Term
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Definition
Blue (daylight filter)
observation of unstained specimens |
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Term
| phase contrast microscopy |
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Definition
Green filter
Push slider far L or R at 100x
Push slide from opp unmarked end for 40 x |
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Term
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Definition
| pass smear slide thru hottest part of flame (blue), twice- cells then adhere to the slide |
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Term
| Microbial Eucarya include: |
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Definition
algae
protozoa
fungi
slime molds |
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Term
| Common shapes of Bacteria and Archaea |
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Definition
spherical
bacilli (rod shape)
spirilla (Spiral) |
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Term
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Definition
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Term
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Definition
Filamentous(molds)
unicellular (yeast) |
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Term
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Definition
unicellular or multicellular
wide variety of shapes |
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Term
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Definition
Psudomonas sp.
Bacillus sp.
Staphylococcus sp.
Enterococcus sp. |
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Term
| Types of Microbial Eukarya |
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Definition
Saccharomyces sp.
Penicillium sp. |
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Term
| Ocular micrometere Calibration |
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Definition
| use stage micrometer .01 mm- 10 um |
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Term
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Definition
number of stage micrometer divisions that corresponds to one ocular micrometer division
Measured in um/ocular unit |
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Term
Direct Cell Count (Hemacytometer):
1. Advantage
2, Disadvantage |
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Definition
1. the cells are actually observed and then counted
2. difficult to distinguish between viable and non-viable cells |
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Term
| When cells fall on a line during direct count you should: |
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Definition
Include those on the top and left hand lines
Exclue those on the bottom and right-hand lines |
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Term
| Connected chains and clusters in direct count technique is counted as: |
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Definition
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Term
| Units of Av. # cells per small square |
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Definition
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Term
| most bacterial dues are salts of two types: |
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Definition
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Term
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Definition
bear colored portion of the anion
was combined with a base, NaOh, form water solube salt. |
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Term
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Definition
bear chromophore on the cation
formed by combin. of color bearing compound w/ an acid like HCl form water soluble salt |
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Term
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Definition
Methylene blue
basic fuchsin
crystal violet
safranin |
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Term
| How do bacteria react toward stains? |
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Definition
| Cells act as if they bear a net negative charge, therefore a basic dye is used and binds firmly to the negative cell |
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Term
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Definition
| flood dried heat fixed smear w/ stain and allow to sit for ~ 1 min and rinse gently with water, observe. |
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Term
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Definition
| Colors the background but leaves the cells unstained and transparent, so they appear as light areas on a darkened field |
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Term
| What kind of dyes are used for Negative Stains |
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Definition
Acidic dyes like nigrosin or neutral dyes like india Pink since they do not readily stain the cells
Used commonly for Spirochetes |
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Term
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Definition
Stains that involve differences in cell wall composition:
Gram Stain and Acid-Fast Stain |
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Term
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Definition
Requires use of Four Reagents:
1.Crystal Violet (B.D.)- Stains the Org.
2.Iodine (Mordant)- Increases affinity between cell and the dye
3.Ethanol (D.A)- washes dye out of cell
4.Safranin (Counterstain) (B.D.)- gives the decolorized cells a contrasting color |
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Term
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Definition
| Cells retain initial dye (Crystal Violet) and appear purple |
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Term
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Definition
| Cells that decolorize readily and appear red after counterstain (pink) |
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Term
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Definition
| cells that are intermediate between the gram + and gram - stains. |
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Term
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Definition
| differential stain, used to distinguish between organisms that contain very large amounts of waxy lipid material (mycolic acids) |
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Term
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Definition
| Structural staining that is used to distinguish the presence of the bacterial endospore. Flood the smear with Malachite green dye, and then heat slide. New technology allows use of red carbol fuchsin and methylene blue |
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Term
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Definition
| reveals slimly layer that surrounds bacteria, capsule stains less readily then the rest of the cell. Combination of simple and negative stain used so the background is dark with the - stain, the capsule is clear and bright around the colored cells. |
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Term
| Who discovered Gram Staining and when? |
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Definition
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Term
| Gram + and Gram - Staining indicates: |
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Definition
| Cell wall type only for Bacteria |
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Term
| What is the Critical step in Gram Staining |
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Definition
Step Three:
Use 95% Ethanol, tilt slide gently and add drop by drop slowly for 20 s or until most of the dye has washed off the smear |
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Term
| Chemically defined (Synthetic) Media |
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Definition
| Prepared w/ precise chemical composition known. Used for enrichments [exercise 7] or in vitamin assay work. |
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Term
| Complex (non-synthetic) media |
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Definition
| Prepared where exact composition is NOT known, such as meat extracts, enzymatic digests of proteins, and yeast extracts. Support growth of wide variety of microorganisms. |
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Term
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Definition
Support growth of Chemoheterotrophs
Ex- Nutrient agar has beef extract, peptone and agar in water. |
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Term
| Fastidious Chemoheterotrophs |
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Definition
| must be cultured on general purpose media that has been enriched or supplemented with particular growth factors. |
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Term
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Definition
Contains reagents or chemicals that produce differences in growth and allow an observer to differentiate between types of microbes.
Ex- Blood agar medium, some bacterial colonies hemolyze the blood cells and produce clear areas in the agar. |
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Term
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Definition
Allow growth of only certain types of organisms due to addition of inhibitors or a specific carbon source.
"Survival of Fittest" |
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Term
| Ingredients commonly used in media |
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Definition
sodium chloride
hydrochloric acid
beef extract (amino acids, vitamins, minerals)
Peptone
Yeast Extract (AA, NA, GF) |
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Term
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Definition
complex carbohydrtae material of marine algae used ot produce semi-solid media!
Solidfies at 40-45 C and will not remelt until boiled.
Only some MARINE microbes use it as a nutrient material |
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Term
| Who invented the Enrichment Culture Technique |
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Definition
| 19th Century Beijernick (Holland) and Winogradsky (Paris) |
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Term
| What is the Enrichment Culture Technique |
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Definition
| allows isolation of almost any kind of organism using a liquid medium and providing suitable growth conditions |
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Term
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Definition
| Used liquid medium that contained nutients, good carbon source, energy source, most minerals, lacked nitrogen compounds. Used canal water, favored growth of organisms that utilized atmospheric nitrogen - NITROGEN FIXATION. |
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Term
| Common type Enrichment provides |
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Definition
| essential nutrients with one specific carbon and energy source (C/E) such as cellulose or petroleum hydrocarbons. |
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Term
| Experiment 7- Enrichment Culture Technique uses what type of media? |
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Definition
| General Purpose growth medium |
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Term
| What macronutrients are used in Ex 7 E.C.T. and the pH? |
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Definition
MgSO4
CaCl2
KH2PO4
K2HPO4
NH4NO3
FeCl3
pH of 7 |
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Term
| What was added to the media to reduce the growth of fungi and enhance the ability of recovering bacteria in Ex 7 ECT? |
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Definition
Cycloheximide (an antibiotic inhibits 80S ribosome function)
Nystatin (Antibiotic that inhibits function of fungal plasma membranes.) |
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Term
| Single Viable Cell deposited on Solid Agar Medium produces: |
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Definition
| Reproduces to form a cluster or colony of cells |
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Term
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Definition
| Constitutes a pure cultures, because it is considered to consist of similar cells all derived from the same original cell. |
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Term
| To make a detailed study of an organism this is needed: |
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Definition
| Isolated colonies can be obtained to produce PURE CULTURE |
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Term
| List two types of Selective Media used in Ex 8 of pure culture technique and selective media |
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Definition
Mannitol Salt Agar (MSA) - 10% Sodium Chloride as its key selective factor.
MacConkey Agar (MA)- Contains bile salts and crystal violet dyes as the key selective factor. |
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Term
|
Definition
bacteria can grow and ferment Mannitol
Form Yellow colonies
Those that can grow but CANNOT ferment mannitol form Red/Pink Colonies, |
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Term
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Definition
Bacter that can grow and ferment lactose form pink-dark red colonies
Those that can grow but CANNOT ferment Lactose form colorless colonies. |
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Term
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Definition
| small sub sample is inoculated into sterile petri plate and mixed with melted general purpose agar, it hardens and is incubated at app. Temperatures. During this each viable cell grows into a mass of cells and these masses appear as visible colonies |
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Term
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Definition
| used to prepare a plate in which all colonies appear on the surface (used w/ Aerobes) Created by inoculating the sub-sample onto the surface of a pre-poured, cooled plate |
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Term
| To ensure cell replication does not occur dilution blanks should be placed |
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Definition
| in chilled water baths before mixing the dilutions and agar together |
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Term
| How do you mix the contents of a pour plate? |
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Definition
| By rotating plate in a gentle figure-eight motion on the lab bench before the agar cools |
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Term
| What is added to a spread plate to assist in distribute the sample evenly? |
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Definition
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Term
| In the case of a sample containing spreading organisms this can be added |
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Definition
| sterile agar, small amount poured over the plate after it cools. |
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Term
| Instruments used for counting in Ex. 9 Enumerations of microorganisms |
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Definition
pen/ light box
Quebec Colony Counter |
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Term
| Only plates yielding___ to____ colonies are selected for counting |
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Definition
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Term
| Standard plate count is reported as |
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Definition
| the number of viable organisms or" Colony-Forming Units" per gm, or per mL of sample |
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Term
| Report plates with no colonies as |
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Definition
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Term
| Report plates with fewer than 30 colonies as |
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Definition
| Count teh actual number of colonies on teh lowest diluted plated, divide by appropriate dilution used and report as the pate count. |
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Term
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Definition
1. not uncommon, if more then half the surface of the plates is covered but no CFU/plate values, report as spreaders (Spr)
2. if covers over half report as greater then 300 colonies/plate.
3. laboratory accident- contamination, missed dilution |
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Term
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Definition
| yeast extract, peptone, glucose, casamino acids, soluble starch |
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Term
| Target Microbes for R2A medium |
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Definition
| Chemoheterotrophic Bacteria |
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Term
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Definition
| Yeast extract, peptone, lactose, bile salts, neutral red, crystal violet. |
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Term
| Target Microbes for VRBA medium |
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Definition
| Gram - enteric bacteria able to degrade lactose and withstand the presence of bile salts and dyes |
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Term
| What technique was used with R2A Agar |
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Definition
pour plate and spread plate
Cycloheximide was added to inhibit fungal growth |
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Term
| Spread plate technique was used in Ex 10 to distinguish |
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Definition
| morphotypes- descriptions for form, elevation, and margin, colony pigmentation and surface texture. |
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Term
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Definition
1. colonies with diff morphotypes are NOT the same type of bacteria
2. Colonies with the same morphotype may or may NOT be the same type of microbe. |
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Term
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Definition
| Used to indicate community structure and stability |
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Term
| Simple Diversity calculation |
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Definition
Species Richness- d
d- (S-1)/log N
S= # of species (colony types)
N- # of individuals (total # of colonies at a spec. dilution) |
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Term
|
Definition
Shannon-Weaver Index of Diversity (H)
H=(C/N) ((N LOG N -(SUM ni log ni))
C-2.3
N= # colonies
ni=# colonies/colony type |
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Term
| Highly selective Medium used in Ex 10 microbial enumeration |
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Definition
VRBA
due to the inhibitory bile salts and crystal violet dye, which will keep most non-enteric gram negative bacteria as well as gram positive bacteria from growing. |
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Term
| VRBA was used with food and water samples as a check on possible_______ ______ |
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Definition
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Term
| What technique is used for VRBA |
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Definition
| Pour plate due to fact that all enterics can grow in absence of oxygen and all coliforms can grow in presence of oxygen |
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Term
| R2A Agar samples incubated at |
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Definition
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Term
| VRBA agar was incubated at |
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Definition
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Term
| In R2A agar you counted ___ colonies |
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Definition
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|
Term
| In VRBA agar you counted only _____ colonies |
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Definition
| coliform (red/purple), Gram Negative enteric bacteria able to produce acid from lactose fermentation |
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Term
|
Definition
| punctiform, circular, filamentous, irregular, rhizoid, spindle |
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Term
|
Definition
| Flat, raised, convex, pulvinate, umbonate |
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Term
|
Definition
| Entire, Undulate, Lobate, Erose, Filamentous, Curled |
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Term
| Calibration factor for 10x |
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Definition
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Term
| Calibration factor for 40 x |
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Definition
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|
Term
| calibration factor for 100x |
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Definition
|
|
Term
|
Definition
| Gram - and looks like short fat rods |
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Term
|
Definition
| Gram + and clonies were small white and cocci |
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Term
| Colonies that appear yellow on MSA |
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Definition
can ferment mannitol
gram + Cocci |
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Term
| Colonies that appear red/pink on MSA |
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Definition
cannot ferment mannitol
Gram + Cocci |
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Term
| Colonies that appear pink- dark red on MA |
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Definition
can ferment lactose
Gram - Rods |
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Term
| Colonies that appear colorless on MA |
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Definition
Cannot ferment lactose
gram - rods |
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