BIO 2051 LSU Brininstool Lab final Vocab and such

Paul Erlich

-______________, a german doctor who dreamed about finding a chemical that would cure all diseases, in the late 1800s he began experimenting with ______________________, which are chemical substances used in living bodies for treatment

-in 1928, a birtish physician ______________ was working with staphylococci in a londom hospital noticed a plate he was growing was not growing near a mold that had formed, he identified the mold as penicillin

antibiosis

-Fleming had observed ____________, which is the symbiotic relationship between two organisms in which there is inhibition, injury or killing of one organism by another.

Antimicrobial agents

Cidal agents

Lytic agents

Static agents

-kill or inhibit the growth of microorganisms

-are lethal to microorganisms, bacteriocidal agents kill bacteria, virucides destroy viruses, and fungicides kill fungi

-are cidal agents that lyse or break open cells

-only inhibit the growth of microorganisms. Bacterio and fungistatic also exists, though they dont directly kill microbes by inhibiting growth, they givethe immune system, physical mechanisms and chemicals time to drive the microbes out

disinfectants

decontamination

-are antimicrobial agents for use on inanimate surfaces like bench tops, most are too harsh to apply to living tissue, ammonia ethanol and bleach are examples

-the use of disinfectants to eliminate or reduce the number of microorganisms on surfaces can be called ______________

environmental surveillance

it is necessary to determine the most effective approaches to decontamination, monitoring the organisms present and the effect of decontamination is called ___________________

antiseptics

are antimicrobial agents that can be applied to skin but are not safe or ingestion, ethanol and iodine are examples

antibiotics

-are antimicrobial chemotherapeutic agents of microbial origin, often taken orally or given intravenously, used to kill or inhibit the growth of bacteria, penicillin and streptomycin are examples

susceptible

resistant

-several factors must be considered to evaluate the effectiveness of antimicrobial agents, for ex. concentration, some microbes are ______________ to a low concentration of the agent, whereas high concentrations of the agent might be needed for other microbes, time is also a factor some need longer exposure time or shorter

-dormant forms such as endospores, and thick layers like biofilms are very _______ to the action of chemical agents and can survive high concentrations or long exposure

mode of action

Penicillin

Streptomycin

-clinical microbiologists and physicians must be aware of the __________ of different antimicrobial chemotherapeutic agents, this is the way the agent kills or inhibits growth

-prevents insertion of new peptidoglycan into an expanding cell wall, weakening cell wall and making it susceptible to lysis, gram positive cells are weak to it

-is aminoglycoside that prevents protein synthesis by binding to the 16s rRNA in small 30s subunit of bacterial ribosome, interfering with binding of formyl-methionine tRNA to 30s subunit

pathogen

disc diffusion method

zone of inhibition

-a microbiologists like a med tech working in a hospital or medical clinic needs to identify and isolate the ___________, then provide the physician or vet the information necessary to treat the disease

disc diffusion method

zone of inhibition

minimum inhibitory concentration

-the ____________________ such as the Kirby-Bauer method, filter paper disks saturated with specific concentrations or antimicrobial drugs are placed on the surface of agar plates that have been heavily inoculated with the disease causing isolates, the pathogen should grow on the entire surface unless it is inhibited from growing in the presence of the drug

-if this happens then a ________________ will appear as a clear area which there is no bacterial growth around the disk

-the amount of drug at the edge of the zone of inhibition is the _________________________

enzymes

-Metabolism is the sum of the reactions that are associated with the life of the cell, all of the reactions are catalyzed by ________, proteins that serve as biological catalysts. Without them none of the reactions associated with a living cell would occur at a rapid enough pase

extracellular enzymes

-are enzymes that act outside the cell in which they are produced, they degrade large molecules into unites that are small enough to be transported by proteins across the cell membrane into the cell where they can be used.

Endoenzymes

-act inside the cell to synthesize the molecules that are needed by the cell or degrade molecules to simpler molecules. ex catalase and oxidase which are associated with aerobic respiration

inducible or adaptive

disaccharide lactose

-as energy conserving mechanism, some enzymes are produced only if the appropriate substrate is available, these are called_________ or _______ enzymes ex. B-galactosidase which is used to break down ____________ into glucose and galactose

constitutive

-enzymes that are always in need by the call and produced at all times are __________________. ex catalase and oxidase

morphology

physiology

-microbiologists study different features of microorganisms to identify them. to examine cell size, shape, arrangement is to study its ____________________

-microbiologists also study an organisms metabolic capabilities, which includes its enzymes and how it reacts biochemically, this tells how the organism functions in an environment and is the study of its _______________

aerobic respiration

-oxidase and catalase enzymes are made by organisms that produce energy using ________________, during this membrane electron transport chain components cycle between the oxidized and reduced state as they donate and accept electrons, this releases protons outside the membrane allowing to build H+ gradient that leads to ATP production

cytochrome oxidase

-in aerobic respiration molecular oxygen serves as the last electron acceptor. To be reduced oxygen accepts an electron from a protein in the electron transport chain called _________________.

cytochrome c oxidase

neisseria and moraxella

Acinetobacter

Pseudomonas and Vibrio

Escherichia and Enterobacter

- an oxidase assay tests for the presence of ______________________.which is present in oxidase positive organisms

It is mostly used to differentiate the genera between

-oxidase positive ?

-oxidase negative ?

and

-oxidase positive ?

-oxidase negative ?

Superoxide

Hydrogen Peroxide

Hydroxyl radical

-when oxygen is reduced at the end of the ETC in aerobically respiring cells, byproducts such as ____, _____, _____ are produced which are toxic to cells, organisms have enzymes to detoxify these byproducts.

Staphylococcus and Micrococcus

Streptococcus and Lactococcus

catalase is produced by essentially all microorganisms that use oxygen for respiration such as species of _______________ and _______________.

Generally bacteria that dont utilize oxygen for respiration dont produce catalase, such as species of ____________ and ______________

catalase

bubbles

-the enzyme _______ breaks hydrogen peroxide into water and molecular oxygen, the oxygen produced can be observed due to production of _________, it is produced by basically all microorganisms that use oxygen for respiration

tetramethyl-p-phenylenediamine dihydrochloride

oxygen

bright blue/purple

-the reagent __________________________________ can be used to test an organisms ability to produce cytochrome c oxidase, this can be directly added to bacteria grown on a plate, it serves as an artificial substrate to be oxidized by cytochrome c oxidase in the presence of ________

-if cytochrome c oxidase is present the reagent will turn_________

dark dier

acetate

-______________ mutants of Chlamydomonas reinhardtii have mutations in the mitochondrial gene coding for cytochrome oxidase.

C. reinhardtii is a photosynthetic green algae capable of oxygenic photosynthesis in the light but if no light is present it can use an electron source such as _______ to do it regardless

cytochrome oxidase

HSA

HA

-C. reinhardtii requires a functional___________________ for aerobic respiration when grown in the dark on acetate.

-___ high salt medium plus plus acetate provides acetate for the cell

-Minimal growth medium _____ lacks an electron source for respiration so it must be grown in light to allow for photosynthesis

catalase assay

-may be used to distinguish between different genera of bacteria, organisms that due aerobic respiration produce catalase while organisms that are strictly fermentation don't

divide slide into thirds and have a + control, sample A-H, and -control, add a drop of hydrogen peroxide to each third, transfer cells of Staphylococcus epidermidis to - side, then add Streptococcus mutans to + side, then add sample in middle

-if there is a production of bubbles it means they are catalase positive and none would be negative.

How does a catalase assay work

What would the findings say?

divide TSA plate into thirds, having a +control, A-H, and - control. Inoculate + with Pseudomonas putida in a line, inoculate - side with E. coli and the sample with A-H, incubate, when following up transfer 200 ul of oxidase reagent to each line

-will turn blue/purple where reagent was added ex. Psuedomonas putida

-little to no change ex. E. coli.

How to perform an oxidase assay

what would findings say?

-positive result

-negative

-both WT and dk grow because light allows photosynthesis and acetate is also present

-both WT and dk grow, photosynthesis supplies carbon/energy, photosynthesis bypasses mutants defect

-WT grows because it can use acetate but dk cant grow because it cant use acetate in dark

-neither grow because no light and no acetate = no energy source, without light acetate is necessary for growth

effects of mutation on oxidase function of WT and dark dier

-Light / HSA

-Light / HS

-Dark / HSA

-Dark / HS

anaerobic respiration

-an energy efficient metabolism in the absence of free oxygen, these organisms may utilize SO42-(sulfate), CO32-(carbonate), or NO3-(nitrate)as a terminal electron acceptor for respiratory electron transport chain

Denitrification or nitrate reduction

ammonia

-some soil microorganisms use nitrate in the soil to process hydrogen produced in respiration, ____________ or _______________ is the series of reactions that reduce nitrate to dinitrogen gas, some prokaryotes are capable of further reduction of nitrogen into ____________

Durham tubes

N2O and N2

-the ability of microorganisms to reduce nitrate will be examined by inoculating tubes of nitrate brother containing __________________ to demonstrate gas production

-a gas bubble will be visible in the tube if _____ and ___ were produced from nitrate reduction

Paracoccus denitrificans

Escherichia coli

Bacillus magaterium

Organisms used in testing nitrate reduction

Pd?

Ec?

Bm?

a negative

and sample A-H

the tubes inoculated should show growth if they can use nitrate.

no

-after testing for use of nitrate you should see what in tubes that can use it?

-the negative control tube should have _____ growth

smell if there is a stale urine odor of ammonia

How to test for the reduction into ammonia NH3?

there are gas bubbles in Durham tube

how to test if there was a reduction to dinitrogen gas N2 and nitrous oxide N2O?

look for red color after full dropped of a-naphthylamine acetate + sulfanic acid was added

how to test for a reduction to nitrite NO2-?

add Zn2+ to the tubes which there were no bubbles or color change after adding a-naphthylamine acetate + sulfanilic acid

NO2-

NO3-

-how to test for unused NO3- (indication organisms did not reduce nitrate)?

-if NO3- is still present (meaning bacteria did no reduce it) the Zink will react with No3- and reduce it to _____ which will combine with the reagents and the red color will appear within a minute.

-if even then no color was seen, this means there was no NO3- remaining. products of reaction could not be determined

autotropic

autotrophs

heterotrophic

-organisms obtain carbon from the CO2 in the air

-fix the carbon from the CO2 into methane, acetate, sugars and other carbon compounds depending on metabolic ability

-cells that require an organic carbon containing compound other than CO2 as the source are called ________________

phototrophs

chemotrophs

chemoorganotroph

chemolithotroph

-use light as energy source

-use chemicals as energy source

-chemotrophs uses organic compounds as energy source it is ______________

-if chemotroph uses an inorganic compound as energy source is it called __________________

biosynthesis

catabolism

glycolysis

-microorganisms catabolize or break down large molecules to obtain energy and smaller carbon-containing compounds for ________.

-____________ can use fermentation for respiration

-__________ is the process buy which glucose is converted to pyruvic acid, is common for both fermentation and respiration.

phenol red

orange/red

bright yellow

bright pink

-the ability to ferment a carb can be determined if a single carb is added to a nutrient broth containing non-fermentable nutrients to support growth and a pH indicator

-______________ is used in this lab as a pH indicator

-around neutral pH the broths have a ___________ appearance. microbial fermentation products such as alc help maintain a neutral pH

-if pH drops below 6.8, the phenol red becomes ____________, various acids can drop pH

-above pH 8.2, phenol red turns __________

Saccharomyces cerevisiae

turbidity

Carbon dioxide

fermentation

decreases

to test fermentation of saccharomyces what is scraped into the tubes of either malt extract or grape juice?

What would growth be indicated by?

-if the durham tube is filled what gas waste product was produced

-musty wine or beer odor indicates

-Carbon dioxide produced by Sacchromyces during fermentation ______________ the pH of the broths

glucose, lactose, sucrose, mannitol

-Uninoculated control

-acid and gas produced from fermentation

-acid but no gas produced

-alkaline reaction

-growth but no acid (negative)

Testing for fermentation by bacteria

-start with 4 phenol red tubes with what 4 things?

Incubate each with small scraping of A-H and after what do these findings mean

-orange/red

-yellow with gas

-yellow no gas

-bright pink no gas

-orange/red cloudy no gas

amylases

proteases

-are used commercially to produce glucose and syrup from starch and to remove coatings in the paper and textile industry

-__________ such as collagenase are used in the treatment of burns and wounds and chymosin, a caseinase, is used in cheese making

-carbohydrates

-are compounds that compose of carbon, hydrogen, and oxygen in a 1:2:1 ratio.

monosaccharides

Oligosaccharides

Polysaccharides

-small carbohydrates are, ______________ which are single sugars, usually with 5 or 6 carbons

-which means few sigars are composed of two or more monosaccharides

-are larger polymers of monosaccharides and may serve as structural components or as impoartnt reserve carbon and energy sources

iodine

clear area or zone of hydrolysis

-the addition of _____ to a plated medium makes starch that was not broken down evident because it reacts together to produce a brown color, E. coli grown on that plate would be brown because it does not produce amylase

-a _______________will be evident around a amylase producing colony after the plate is flooded with iodine, this is caused by hydrolysis of the starch by amylase

proteins

peptide bonds

proteases

peptides

-are macromolecules composed of one or more polypeptides, long chains of amino acids joined covalently by, ______________

-nutrient proteins may be too large to be transported into a bacterial cell. They must first be hydrolyzed by __________ into shorter chains of amino acids called _______, which must be degraded into individual amino acids before the cell can use them

proteases

-many fungi and some bacteria produce extracellular ________, these play an essential role in degrading dead animal and plant tissues in the environment. some are used in detergent and stain removers.

Casein

caseinase

-is one of the proteins present in milk, is a very large protein that is colloidally suspended in milk and gives milk is opaque appearance and white color

-the addition of sterile skim milk to nutrient agar provides a good medium to grow microorganisms and demonstrate the production of _____________ which will cause clearing, if organisms cant produce this then there will be no clearing

gelatin

hydrochloric acid HCl

gelatinase

-___________is a protein extracted from the connective tissue and bones of animals will solidify below 26 but liquid above 28 C. so not useful for human pathogens

-the addition of__________________ to a plate will result in the precipitation of the gelatin in the agar making the agar look opaque

-organisms that can produce __________ will have a clear, transparent area there due to the hydrolysis of gelatin.

1 N hydrochloric acid HCl

opaque

gelatinase

-what do you flood GA plate with to test for remaining gelatin in agar?

-if it is present the agar should become _________ after a few minutes, usually where no bacteria is present and for negative control

-________ production will be evident by a clear area around and under these producing organisms like B. subtilis, this area is caused by proteolytic cleavage of the protein gelatin.

carboxylic acid

amino

There are twenty amino acids commonly found in living cells. All of them have two important functional groups, a ___________________ group and an ______ group, attached to the alpha carbon

cysteine

cysteine desulfhydrase

-contains a sulfhydryl group (-SH) that plays as essential role in protein structure by connecting amino acid chains through disulfide linkages.

-cleavage of sulfhydryl group is the first step of metabolic breakdown. this reaction is catalyzed by ________________________, this results in the release of hydrogen sulfide gas which smells like rotten eggs.

peptone iron agar

peptone

ferric citrate

Extremely soluble in water, hydrogen sulfide has cannot be trapped in a Durham tube so a ____________________ is prepared as agar deep to demonstrate the production of hydrogen sulfide

this medium contains two things

-a digest of animals proteins rich in cysteine

-is an indicator that reacts with hydrogen sulfide to form ferrous sulfide FeS, a black insoluble precipitate.

Citrobacter freundii

black

H2S

-_______________ is the organism used to test cysteine desulfhydrase production.

-after incubation the presence of a _______ precipitate indicates that cysteine desulfhydrase was produced by the organism and caused the release of ______ which reacts with the iron citrate agar to produce the percipitate FeS

Gram positive, catalase-negative cocci

pathogenic

strep throat, scarlet fever, pneumonia

meningitis

impetigo

-many species of the genus Streptococcus, which are _________________________, usually in chains, are present in the normal microbiota of healthy humans. these can be found in mouth and intestines in the mucus membrane

-several species of streptococci can cause serious illness and are considered _______, along with what other illnesses _____, _____, _____ and also _________ (infection of lining of brain and spinal column), and a skin infecion called _______

fastidious

blood agar

-some streptococci, especially the pathogens, are __________ organisms that require enriched media and a controlled atmosphere in order to grow

-______________, a nutritious differential medium which 5% sterile sheep blood has been added after the sterile medium has been tempered is great it growing streptococci

Hemolysin

nonhemolytic

-blood agar is especially useful for streptococci because is demonstrates _________production, these are proteins that damage animal cells and can cause them to lyse

-organisms that don't produce this can still grow on blood agar and are called ________________

Alpha or a-hemolysis

methemoglobin

-______________ is an incomplete lysis of red blood cells and is seen as partial clearing of the red cells and a grey-greenish darkening of the agar around the colony of this bacteria

-this greening is due to the production of __________ from hemoglobin, the iron containing molecule in red blood cells which carries oxygen

Hemolysis

when isolating streptococci, after incubation examine the blood agar plate from your throat culture as well as the sample plates showing examples of alpha, beta, and gamma hemolysis,

-_____________ can be determined only for isolated colonies.

positive

When testing for lactobacilli and tooth decay, after incubation a change from green to yellow such that green is no longer dominant is a _________ test.

viridans

-many of the species of streptococci that are normally present in the mouth and upper respiratory tract of humans like streptococcus mutans and Streptococcus sanguinis are a-hemolytic and are referred to as ____________ streptococci.

Beta or B Hemolysin

-Streptococcus pyogenes, the pathogen which causes strep throat, scarlet fever, and several other serious illnesses, produces _____________, which causes the complete destruction of the red blood cell and is seen as a clearing around a _______________ colony on blood agar.

Virulence factors

-are structures or substances produced by a microorganism which enhance its ability to cause disease. Bacterial capsules and enzymes such as coagulase or hemolysin are examples of it.

streptokinase

-the enzyme, _________ is another virulence factor produced by pathogenic streptococci. It dissolves fibrin clots, which could enhance the organisms ability to invade tissue and cause disease to spread. These if purified can also be used to therapeutically dissolve blood clots

Streptococcus pneumoniae

-_____________________ is a facultative aerobe, growing weather oxygen is present or absent

-__________________ is microaerophilic and prefers increased CO2 and reduced oxygen tension

-other species are ___________, which can only grow in the absence of oxygen

Dextran

dental plaque

-_____________ is a gummy substance that coats teeth and helps hold bacteria in place, an accumulation of this and bacteria is a biofilm called _______________.

Lactobacillus

-Streptococci and organisms of the genus _________________ metabolize sugars to produce lactic acid, which will remain trapped in the dextran bacterial cell matrix

Snyder's test agar

Bromocresol green

dextrose

-is used to indicate the relative number of lactobacilli in saliva. The pH of this medium is 4.8, which inhibits the growth of most bacteria

-________________ served as the pH indicator in the medium giving it a blue green color at pH 4.8.

-If Lactobacilli is present, they willl grow at this low pH and ferment the _______ in the medium into lactic acid

flora

Gram-positive, catalase-positive cocci

-species of the genus Staphylococcus are part of the normal microbiota or ______ of the human skin as well as the mucus membrane of the nose and throat

-Staphylococcus aureus are ______________, ___________________________, that occur in clusters, it can cause sever illnesses especially in patients who are hospitalized.

pathogen

gastroenteritis

staphylococcal food poisoning

coagulase

-S. aureus may produce many virulence factors and is considered a _________ or disease causing bacterium

-S. aureus also produces a superantigen enterotoxin which is responsible for severe ____________ or ___________________________. another one is Toxic Shock syndrome

-the enzyme________ causes plasma to clot and is produced by S. aureus as well

Staphylococci are responsible for a high number of nosocomial infections, which can be life threatening

mannitol salt agar MSA

-was developed for isolating Staphylococci from food samples, it contains 7.5% NaCl, an elevated concentration that inhibits the growth of many microorganisms and makes it selective for those that tolerate it

-MSA is also a differential medium by containing the fermentable carbohydrate ______________

Plasma

-Microbiologists look for the production of a suspected isolate as S. aureus by inoculating a small tube of _________ which is is the liquid protein of anticoagulated blood and contains the clotting factor

fibrinogen

-one clotting factor is _______________, which is present in plasma as a soluble protein, Coagulase causes it to break into short strands of fibrin, which interact to form a fibrin clot

lichen

-an example of mutualism is __________ which is formed by heterotrophic fungus and photosynthetic alga or cyanobacterium. It can exist in places where neither fungus or alga can exist alone.

commensialism

-the human harbors obligate anaerobes like members of genus bacteroides that require absence of oxygen, Facultative organisms such as E. coli can remove oxygen via aerobic respiration, giving obligate anaerobes an oxygen free environment, this is called ___________________.

Clostridium sporogenes

Staphylococcus epidermidis

thioglycollate

in this lab you will see a commensalistic relationship between

-an obligate anaerobe

-a facultative anaerobe

-to grow C. sporenges it must be grown in an oxygen free medium such as ___________ broth in a sealed flask, which reduces any oxygen present

Potable water

enteric diseases

-water that is safe to drink is called_____________

-many ________________ (those that effect gastrointestinal tract) are transmitted from infected individuals to others by fecally contaminated water. This is common in underdeveloped countries.

coliforms

-environmental and water quality microbiologists look for the presence of _______, which are aerobic or facilitatively anaerobic Gram-negative non-spore forming rods that produce gas from lactose within 48 hours of incubation at 35 C.

An example of this is E. coli which is found in large numbers in sewage and is used as the indicator organism for fecal contamination

Klebsiella aerogenes

-may be found in feces but may also be present in the environment and in decaying vegetation which has not been contaminated with feces.

total coliform count

most potable number technique (MPN)

presumptive, confirmed, completed

is used to indicate sewage pollution

-the total coliform count can be indexed by a statistical estimate known as the _____________________________ which relies on the characteristic of gas proception from lactose, which is common to coliforms.

-this technique is a series of three tests, _____________, _______________, ______________.

lauryl sulfate lactose broth LSL

Lauryl sulfate

coliforms

fermentation

lactose

Presumptive Test

-dilutions of the water being sampled are added to tubes of __________________________ with durham tubes and incubated for 48 hours.

-________________ selects for intestinal bacteria by inhibiting the growth of other organisms and lactose is a differential component.

-___________ ferment lactose to produce CO2 gas, which is observed by bubbles in tubes.

-________________is a metabolic process used in the production of cellular energy

-in the MPN test we use the fact that coliforms can ferment ________ and produce CO2, then the MPN index for water sample can be determined.

brilliant green lactose bile BGLB broth

non-coliforms

positive confirmed

Confirmed Test

-a loopful of BGLB broth from a tube showing gas production must be streaked for isolation onto an _________________ plate to complete the test for coliforms.

-this medium employs that dye and bile to inhibit ___________ from growing.

-Lactose fermentation results in gas formation in the Durham tube constituting a__________ test.

eosin methylene blue EMB agar

gram positive

gram negative

drop

pale or colorless

Completed Test

-a loopful of BGLB broth from a tube showing gas production must be streaked for isolation onto an ________________________ plate to complete the test for coliforms.

-EMB agar contains the dyes that inhibit the growth of ________________ and select for __________________ organisms.

-on EMB agar lactose fermentation causes a _____ in pH around and under the colony, resulting in uptake of dyes by the colonies of lactose fermenters.

-non lactose fermenters produce ________________ colonies on EMB agar

drop

pale or colorless

coliforms

darkened

green

Klebsiella aerogenes

fish eye colony

-on EMB agar lactose fermentation causes a _____ in pH around and under the colony, resulting in uptake of dyes by the colonies of lactose fermenters.

-non lactose fermenters produce ________________ colonies on EMB agar

-_____________ which are gram negative lactose fermenters, grow well on EMB agar and produce __________ colonies ex E. coli will produce a dark almost black colonies with a _______ metallic sheen on its surface

-_________________ is a coliform closely related to E. coli but produces much less acid, only the center of the colony uptakes dyes and the outer edges are pink, this is called a __________________

inoculate another BGLB broth and a slant from one colony on EMB agar.

gas

gram stain

rods

-if colonies that have the appearance of typical coliforms develop on EMB plate, the final step of the MPN series are to do what?

-____ must develop within 24 hours in the broth and a __________ from the slant bust show a pure culture of gram negative ______ to complete the test for coliforms

2.2

-in the US the environmental protection agency sets a standard for drinking water, water is potable if it contains less than _____ coliforms per 100 ml of water as detected in MPN technique

IMViC

represents the order and names of 4 tests used to distinguish coliforms from each other as they can seem similar

tryptophanase

Indole test

-some organisms produce the enzyme _________________, which breaks down the amino acid tryptophan to indole, pyruvic acid, and ammonia.

indole

Kovacs reagent

red

colorless or pale orange

-tryptophanase production by which an organism is determined by testing for the production of _______ in 1% tryptone broth

-following inoculation and incubation ______________ is added to the tube of tryptone broth, it will combine with the indole to form the _____ layer that floats on the broth

-if tryptophanase was not produced, a ___________ or ______ _______ band will appear at the top of the liquid in the tube

glucose

drop

red

yellow

4.2

Methyl red and Voges-Proskauer tests

-_________ is fermented by all coliforms, some organisms such as E. coli utilize mixed acid fermentation and produce many molecules of succinic, formic and lactic acids from this.

-Mixed acid fermentation results in a significant _____ in pH which is detected in the methyl red test, after methyl red is added to a tube of MRVP broth which contains glucose a ______ color indicates a positive test, this indicator is _______ at neutral pHs and does not turn red until pH drops below ____.

-

mixed acid fermentation

-glucose is fermented by all coliforms. some organisms like E. coli use _________________ which results in a drop of pH which can be detected in the methyl red test. this also produces many molecules of succinic, formic, and lactic acids from glucose.

butanediol fermentation

acetyl methyl carbinol

-some coliforms such as K. aerogenes, employ __________________ and produce much less acid from glucose, these organisms give a negative methyl red test because they produce more neutral fermentation products

-production of one of these neutral products, _______________________ (or acetone) is assessed in the Voges-Proskauer test

alpha naphthol and 40% potassium hydroxide

Voges-Proskauer test

-following inoculation and incubation, __________________ and __________________________ are added to a portion of the MRVP broth, these reagents will react with acetyl methyl carbinol and oxygen to produce a wine _____ color seen best at the top of the broth where the oxygen is

Simmons citrate agar

bromothymol blue

blue

-is the medium used to determine weather an organism can utilize citrate as its sole carbon source. some coliforms don't produce the enzyme that transports citrate into the cell and cant grow on this medium

-The pH indicator _____________________, is a green color at neutrality, but organisms that produce the citrate transport enzyme grow well on Simmons citrate agar slats will turn the green color to a deep ______ due to the rise in pH as the organism grows and alkaline products are formed.

nitrogen and carbon

-____________ and ____________ are two macromolecules required by all organisms for use in building of biological molecules such as nucleic acids, proteins, and phospholipids. they can be obtained by the air or organic molecules.