach
1)VacA: causes epithelial pores to from in the stomach cells siphoning nutrients
2)Inject bacterial proteins CagA to make cells leak nutrients
4 methods to determine microbial growth
1)Counting under microscope
2)Cell mass
3)Spectrophotometry
4)Cell constituent concentration
Intercalcating agents
Ex.Acridine orange, intercalcuate into double stranded DNA and forms bulk legions that are often repaired incorrectly
Butanediol fermentation
2,3 Butanediol is produced at varying levels in aerated fermentations as long as the dissolved oxygen level is limiting
Water activity formula
Vapour pressure of sample/vapour pressure of water(1)
Antonie van Leeuenhoek
Leeuwenhoek is universally acknowledged as the father of microbiology. He discovered both protists and bacteria as he developed a simple microscope using only a single biconvex lens.
Microneutrients
Ni+,Co2+,Cu2+,Zn2+,Mn2+ (μg/L) required in enzymatic activities they are found in nature at levels that they do not slow or limit microbe growth
Fermentation pathway used by enteric bacteria
NO3- acts as the acceptor and is reduced into NO2-
Freshwater protozoans adaptation
Have contractile vacuoles that pump water out of the cell
Homolactic acid fermentation
one molecule of glucose is ultimately converted to two molecules of lactic acid
Streptococcus mutans
Part of the mouth flora and causes dental cavities as its a homolactic fermenter leading to breakdown of enamel
Strain
Isolate arisen from a single cell
Methods to mutate DNA
1)Base analogues with purine and pyrimidine derivatives
2)DNA intercalcating agents
3)Alkylating agents
4)Radiation
How does H.Pylori attack the human stomach
Motile:able to swim with flagella
Mucinase:breaks down mucas
Urease:Converts Co2+NH3 from urea to create an alkaline cloud making it more basic
Complex media
Formed from protein hydrolysate of beef or soy, water soluble beef or yeast extract, vitamins and trace elements plus a carbon source like glucose
Mutant screening
1)Positive selection->plate survivors from mutagen on a slective media, only the ones that can survive have the mutation you want
2)Negative selection-> plate survivors onto a master plate and stamp onto a control plate and a modified plate. Look for colonies that died on the modified plate and swatch them from the master plate
Euryarchaeota phsyiological groups
1)Methanogens
2)Halobacteria
3)Thermoplasms
4)Extremely thermophillic Sulphur metabolizers
5)Sulphate reducing euryarchaeota
Kochs Postulates
1)Microorganism must be present in every case of the disease
2)The suspected microorganism must be grown in pure culture
3)Same disease must result when isolate microorganism is inoculated into host
4)The same microorganism must be isolated again from the host
Nitrogen fixation via cyanobacteria
N2->NH3(NH4+) using ATP as energy, NADPH as an electron source, and nitrogenase to catalyze the reaction
Calculating growth rate
LogNt-LogN0/ time x log2
Dark reaction
Converts NADPH+ATP+CO2 into organic carbon
Beta proteobacteria example
Myxococcus xanthis, live in soil and form colonies when nutrients are low, capable of secreting many secondary metabolites
Bdellovibrio bacterivorus, parasitize other gram negative bacteria,live in sewage and freshwaters
Important features of the G+ cell wall
Contain Techoic acids and lipoteichoic acids which anchor the cell wall polymers of glycerol and ribotol. They give a negative charge and improve the rigidity of the cell wall
Fermentation pathway used by denitrifying bacteria
Utilizes NO3- as the electron acceptor but further reduces the No2- into N2
lophotrichous
Lophotrichous bacteria have several flagella that are all present at the same place on their surfaces and work together to propel the bacteria in a certain direction
Horizontal gene transfer
The method that genes are transferred from one mature organism to another
Acidophiles
Optimal ph 0-5.5
Cell constituent method
Measure the components from lysed cells and use it as a basis to estimate amount examples include proteins,dna,NADPH
Peptidoglycan
The basic structural unit of the cell wall forming from NAM and WAG backbones, peptide chains, and peptide interbridges
Difference between eukaryotes and the bacteria and archeabacteria domains
1)Have a true nucleus bound by a membrane
2)Specialized organelles
3)Have histones and use chromosomes instead of a circular DNA
4)Transcription and translation occur at different times and locations
Process of gram stain
1)Add alcohol and sterilize the slide
2)Streak the plate and then the slide and heat fix the bacteria onto it
3)Add crystal violet for 60 seconds then wash and flood with iodine for 60 seconds
4)Wash with alcohol or iodine
5)Stain with saffron
Dendrogram
a diagram that shows the attribute distances between each pair of sequentially merged classes where nodes show the S value between branches
Species higher species and bacteria
Higher organisms: Reproductively isolate group that can produce viable offspring
In bacteria:Share more than 80% genetic similarity
Lithotrophs
Reduce inorganic molecules
Function of the prokaryotic cell plasma membrane
1)selective permeability
2)Site of transport proteins
3)Site of respiration/photosynthesis/lipid synthesis
4)Contain receptors to sample and detect molecules in the enviroment
Aerobic respiration
Utilizes oxygen as the final electron acceptor in the ET chain
Mechanism of siderophore movement of Iron
1)siderophore is secreted from bacteria and binds extracellular iron
2)siderophore complex is connected to receptor and Fe3+ is turned into Fe2+
3)Fe2+ is able to move in the cell via porins
Gram negative cell layers
1)Outer membrane
2)Thin Peptodoglycan layer
3)Cytoplasmic membrane
Biovar
Strains that differ in biochemical or physiological properties
Fermentation pathway used by desulfovibrio bacteria
Uses SO4^2- as the electron acceptor and reduces into H2S
Lag phase
Period of metabolic adjustment to new conditions, the growth rate gradually increases and DNA and protein synthesis is occurring for replication
Ways to select for a mutation
1)Use strains deficient in DNA repair mechanisms
2)Increase the mutation rate by exposing microbes to mutagens
grows in aw 0.95 ex.bread
gram positive bacteria, some fungi, and most protists
Ignaz Semmelweis
the first physician in medical history who demonstrated that puerperal fever (also known as “childbed fever”) was contagious
Pyogenic streptococcus
Bacteria which carse a pattern of RBC lyses, can be detected in blood agar by formation of clear areas near colony
Spectrophotometry
Suspension of organisms absorbs light around 550-600nm range, and the amount of absorption correlates to proportion of bio mass allowing for estimations to be made
Endospores
spores that are extremely heat and chemical resistant found in some G+ bacteria
Organotrophs
Gain electrons from organic molecules
Prokaryotic DNA
Form double strands in a singular circular chromosome where the chromosome is larger than the bacteria requiring super coiling to make fit
Sterols in prokaryotic plasma membrane
Stabalize the fluidity of the plasma membrane
Base analogues with purine and pyrimidine derivatives
Incorporates into DNA like a T but base pairs G instead of A
Nutrient uptake pathways
1)Simple diffusion
2)Active transport
3)facilitated diffusion
Bacteria cytoskelton proteins and their homologous
Bacterial FtsZ- microtubule (MT)
Mreb- Actin fillaments
Pseudomurein
Peptidoglycan like polymer that uses L-amino acids instead of D-amino acids, N-acetylmuramic acid instead of NAM, B 1-3 linkages
Pros and cons of synthetic media
Pros:Tell you specific nutritional requirements of a microbe, consistency
Cons:Expensive and labour intensive
Important features of G- cell walls
1)O-specific side chains that stimulate immune response
2)Outer membrane that regulates immune response and acts as a selectively permeable membrane
3)Porins: allow passage into membrane
4)Brauns lipoproteins found in the peptidoglycan layer
Death phase
Net loss of live biomass, programmed cell death or toxic metabolite deaths
Ways microbes can change their environmental ph
1)Fermentation of organic acids to decrease pH
2)Sulphate reducing bacteria turn So42- ->H2SO4 increasing ph
Counting method
Use a stain and a calibrated slide chamber to extrapolate the values of bacteria present
Morphovar
Strain that varies in morphology
Hopanoid
determine bacterial outer membrane order in a manner analogous to sterol ordering in the eukaryotic plasma membrane but lack cholesterol
Half reaction coupling example
NADP+ + H+ +4e- ->NADPH (E0’=-0.32, donor)
O2+4H+ +4e- ->H2O (E0’=0.81, acceptor)
Where the difference in energy is ΔE0 and drives the reaction forward
Why is iron hard to obtain in nature
It naturally oxidizes into rust making it biologically unavailable
Non coding regions in bacteria DNA
Used as a binding site for proteins which control transcription
Hypotonic
Water flows into cells making them lyse, to get around this bacteria,fungi,algae have cell walls
Streptococcus pneumoniae
Cause Pneumonia, middle ear infections, meningitis, and pink eye
Bacterial mRNA
1)No 5’ cap
2)no Poly a tails
3)polycistronic
Mutation types
a)Point mutations- mutations at a single nucleotide can be silent, missence, or nonsense
b)Frame shift- loss or gain of a base pair leading to codon reading frame changing
Bacteria DNA vs Archea DNA
Bond DNA with non histone proteins where as archea uses histones to bind DNA and form nucleosomes
Green and Purple photosynthetic bacteria
Uses only PS1 and bacteriochlorophyll(BCHL) at 860-1000nm, live lower in the water table and uses H2,H2S, and S0 as electron donors
Steps in energy generation
1)Glucose undergoes glycolosis and turns into pyruvate
2)Pyruvate breaks down into acetyl COA and participates in the citric acid cycle
3)FADH2 and NADH are generated and participate in the electron transport chain to generate ATP
4)NAD+ and FAD+ are generated
Electron acceptors for each energy generating method
1)Fermentation- NADH
2)Aerobic- O2
3)Anerobic- Co2,No3-,So4^2-
4)Chemolithotrophy-O2, No3-
How do microbes get iron?
1)Secrete siderophore, low MW molecules that complex with iron to bring it into the cell vias association with the siderophore receptors
2)Hemolysins, lyse RBC or live within RBC
Steps in electron transport
1)Photon hits chlorophyll molecules in photosytem 2 resonance will activate all the chlorophyll, in the reaction centre electrons are energized via resonance reaction
2)Plastiquione picks up electrons and photosystem 2 regenerates using break down of water
3)PQ moves electrons to cytochrome BF complex and electrons are move into the cytoplasm
4)PC moves electrons to photosystem 1
5)Electrons are re excited by photons which are transferred from ferrodoxing to FAD making NADPH
Flagella movement types
Run->Counter clockwise spinning
tumble->Clockwise spinning
Louis Pasteur experiment
Pasteur boiled a meat broth in a flask that had a long neck that curved downward, like a goose. The idea was that the bend in the neck prevented falling particles from reaching the broth, while still allowing the free flow of air. The flask remained free of growth for an extended period. When the flask was turned so that particles could fall down the bends, the broth quickly became clouded. Nothing grew in the broths unless the flasks were broken open, showing that the living organisms that grew in such broths came from outside, as spores on dust, rather than spontaneously generated within the broth.
Unique features of archaebacteria
1)Cell walls do not contain peptidoglycans or glycoproteins
2)different RNA polymerase and TRNA structure
3)Unique membrane lipids where fatty acids are linked to the glycerol backbone as ethers instead of esters
Testing for endospores
1)Direct staining
2)Boiling sample for 10 mins and see if anything survives, if it does that likely is due to the endospore germination
Extremely thermophilic Sulphur metabolizing archaea
anaerobic chemoorganoheterotrophs that use peptides and carbohydrates to reduce sulphur to sulfide. Optimal growth at 88-100C
Characteristics of fermentation
1)Regenerate NAD+ so it can be used as an electron acceptor
2)No electron transport chain
3)No oxygen required
How to detect flagella
1)Semi solid agar (indirect)
2)Electron microsopy (direct)
3)Light microscopy
Live cycle of Bdellovibrio bacterivorus
1)Attacks gram negative bacteria using extracellular flagella to move
2)Secretes lytic enzyme and enters the host
3)Enters host in around 10 seconds and drops flagella
4)Growth inside of host and rupturing of host cell
Electron transport chain
Reaction of NADH and FADH2 into NAD+ and FAD+ generating ATP
Alkalophiles
Optimal ph 8.0-11.5
Barry and Warren experiment
Barry gets a biopsy proving no gastritis, then intentionally infects himself with pure H.Pylori, biopsy again and he has gastritis and H.pylori, able to grow H.pylori from his sample. When H.Pylori was killed with antibiotics he had no more gastritis
Bacterial cell wall functions
1)Allows for identification
2)Determine certain aspects of cell shape
3)Prevents osmotic lysis
4)Protects from toxins
Spirochetes
Organism with many flagella originating from each end of the microbe with each flagella originating from periplasmic space
Autotrophs
Gain carbon via fixation of HCO3- or Co2
Chemotaxis
A pattern of microbial behaviour in which a microbe moves towards or away from a chemical attractor
Phentic classification
Uses expressed traits, observed characteristics, and morphology to compare species
Hook
Universal joint that links the flagellum to the motor basal body, made of several proteins
How to change the direction of a flagella spin
1)Stimulus binds to G protein and MCP phosphorylates CHEA
2)CheY is phophorylated leading to a switch in the rotation of the motor from CCW to CW
cyclical phosphorylation
Alternate energy generating pathway when a bacteria lacks photsystem 2, instead passing the electrons between photosytem 1 and the cytochrome complex
Archeal flagella
Made of archeal flagellin which resembles pilli as they are not hollow and are thinner, using ATP as the driving force
Anatomy of endospore
1)Core and Core wall- holds the ribosomes and nucleic acids and cover in a pertidoglycan layer that will form the vegetative cell wall after germination
2)Cortex-around 1/2 the spore volume and contains peptidoglycan and salts that dehydrate the spore
3)Spore coat-many layers of cross linked proteins to resist chemicals
4)Exosporium-White delicate covering
amphitrichous
Having a single flagellum on each of two opposite ends
Narrow spectrum anitbiotics
Inhibits the growth of either G+ or G- bacteria ex. penicillium effective on G+
Environmental factors affecting microbe growth
1)Solutes and water activity
2)pH
3)Temperature
4)Oxygen
5)pressure
Phylogenetic classification
Classification based on evolutionary relatedness
Chemotrophs
gain ATP energy from organic or inorganic compounds
Actinobacteria
A phylum of bacteria that care the source of most antibiotics used in medicine today for their secondary metabolites
Gene transfers in eukaryotes vs Prokaryotes
Eukaryotes:required as part of meiosis between homologous chromosomes
Prokaryotes:non reciprocal transfers during conjugation,transformation or transduction
Methanotropes
Microbes that can grow using methane as its sole carbon and energy source
Methanogens
Generate energy via conversion of substrates into methane, they live in aerobic freshwater environments and animal gut biome. They lack peptidoglycan and instead use pseudomuren as a cell wall polymer
Why is it important to understand nutritional requirements of microbes?
1)Allows us to control their growth
2)Allows us to culture microbes in a lab
Post translational modifications in bacteria RNA
Interfering RNA sequences can bind nascent RNA and interrupt translation and other binding proteins
4 phylum of archea
1)Crenarchaeota
2)Euryarchaeota
3)Korarchaeota
4)Nanoarchaeota
Thermoplasms
Grow as 55-59 degrees and at 1-2 pH, they lack cell walls and instead uses glycoproteins, diglyceral tetraethers, lipid containt polysaccharides, and crenarchaeol for stablility. Also uses archeal histones.
Robert Hookes discovery
While observing cork through his microscope, Hooke saw tiny boxlike cavities, which he illustrated and described as cells. He had discovered plant cells!
Chemolithotrophy pathway of Thiobacillus denitrificans
Uses H2S and S as the electron donor and NO3- as the acceptor producing SO42- and N2
Grow in aw <0.60
Fungi, no longer able to grow bacteria
Alkylating agents
Ex. methyl nitroguanidine
Alkylates G and causes misrepairs in DNA
peritrichous
covered all over with uniformly distributed flagella
Cyanobacteria
Resembles higher plants with PS1 and 2 using phycobilins to absorb light 680-700nm and use H2O as its electron donor producing O2. They live in aerobic aquatic environments and move with slime layers, capable of fixing N2
How to differentiate live cells in a colony
Plating such that each colony arose from a single cell, this does come with the drawback that cells will sometimes clump leading to underestimation of cells
Lithotrophs
Gain electrons via oxidation of inorganic molecules
Gibbs free energy
ΔG0=-nFΔE0
n=number of electrons transfered
F=Farraday constant
ΔE0’= difference in energy between reactions
grow in aw 0.75
Halobacteria
Gram Positive cell layers
1)Thick peptidoglycan layer
2)Cytoplasmic membrane
The bacteria shapes
1)bacillus (rod-shaped)
2)coccus (spherical-shaped),
3)spirillum (spiral-shaped)
4)Filamentous(filament shaped)
5)Vibrio(curved rod)
Staphylococcus aureus
Live on our skin and are faculative aerobes, lack motility, form grape like clusters, lack endospores, give boils,abscesses,impetigo,food poisoning, pneumonia, and blood infections, LOW GC
Helicobacter pylori
Bacterium responsible for stomach ulcers in humans, they are found in the region next to the pyloric sphinctor of the stomach
Molecular GC content
Counting the GC content of a genome where higher GC content is more stable
MRSA
Methicillin resistant Staphylococcus aureus, must be killed with last resort drugs
monotrichous
having a single flagellum
Serovar
Strain that differs in surface antigens
Type strain
1st isolate of a species and is usually the one best characterized but not necessarily most common
Fox model of non reciprocal homologous recombination
1)DNA binds to homologous region
2)Donor DNA is unwound and base pairs the host
3)Donor DNA is nicked by host enzymes
4)Recipient DNA is nicked by host exonculease
5)Strand is Filled and ligated into host DNA
Light reaction
Uses electron transport to produce ATP+NADPH+O2
Water activity
a quantitative measure of water availability in the habitat. It is calculated as 1/100 the relative humidity of the solution when humidity is written as a percent
Low GC bacteria examples
Stapholoccocus, Streptococcus, lactobacillus
Anatomy of a prokaryotic cell
1)Ribosomes- found in the cytoplasm
2)Cell wall-strong polysaccharides and protein external the cytoplasm
3)Nucleoid- Area where DNA and associated proteins are associated
4)Inclusion bodies-aggregates of organic and inorganic material in the cytoplasm that stores nutrients
5)Pilli- protein tubes that extend from the plasma membrane and attach to surfaces
6)Vacuoles/Vesicles-allow aquatic bacteria to move up and down in the water table
Phototrophs
Gain ATP energy from sunlight
Hyperthermophiles
80-113 optimal temperature
Characteristics of H.Pylori
1)Has special adhesion proteins called adhesins that allow pathogen to bind to host tissue
2)Gram negative
3)Spiral rod shape
4)Uses flagella
5)Microaerophilic, likes O2 concentrations 2-10%
Chemolithotrophy pathway of Nitrobacter
Uses NO2- as the e donor and O2 as the electron acceptor producing H2o and No3-
Fimbriae (pilli)
Short helical protein filaments that emanate from the surface of the organism and mediate attachment to substrate and also mediate twitching mobility
Heterotrophs
Gain carbon from organic molecules
Z-scheme
Regular energy generating pathway where electrons move from part to part starting at photosystem 2
E0’
Standard reduction potential, it measures weather a particular compound will tend to accept or donate electrons at STP
Microbial growth in a closed system
Divided into four phases
1)Lag
2)Exponential
3)Stationary
4)Death
Fermentation pathway used by Methanogens
Uses CO2 as the electron acceptor and reduces it into CH4
How do spores survive extreme conditions?
Spore coat: protects the spore from chemicals and lytic enzymes
Inner membrane:imperable to many chemicals which damage DNA
Core: low water content, low pH, dipicolinic acid complex with calcium stabilizing DNA
Electron transport chain
Electron is transfered
1)Photosystem 2 (Oxygen)
2)Plastoqionone
3)Cytochrome complex
4)Photosystem 1
5)Ferredoxin(NADPH)
