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142 Cards in this Set
- Front
- Back
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Generally, how big are rod cells?
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1-2 um rods
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Generally, how big are spherical cells?
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.5-1 um spheres
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Describe Corynebacteria diphtheriae
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precipitates tellurium on tellurite blood agar
chinese character/snapping division club-shaped use gram stain on |
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Describe Streptomyces
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actinobacteria
crusty and threadlike use gram stain on |
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Describe Bacillus/Clostridium
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both form endospores, which can be viewed by phase microscopy
Bacillus is aerobic and is catalase positive Clostridium is anaerobic and is catalase negative |
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Describe Klebsiella pneumoniae
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grow on TSA
use negative stain to view forms glycocalyx |
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Describe Proteus mirabilis
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grow on TSA
has swarming motility in concentric circles view with gram stain |
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Describe Serratia marcescens
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forms red color when grown at 30 degrees
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Which organism contains the TOL plasmid?
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Pseudomonas aeruginosa
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Describe saccharomyces cerevisae
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yeast
eukaryotic grown on BCG agar view with wet mount |
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Describe Salmonella
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H2S positive
causes typhoid fever and food poisoning |
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Describe Shigella
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H2S negative
causes dysentery |
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Describe Vibrio
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bioluminescent
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Transient bacteria are...
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bacteria from dust and soil that don't belong on your skind
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Resident flora are...
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bacteria that belong on your skin
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Resolving power
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the ability to show close objects as distinct entities, more important than magnifying power
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3 Properties of Aqueous Suspensions
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bacteria retain natural size and shape
natural arrangement of group of cells preserved possible to observe motility |
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Brownian motion
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subtle, non-directional movement, caused by cells being bombarded with water molecules
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Dowfalls of spread, pour, streak plating
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spread: can't use volume over .2 mL
pour: can't pick colonies properly or count/see them streak: can't do a colony count (not quantatative) |
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Asepsis
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absence of infectious organisms
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A turbid culture contains:
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ten to the seventh cells per milliliter to five times ten to the ninth cells per milliliter, in stationary phase, in a rich medium
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95% values in a Poisson distribution are
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plus or minus (two times the square root of the mean)
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What do simple stains use to stick?
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electrostatic dye adhesion
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Gram positive bacterial peptidoglycan
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is thick, and physically retain the bond, a dehydrating alcohol physically compresses the pores, holding in the dye
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Gram negative bacterial peptidoglycan
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is thin, and can't hold the dye, because it can barely enter
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Minimal media
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has the basic requirements for growth
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Enriched media
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usually undefined, more than minimal nutrients for growth
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Selective media
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allows growth of some while inhibiting others
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Differential media
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distinguish based on reactions on media
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Auxotrophs
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nutritional mutants
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Colors in Durham tubes
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green is normal
yellow indicates acid |
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What do you filter?
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heat liable nutrients
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How long do you autoclave?
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15 minutes
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Binary fission results in?
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exponential growth
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Turbidity is measured as
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optical density
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When you graph turbidity over time, X and Y are?
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X is time
Y is ln OD |
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What are the four phases of growth?
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lag, log, stationary, and death
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The slope of the log phase is also
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u or specific growth rate constant
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Generation time
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time it takes for a bacteria to double in number
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Lambert Beer Law/ Equations
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A =2-log%T
ln X - ln Xo = u (t-to) u=ln2/g |
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Glucose can be used in cells as a source of
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carbon and energy
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Growth Yield
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Y = (X - Xo)/C
Y = yield X = mg/ml at stationary phase Xo=mg/ml at inoculation C = concentration of limiting nutrient |
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Catabolism
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series of enzymatic reactions needed to convert a carbon source to a variety of intermediates, generate reducing power, and produce utilizable energy
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Sugars have a
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large negative free energy charge (delta G) from complete oxidation to Co2 from H20
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Catechol 2,3 dioxygenase
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important enzyme involved in catabolism of aromatic compounds, produces yellow color, found in Pseudomonas putida
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Beer Lambert for activity
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A = ecl
c- concentration e- extiction coefficient l-length of light in cuvette |
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Activity
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umol/minutes
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Specific Activity
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umol/minutes all over mg protein
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Enrichment depends on what two unique properties of bacteria?
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1. capacity for rapid exponential growth
2. extensive metabolic diversity, including ability to grow under a variety of physical conditions |
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Biofilms are never
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biocultures, due to swimming bacteria
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Methyltrophs
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either utilize methanol, or methanol and other sources of carbon (serine or RuMP)
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Homolactic bacteria
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only produce lactic acid
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Heterolactic bacteria
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produce lactic acid and C02
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Lactic Acid Bacteria Enrichments rely on
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presence in nutrient rich environment without oxygen
and ability to grow in presence of sodium azide, a respiratory inhibitor |
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Lactic Acid bacteria are plated on what, why?
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CaCO3, because the acid turns the cloudy media clear
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Actinomyces enrichment depends on what
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1. ability to hydrolyze starch and use teh produced sugars as a source of carbon and energy
2. to use nitrate and or organic nitrogen (casein) as a nitrogen source rather than ammonia |
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Lactic acid bacteria generally
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are gram positive rods that lack cytochromes, so they are not sensitive to azide (respiratory inhibitor)
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Tween-80
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source of fatty acids and vitamin thymine, needed in minimal media for lactics to grow
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Actinomyces enrichment
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produce amylases, that hydrolyze starch
have nitrate reductase in their transport chain which allows them to grow on casein |
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Phylogenetics
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classification by presence or absence of certain genes
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Staphylococcus
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saphrophyte
skin parasite white or orange on media facultative anaerobe salt tolerant to 7.5% requires vitamins produces catalase |
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Catalase
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protects cells from accumulating H202, in toxic form of 02
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Staph aureus
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pathogenic, coagulase positive
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Staph epidermitis
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nonpathogenic, coagulase negative
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Streptococcus
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aerotolerant anaerobic
saphrophyte mucoid catalase negative salt tolerant to 6.5% has superoxide dismutase,so can grow in air |
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Hemolysis
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beta = full
alpha = partial gamma - none strep always staph aureus always staph epid sometimes |
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Facultative anaerobes
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grow in either, but better in air
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Thioglycollate is made from
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.5% agar
sodium thioglycollate, a strong reducing agent |
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S. pyogenes
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aerotolerant
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P. vulgaris
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facultative anaerobe
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C. perfringens
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obligate anaerobe
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E. coli
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facultative anaerobe
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P. aeruginosa
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aerobe
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Hetero/homo lactic table
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p vulgaris and e coli produce acid and gas, serratio produces only acid
all ferment on glucose ecoli cant ferment on sucrose only ecoli ferments on lactose p. vulgaris doesnt ferment on mannitol |
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Simmons Citrate
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an agar that is normally blue, turns green when acid is taken up
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Enterics
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gram negative, nonsporulating rods, facultative anaerobes, motile
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MacConkey Agar
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lactose with a small bit of glucose
ph indicator neutral red acidifiers turn red, others colorless crystal violet selecting agent against gram positive cocci |
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SS Agar
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bile salts, sodium citrate, brilliant green to inhibit coliforms
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EMB agar
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eosin methylene blue
turns coliforms metallic green due to the bacteria producing acid |
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Good fecal indicator
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present in feces, but not in uncontaminated environment
easily cultured in lab, but not in water can be identified on differential medium |
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Kiby-Bauer disk diffusion uses which agar, why?
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Mueller-Hinton cause it's standardized
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Shigella antigen testing
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aggultination to antibodies because they are divalent
four species but many strains |
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Lancefield antigen testing of strep
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unique teichoic acids and polysaccharides in cell walls
uses beads usually only done on b strep |
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Steps to isolation of auxotropsh
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1. mutagenesis to increase random mutation
2. enrichments of mutants usually using penicillin to kill prototrophs 3. sceen- place cells on enriched/supplemental media to support mutants, growth on minimal media to detect autotrophs |
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Insertional mutants
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dont revert as frequently as point mutations
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TnphoA'2
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transposon, not site specific recombinase
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bacteriophage lambda
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used to get tnphoa'2 into cell
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How does lambda get inserted into the cell?
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through lambD maltose import porin
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Reporter gene
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used to monitor transcription of operon
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Reporter gene for lambda
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lacZ
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What is the selective marker in lambda
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tetracycline
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Suicide vectors...
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can't replicate, because the OriC is deleted
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Osmoprotectants are...
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highly soluble
nontoxic able to accumulate at high concentrations |
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Three osmoprotectants are
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proline, glycine betaine, Kglutamate
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What are the components of the ProU system?
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ProX is the periplasmic binding protein
W and V transport system |
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ProU activity increases in the presence of
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NaCl, sucrose, nonsoluble molecules
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In Salmonella, what is inserted to null ProU?
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lacZ
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PutP is used
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in low proline, but inhibited at high osmotic strength
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ProP is used
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at high and low osmotic strength, but doesnt bind with high affinity to proline
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ProU is used
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functions preferentially at high somotic strenth for the uptake of osmoprotectants
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Alkaline phosphotase
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in periplasm removes phosphate groups from organic molecules
inducible in low phosphate media |
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SecB
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recognizes regions of alkaline phosphatase monomers to facilitate its passage into periplasm
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Leader region
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hydrophobic positively charged peptide region which helps anchor the sequence to the membrane
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Chaperones
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keep proteins from being folded
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Cell Fractionation
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SDS is a detergent whcih desoluizes membranes
Chloroform lyses outer membreanes, dissolves lipids lysozymes dissrupt NAT/NAG in peptidoglycan osmotic pressure then lyses the cell sonicating |
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Chloroform releases
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the periplasmic fraction
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Lysozyme releases
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the cytoplasmic fraction
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Quoromones are produced
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by LuxI
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Quoromones are sensed
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by LuxR
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AHL stands for, is present in
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acyl homoserine lactone, present in gram negative bacteria
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In gram positive bacteria, the quoromone is
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a peptide
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Being what allows AHL to pass through the membrane?
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acylated
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What is the second autoinducer?
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boron furanone
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H2S production
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uses various sulfur-containing compounds to differentiate enteric bacteria, sometimes producing black precipitate
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Indole
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if it can synthesize tryptophanase, it converts tryptophan to indole
the tester for this is dimethylaminobenzaldehyde, which is red when positive |
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KCN inhibition
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some bacteria have cytochromes not inhibited by cyanide...they are inoculated into a cyanide media, and if cloudy after while, then are resistant
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Methyl Red
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pH indicator for fermenters
if below pH 4.3, red because of acid if above, yellow |
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Nitrate Reduction
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some bacteria can use nitrate as terminal electron acceptor, instead of oxygen
grow in potassium nitrate, with alpha napthaline and sulfanilic acid if nitrate has been reduced, it will turn red, unless it has been reduced to a gas...then you add zinc, and if it doesnt turn red, it has become a gas |
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Voges Proskauer
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butanediol fermentation
add KOH and alpha-napthol acetoin converted to diacetyl, and is pink |
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Decarboxylase
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when carboxylic acid groups are converted to C02
add bromcresol purple to indicate pH rise positive tubes purple negative tubes yellow |
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Oxidase
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test presence of cytochrome c with tetramethy p phenylenediamine
and place on disk positives are purple |
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Phenylalanine deaminease
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removes NH3 from amino acid, forming carboxylic acid, add phenylalanine and ferric chloride, positive result is green
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urease
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urea and phenol red, if urea is hydrolized to produce alkalines, it turns red
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gram negative rod with aerobic metabolism, green
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pseudomonas
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aerobic metabolism without catalase or superoxide dismutaste
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microaerophiles
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nitrate in actinobacteria enrichment is used as
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an electron acceptor
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serology
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classifying strains of bacteria basedon their antigen sites
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o-antigen
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the antigen site in gram negative LPS
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catechol 2,3 dioxygenase can be transferred on
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the tol plasmid
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baciullus thuriengensis
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is a crystal
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static biofilm
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pond or bog
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dynamic biofilm
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flowing water
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Methyltroph pathways
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serine- more than just methanol
RuMP-just methanol |
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Which is more virulent, beta or alpha hemolysis?
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beta
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Kovac's reagent
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part of indole test
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zinc
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part of nitrate reduction test
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azide
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respiratory vs. fermentation tests
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electron accepting dye
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part of oxidase test
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phenylpthaleine (alkali indicator)
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part of urease test
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Defective oriR6K
these plasmids require pi to replicate why use it |
the vector would need to insert its dna into a host cell to be replicated
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How would you replicate a plasmid with oriR6K when you need to propagate it?
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use a propagation host with a pi gene
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Preventing lambda from lysing the host is done by
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the lambda pam three mutation -> no replication
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