Flashcards
bacteriology lab final
Cards in this deck (195)
- 1equation of nitrate reductionNitrate (NO3) -> nitrate reductase -> nitrite (NO2) -> nitrite reductase -> nitric oxide (NO) -> nitric oxide reductase -> nitrous oxide (N2O) -> nitrous oxide reductase -> nitrogen (N2)
- 2if working nitrate reduction backwards, o, how would enzymes changebonds are being oxygenated, so reaction would be mediated by oxygen rather than reduction
nitrite to nitrate --> mediated by oxidoreductase (or nitrate oxidase) - 3positive result of nitrogen reduction testred coloration in media without adding zinc
- if there is no color change and you add zinc, and the media STILL DOES NOT TURN RED = positive - 4negative result of nitrogen reduction testno color change before adding zinc
OR
if you add zinc and media turns red = negative - 5what does positive result of nitrogen fixation signify?without zinc -> organism has reduced nitrate to nitrite
with zinc -> no nitrate to reduce; no nitrite present in the medium; denitrification took place and ammonia or molecular nitrogen was formed - 6what does negative result of nitrogen reduction signify?without zinc -> organism was unable to reduce nitrate, OR organism was unable to denitrify nitrate or nitrite to produce ammonia or molecular nitrogen
with zinc -> unreduced nitrate was present - 7reagents of nitrogen reduction testsulfanilic acid and alpha-naphthylamine
-when sulfanilic acid is added, it will react with nitrous acid to produce diazotized sulfanilic acid; this reacts with alpha-napythylamine to form a red-colored compound - 8possible results of nitrogen fixation test (image)
- 9spectrophometrybacterial concentration and optical density are positively correlated
- 10spectrophometry equationgiven the absorbance (ABS) and photolength (L), the equation to solve for optical density (OD) becomes:
OD = ABS / L
- 11spectrophometry cell density and time graph
- 12nitrate reduction test procedure1) inoculate with loop
2) incubate
3) additional solutions - sulfanilic acid (A) and naphthylamine (B)
3) positive if red (nitrate to nitrite)
4) no color, add zinc --> if it doesn't turn red = positive, if it does = negative - 13methyl red vogues proskauer test procedure1) inoculate MRVP broth with your culture and incubate at 37 degrees C
2) perform VP test
3) perform methyl red test - 14voges proskauer procedure1) pipette 1.0 ml of MRVP broth into empty sterile tube
2) add 0.6 ml of alphanaphthol and 0.2 ml of KOH solution
3) shake tube well and allow it stand for 10-20 minutes
4) observe and record color - 15VP test positive resultred-brown color (acetoin + alpha-naphthol + KOH = red color)
- 16MR test positive resultif pH indicator (methyl red) is added to an aliquot of culture broth and pH is below 4.4 -> red color
- 17VP test negative resultyellow-brown color
(Barrett's reagent) alpha-naphthol + KOH = copper color - 18MR test negative resultif media turns yellow, the pH is above 6.0 and the mixed acid fermentation pathway has not been utilized
- 19what questions does MR test seek to answer?-whether organism can use glucose as substrate, which fermentation pathway can use to utilize glucose
-amount of acid produced by different bacterial species (All members of Enteriobacteriaceae can convert glucose to pyruvic acid by Embden-Meyerhof pathway) - 20what does partial reduction of nitrogen reduction test meanif a red color is observed after the addition of A and B, then the organism reduced nitrate to nitrite but likely not beyond that point (i.e. partial reduction)
- 21what does complete reduction of nitrogen reduction test meanif no color change occurs after the addition of each reagent (A, B, and zinc), then the organism completely reduced nitrate (i.e. nitric oxide, nitrous acid, or dinitrogen)
- 22color and result of MRVP test
- 23is mannitol salt agar selective, differential, or bothboth
- 24—positive result of mannitol salt agar
- 25—negative result of mannitol salt agar
- 26interpretation of poor growth or no growth on mannitol salt agar and presumptive IDorganism is inhibited by NaCl
- not Staphylococcus - 27interpretation of good growth on MSA and presumptive IDorganism is not inhibited by NaCl
- Staphylococcus - 28interpretation of yellow growth or halo on MSA and presumptive IDorganism produces acid from mannitol fermentation
- possible pathogenic S. aureus - 29interpretation of red growth (no halo) on MSA and presumptive IDorganism does not ferment mannitol; no reaction
- nonpathogenic Staphylococcus - 30what genus typically thrives on MSA?staphylococcus
- 31colonies that appear yellow on MSA ferment what?mannitol (positive result)
produce acidic byproducts of fermentation that lower pH of media
-acidity of media causes pH indicator (phenol red) to turn yellow - 32—Mannitol salt agar
- 33what broad class of bacteria are inhibited by MSA media?gram-negative
- 34—eosin methylene blue agar
-this plate specifically would be positive and green metallic sheen most likely indicates E. coli (based on rate of lactose fermentation)
- 35what kind of bacteria grow on EMB agar?gram-negative
-gram positive is inhibited by dye eosin and methylene blue added to agar - 36EMB agar principle
- 37EMB media differentiates bacteria based on their ability to fermentlactose
- 38what does result of EMB depend onamount of acid produced
-production of lactic acid prompts indicator dye (eosin) to appear either pink-brown or black-blue - 39—MacConkey
selective and differential
- 40—phenyl alcohol agar
-selective
- 41—blood agar
enriched media
- 42—tributyrin agar plate
negative on left and positive on right
- 43tributryin agar plates contain ______ ______ and are initially ________1) triglyceride tributryin
2) opaque - 44what does tributryin agar plate test ability ofwhether organism can produce an exoenzyme, LIPASE, that hydrolyzes tributryin oil
- 45what does lipase allow organism to doallows organism that produce it to break down lipids into smaller fragments
- 46positive result of tributryin agar platelipase-positive organisms will exhibit a clear zone around their growth
-tributryin has been hydrolyzed - 47—tributryin agar plates
positive on left and negative on right
- 48—milk agar (casein) plate
negative on left, positive on right
- 49what does milk agar (casein) plate test fordigestion of casein by proteolytic exoenzymes that are secreted outside of the cell
-ability of organism to produce exoenzyme CASEASE that hydrolyzes casein - 50—extracellular enzyme assay examples
- 51if bacteria can ferment lactose into lactic acid, MacConkey agar turnsreddish-pink
- 52what does MAC plate differentiate for and what is based ongram-negative
based on ability to ferment lactose - 53what does MAC plate select forgram-negative bacteria
- 54interpretation of positive MAC resultpH in surrounding media drops below 6.8, pH indicator (neutral red) elicits a response and facilitates bile salt precipitation within bacterial colonies --> causing colonies to appear pink
- 55what does crystal violet in MAC plate doinhibits growth of gram-positive cells
- 56procedure of gram stain1) prepare bacterial smear
2) flood bacterial smear with crystal violet for ~1 min (tilt off excess stain and gently rinse with water)
3) flood bacterial smear with iodine (mordant) for ~1 min (tilt off excess stain and gently rinse with water)
4) flood bacterial smear with ethanol (decolorizer) for 5-10 sec (DO NOT EXCEED 10 SEC)
5) flood bacterial smear with counterstain (safranin) for ~1 min
- 57how to differentiate between gram + and gram - cellsgram + appear purple/blue under microscope
gram - appear pink/orange under microscope (due to counterstain safranin) - 58biggest difference between gram + gram - cellspeptidoglycan layer
- 59comparison of gram + and gram - cells
- 60—serial dilution
- 61purpose of serial dilutionused to decrease a bacterial concentration to a required concentration for a specific test method
OR
to a concentration which is easier to count when plated to an agar plate. - 62CFU ml^-1 equationCFU/mL = (# of colonies observed on plate) / ([dilution factor] x [amount spread on plate])
- 63antibiotic resistance procedure
- 64what does Kirby Bauer plate test forinability/ability of organism to survive in the presence of a particular antibiotic
- 65antibiotic resistance is undergirded bygenetic machinery
- efflux pumps allow organism to shuffle antibiotic in and out without antibiotic binding to given region that would render cells inactive - 66interpretation of antibiotic resistance test-the larger the zone of inhibition (blue circle), the greater the impact of antibiotic on organism/mitigating growth of organism
-quantitative measurement of efficacy can come from measuring zone of inhibition
- 675 ways bacteria acquire antibiotic resistance1) restrict access to antibiotic by changing entryways or limiting number of entryways
2) get rid of antibiotic using pumps in cell walls to remove antibiotic drugs that enter cell
3) change or destroy antibiotic with enzymes, proteins that break down drug
4) bypass effects of antibiotic by developing new processes that avoid using antibiotics target
5) change the target of antibiotics (some drugs are designed to single out and destroy specific parts of a bacterium; germs change antibiotic target so that drug can no longer fit and do its job) - 68bacteria develop resistance mechanisms by using instructions provided byDNA
-resistance genes found within plasmids
-small pieces of DNA that carry genetic instructions from one germ to another= some bacteria can share their DNA and make other germs resistant - 69results of carbohydrate fermentation test
- 70proof that growth occurred in carbohydrate fermentation test is via (3) things1) turpudity
2) acid base indicator if the MO metabolites are acids and bases
3) gas production - 71what does carb fermentation test look forability of organism to produce gas
- 72how can carb fermentation test classify organismsbased on ability to produce either acid, ferment glucose at all, or to produce gas utilizing a certain carbohydrate
- 73substrate in carb fermentation testcarbohydrate
-action of organism on carb substrate results in acidification of medium, detected by pH indicator dye - 74citrate utilization test equation
- 75—citrate utilization test
positive on left (growth and color changes to blue)
negative on right (no growth and color remains green; similar to uninoculated)
- 76what is citrate utilization test used forto help differentiate species of family Enterobacteriaceae
-selective for bacteria that has ability to consume citrate as its sole source of carbon - 77pH indicator of citrate utilization testbromothymol blue
- 78carbon source and nitrogen source of citrate utilization testsodium citrate (carbon source)
NH4+ (nitrogen source) - 79citrate utilization test is done on _____ since ____ is necessary for citrate utilizationslants
O2 - 80when bacteria oxidize citrate,they remove it from medium and liberate CO2
- CO2 combines with sodium (supplied by sodium citrate) and water to form sodium carbonate = an alkaline product
- this raises pH, turns pH indicator a blue color and represents positive citrate test - 81____ is critical in citrate utilization test because it can combine with excess _____ and produces what1) CO2
2) sodium
3) carbonate molecule that will lower pH and turn media from green to blue - 82oxidase test results
- 83positive result of oxidase testcolony/bacteria spread on filter paper instantly turns deep blue/black within 10 seconds
-good indication that organism is producing oxidase enzyme - 84negative result of oxidase testcolor change does not happen on filter paper or TAKES LONGER THAN 10 SEC
- 85what does oxidase test test forability of organism to produce/express oxidase enzyme
- 86what kind of organisms will produce positive result on oxidase testaerobic organisms
going to be critical for ETC - 87organisms that use oxygen to utilize cytochrome oxidases, catalyze oxidation of cytochrome using oxygen itself produces whathydrogen peroxide
-can be relatively caustic to organisms - 88how to perform catalase test1) large amount of bacterial growth is transferred to microscope slide
2) 1 to 2 drops of hydrogen peroxide are applied and formation of bubbles or No Reaction is observed - 89what is the purpose of catalase testused to differentiate members of catalase-positive Micrococcaceae from catalase-negative Streptococcaceae
- 90positive result of catalase testorganism is capable of expressing catalase, then it will produce oxygen and water and as a result, bubbling happens from oxygen within 5 seconds after adding hydrogen peroxide
- 91negative result of catalase test
- 92what is fluid thioglycollate tube used foroxygen requirements
-inoculation of various tubes with different strains
-based on how strains grow in media (bottom, top, evenly, concentrated) gives insight into enzymatic capability and proclivity for oxygen or anaerobic environment - 93—obligate aerobe
-enzymes most likely depend on oxygen
- 94—obligate anaerobe
-organism is most likely catalase-negative and oxidase-negative
- 95—facultative anaerobes
-prefer oxygen but can thrive in oxygen-deficient environment
-will have one or the other (catalase and oxidase)
- 96—aerotolerant organism
-can tolerate oxygen but prefers anaerobic environment
- 97—microaerophiles
-prefer oxygen but only at small concentrations
-many growth-dependent enzymes/mechanisms will be sensitive to oxygen/aren't good at mitigating oxygen at higher levels
- 98enzyme involved in gelatin liquefaction testgelatinase
- 99—gelatin liquefaction test result
positive on top and negative on bottom
- 100purpose of gelatin liquefaction testgelatin is too large to enter a bacterial cell wall and thus extracellular enzymes must catabolize them into smaller components before they can be utilized
-possession of these extracellular gelatinases can aid in differentiation of bacteria - 101interpretation of positive result gelatin liquefaction testbacterium makes enzyme gelatinase (which optimally is produced at 25 degrees C, not 37 degrees C) --> gelatin is hydrolyzed and becomes a liquid
- 102is there indicator or reagent added to gelatin liquefaction test?none
simply solidification or liquefaction - 103composition of carbohydratesstarch is branching polymeric carbohydrate
consists of large number (poly-) of glucose molecules (-mers) - 104bonding of carbohydrates-covalently bonded together by glycosidic bonds
- 105what hydrolyzes carbohydrate bonds and howamylase
-split large starch molecules into smaller chunks (dextrins and maltose)
-dextrins are split until molecules of maltose are left (consist of 2 glucose molecules bound together)
-maltose is hydrolyzed by maltase which yields soluble glucose that can be brought into cell - 106composition of proteins and 2 types of proteins1) gelatin is technically incomplete protein because it lacks tryptophan but microorganisms still use it as a nutrient
2) casein is major protein in milk ("milk protein)
-polymers of amino acids - 107bonding of proteinscovalently bound by peptide bonds
- 108how are proteins hydrolyzed and by what- done by proteases
-steps of hydrolysis are called proteolysis
protein --> peptones --> polypeptides --> dipeptides --> amino acids - 109composition of lipids and subclass of lipidlarge macromolecules compounds that are used to store tremendous amount of energy
- subclass = triglycerides
--glycerol cap attached to 3 fatty acid chains - 110bonding of lipidsfatty acids are attached to each of the three carbons of the glycerol molecule with an ester bond through the oxygen atom.
- 111how are lipid bonds hydrolyzed and by whattriglycerides are hydrolyzed by lipases called esterases
- split fatty acid tails off glycerol cap
-once split off, fatty acids and glycerol can be brought into cell and further broken down so as to be run through Krebs cycle - 112composition of nucleic acidslong, chainlike molecules composed of a series of nearly identical building blocks called nucleotides
-each nucleotide consists of nitrogen-containing aromatic base attached to a pentose sugar, which is attached to phosphate group - 113bonding of nucleic acidsDNA and RNA both have phosphodiester and hydrogen bonds linking them
-phosphate group of DNA and RNA get linked with adjacent carbon atoms to form an ester linkage leading to formation of phosphodiester bond - 114how are nucleic acids hydrolyzed and by whatRNA and DNA are hydrolized by the pancreatic enzymes (ribonucleases, deoxyribonucleases) into nucleic acids, which are further broken down to purine and pyrimidine bases and pentoses, by enzymes in the intestinal mucosa (nucleases)
- 115intracellular enzymes-also called endoenzymes
-function inside cell
-responsible for synthesis of new cell components and extraction of energy - 116extracellular enzymesexoenzymes
-made inside cell but function outside of cell
-specifically; hydrolytic exoenzymes function to use water to break useful high molecular weight compounds into smaller bits that can be transported into cell - 117intracellular enzyme tests vs extracellular enzyme tests
- 118bacilli vs cocci cellular shapecocci is spherical shaped (most are anaerobic and cause infections in animals and plants)
bacilli is rod-shaped (tend to be gram + bacteria) - 119function of bacteria is often predicated ontheir shape
(correlated) - 120staph vs step cellular shape-staph = grape-like clusters; divide in various directions
step are gram + cocci that grow in pairs or chains - 121various cellular shapes (image)
- 122bacterial cellsingle bacterium or group of individual cells
(can be rod-shaped=bacilli, circular=cocci, or other shapes) - 123when referring to a single bacteriumbacillus
coccus
vibroid - 124when referring to arrangement of multiple bacterial cellsdiplobacilli
diplococci
staphylococci - 125basic schema of DNA extraction1) obtain a pure bacterial culture
2) cells are pelleted and resuspended in a buffer
3) cell lysis (using proteinase K and lysis buffer)
4) DNA purification and elution (adding elution buffer that will release DNA into a stable buffer and maintain integrity of DNA)
5) now can be used for PCR and Sanger sequencing - 126gel electrophoresisconfirming of PCR amplification of target gene
- smaller DNA fragments travel further down gel than large fragments
-molecular weight size maker (ladder) functions as a reference point to determine size (bp) of test sample
- 127e-valueestimate of background noise
-the lower the value, the more significant the match is
-how many hits one might "expect" to see when searching a database of a particular size - 128query coveragereport of what percentage of your query overlapped the given subject sequence
- 129percent identityalso called max identity
quantitative measurement of similarity between 2 sequences
-closely related species are expected to have higher % identity for a given sequence than would a most distantly related species
-reflects relatedness - 130frameshift mutationsgenetic mutation caused by detection or insertion in a DNA sequence that shifts the way the sequence is read
-result in abnormal protein products with an incorrect amino acid sequence that can be either longer or shorter than normal protein - 131general purpose of gene annotation and predictive modelinghelps us have insight of what these genes do in the body by establishing structural aspects and relating them to functions of different proteins/nucleotides
- 132—polymerase chain reaction
- 133number of cycles in PCR~35 to 40
- 134steps of PCR and their purpose1) denaturation step
- high heat facilitates denaturation of DNA; separates strands and opens up DNA pockets/expose nucleotides so we can add primers
2) annealing (lower temp will facilitate annealing of primers)
-primers will bind to complementary region of DNA that is typically flanking region we are amplifying
3) elongation (middle of low temp annealing and high temp denaturation)
-nucleotides will be added in piecemeal fashion by Taq polymerase (actively adding on dNTPs) - 135PCR mastermix1) 15.55 µl autoclaved diH2O
- fluid mastermix;universal solvent
2) 1.00 µl MgCl2
-facilitates efficacy of taq polymerase
3) 1.00 µl FWD primer
-defines region of genome to be amplified; binds/anneals to antisense/reverse strand of template DNA
4) 1.00 µl REV primer
- bonds to forward strand of template DNA
5) 2.50 µl dNTPs
-mix of deoxyribonucleotide triphosphates that polymerase will use to amplify target sequence (includes all four dNTPs)
6) 2.50 µl PCR buffer
-provides pH buffer for reaction to take place
7) 0.25 µl BSA (bovine serum albumin)
-keeps components in close proximity/prevents them from adhering to tube
8) 0.20 µl taq polymerase
-thermostable enzyme isolated from bacterium that will perform DNA synthesis/polymerization - 136once PCR mastermix has been homogenized,1.00 µl of extracted DNA will be added to 24 µl of Mastermix in PCR tube and ensure adequate homogenization by gently pipetting mixture up/down a few times
- 137—sanger sequencing
- 1382 gene browsing programsArtemis and BlastN
- 139chain terminating sequence is synonymous tosanger sequencing
- 140purpose of sanger sequencingfor sequencing regions that are roughly 1000 base pairs and below
- 141procedure of sanger sequencing1) PCR sequence DNA is combined with some dNTPs and ddNTPs
2) run gel electrophoresis with fluorescently-labeled ddNTPs
3) laser excitation and detection by sequencing mechanism --> chromatogram - 142sequence analysis steps
- 143BLASTn searches forNUCLEOTIDES
- 144DNA damages happens byUV
- 145UV damagescell viability by causing thymine dimers
- 146what are thymine dimerskink in DNA caused by UV
-2 adjacent thymine bases will change their binding proclivities to change from corresponding Adenine pairs to adjacent thymine - 147what is effected by thymine dimerstranscription, translation, formation of peptide and subsequent proteins, enzymatic activity
- impacts ability of organism to live/survive and thrive in environment
-can impede speed of DNA polymerase and its function by greatly increasing likelihood that it will misread the sequence at the point of dimer - 148with increased UV exposure -->decreased bacterial growth
- 149the greater the density of UV quanta and the longer the exposure duration -->the more dimers will be formed
- 150—DNA repair systems from UV light
- 151light/photoreactivation repairactivated when a cell is exposed to light within range of 420-540 nm
-activates a repair enzymes that will split any dimers that were formed - 152excision repairdoes not require light to activate it
-includes detection of DNA lesion (error), nicking of DNA strand containing error, removal of offending sequence (or nucleotide), and then writing of a patch using complementary DNA strand - 153gamma radiationionizing radiation
-things like x-rays and gamma rays - 154non-ionizing radiaitonencompasses everything from UV light, visible light, infrared light, and up to radio waves
- 155bacterial growth curve
- 156lag phase of bacterial growth curveinitial phase
bacteria are metabolically active but not dividing
increase in size but no cell division occurs in this phase - 157log/exponential phase of bacterial growth curvecells are dividing by binary fission and doubling in numbers after each generation time
-in this phase, antibiotics and disinfectants are most effectives as these substances typically target bacteria cell walls or protein synthesis processes of DNA transcription and RNA translation - 158stationary phase of bacterial growth curvegrowth reaches a plateau as number of dying cells equals number of dividing cells
-pop growth begins to decline as available nutrients become depleted and waste products start to accumulate - 159decline (death) phase of bacterial growth curveexponential decrease in # of living cells
nutrients become less available and waste products increase - 160alpha hemolysisrepresents partial decomposition of hemoglobin of RBCs
-greenish discoloration that surrounds bacterial colony
-hemoglobin to met-hemoglobin
- 161beta hemolysis-clearing of agar around colony
-complete breakdown of hemoglobin of RBCs in vicinity of bacterial colony
- 162gamma hemolysisno hemolysis at all
- 163alpha hemolysis is characteristic ofstreptococcus pneumonia
- 164beta hemolysis is characteristic ofstreptococcus pyogenes and some strains of S. aureus
- 165gamma hemolysis is characteristic ofEnterococcus faecalis
- 166parts of the microscope
- 167oil immersion is only used with100x objective lens
-oil has refractive index close to that of the slide
-when light shoots through diaphragm/stage/slide, less light is diffracted and more light can actually go through the specimen= can see specimen with tighter resolution - 168ocular lens4x mag
- 169objective lens10x, 40x, 100x
- 170total magnification =ocular lens x objective lens
- 171stage clipholds slide in place
- 172iris diaphragmcontrols amount of light emitted through stage and in through specimen
- 173illuminatorlight source
- 174coarse adjustment and fine adjustmentmove stage up and down
-coarse is only used under viewing conditions (after at 4x on objective lens everything should done with fine adjustement) - 175purpose of aseptic techniquefacilitates the growth and maintenance of pure cultures
-preserves integrity of those cultures for downstream analyses
-reductionist approach - 176asepsisabsence of bacteria, viruses, and other microorganism
- 177examples of asepsis1) flame-sterilizing inoculating loop
2) use of adductive vertical air currents (keeps dust particles and their microorganism from settling into plates)
3) alcohol to INHIBIT MICROBIAL GROWTH (WILL NOT COMPLETELY STERILIZE)
4) hand washing
5) limiting exposure of nutrient media (keep media capped and tubes of medium should be held at an angle)
6) ensuring workspace is clean/do not breathe on sample
7) storing and incubating solid medium plates inverted - 178microbes in the airmicrobes are omnipresent
if aseptic technique is neglected, then microbes in the air stand a greater chance of contaminating cultures - 179environmental sampling
- 180microbial growth is contingent onenzymatic activity, which is contingent on environmental conditions (pH, temp, osmotic pressure)
- 181osmotic pressure
- 182pH fluctuationsacidophiles (lactobacillus= yogurts)
neutrophile (mesophilic/body-physiological conditions)
- 183temp flucuations
- 184organism that thrives in fridgepyschrophiles
(listeria) - 185mode of function of ampicillininhibits bacterial cell wall synthesis
more effective on Gram (-) cells than penicillin - 186mode of function for penicillininhibits bacterial cell wall synthesis
binds to DD-transpeptidase - 187mode of function of vanomycininhibits bacterial cell wall synthesis
inhibits peptidoglycan crosslinking - 188mode of function of tetracyclineinhibits protein synthesis
binds to 30S ribosomal subunit
blocks peptide elongation - 189mode of function of chloramphenicolinhibits protein synthesis
binds to 50S ribosomal subunit
interrupts protein chain elongation - 190mode of function of streptomycininhibits protein synthesis
binds the 30S ribosomal subunit
induces codon misreads - 191mode of function of sulfonamidesslows folate synthesis by competitively inhibiting dihydropteroate synthase
- 192IMViC test seriesIdole, Methyl red, Vogues-Proskauer, in Citrate series
-purpose of further classifying coliform bacteria
-good at delineating members of Enterobacteriaceae (mesophilic, gram(-) bacilli that do not form endospores) - 193indole test-insight into what type of metabolism that microorganism engage in
-uses tryptophan enzyme (initial step of metabolism of this amino acid)
-uses Kovac's reagent
-positive result is cherry/rose color - 194indole test results (image)
- 195purpose of methyl red and voges proskauer testto determine which fermentation pathway is used to utilize glucose. In the mixed acid fermentation pathway, glucose is fermented and produces several organic acids (lactic, acetic, succinic, and formic acids)
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- Biology Flashcards on bacteriology lab final, created by madeline bertauski on 12/04/2021.
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- madeline bertauski · Apr 2021
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- Apr 19, 2021
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