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61 Cards in this Set
- Front
- Back
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routinely used in preparing and maintaining stock cultures as well as for microbial test procedures. |
culture techniques |
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how microorganisms are transferred from one medium to another |
subculturing |
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method involving target specific practices and procedures which aims to avoid contamination of microbes under controlled conditions like in laboratories |
aseptic technique |
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a liquid medium |
broth |
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tube of solid medium at an angle |
slant |
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tube of solid or semi-solid medium |
agar butt |
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differential staining technique used to classify bacteria based on their cell wall composition |
gram staining |
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four basic steps of gram staining |
applying primary stain (crystal violet) addition of mordant (Gram’s iodine) rapid decolorization by alcohol counterstaining (Safranin O) |
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microorganisms that retain the primary dye |
gram-positive |
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microorganisms that take the color of the counterstain |
gram-negative |
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Example of gram-positive bacteria |
Streptococcus, Staphylococcus, Bacillus, Listeria, Clostridium |
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Example of gram-negative bacteria |
E. coli, Salmonella, Chlamydia |
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Step 1: crystal violet |
-primary stain added to the specimen smear Effects: stains cells purple or blue |
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Step 2: iodine |
-makes the dye less soluble so it adheres to cell walls Effect: cells remain purple or blue |
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step 3: alcohol |
-decolorizer, washes away stay from gram-negative cell walls Effect: gram-positive remain purple or blue, gram-negative are colorless |
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step 4: Safranin O |
-counterstain allows dye adherence to gram-negative cells effects: gram-positive remain purple or blue, gram-negative appear pink or red |
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certain gram-positive bacteria such as Clostridium and Bacillus from specialized “resting cells” called |
endospores |
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highly durable dehydrated cells with thick walls and additional layers |
endospores |
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steps in endospore staining |
primary stain (malachite green) safranin (counterstain) |
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after endospore staining, vegetative cells will be: endospores will be: |
vegetative cells will be: pink endospores will be: dark green |
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round cells, sometimes slightly flattened when they are adjacent to one another |
cocci |
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the cocci are arranged in pairs |
diplococci |
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the cocci are arranged in chains |
streptococci |
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the cocci are arranged in cuboidal manner |
sarcinae |
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the cocci are arranged in grape-like structures |
staphylococci |
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rod-shaped bacteria |
bacilli |
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intermediate between coccus and bacillus |
coccobacillus |
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bacilli that appear in pairs |
diplobacilli |
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the bacilli are arranged in chains |
streptobacilli |
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the bacilli bend at the points of division, arrangement of angular patterns |
palisades |
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curved shaped to a corkscrew-like spiral bacteria |
spirillum |
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curved rod shape or comma shaped bacteria |
vibrio |
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helical and flexible body |
spirochetes |
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star shaped bacteria |
stella |
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rectangular bacteria |
Haloarcula spp |
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Box shaped bacteria |
Haloquadratum |
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bacteria that does not have any characteristics shape. They can change their shape |
Pleomorphic bacteria |
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Filamentous Bacteria |
Thiothrix |
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long and thread-like and connected end-to-end |
hyphae |
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refers to the whole body of a fungal organism |
mycelium |
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growing portion of the fungus that specialized for the release of spores |
sporocarp |
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cell walls of fungi are made of |
chitin |
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formed within a sporangium or sac at the end of the aerial hyphae |
sporangiophores |
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spore that are not enclosed in a sac, produced in a chain |
conidiospores |
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thick walled spore formed by rounding and enlargement within a hyphal segment |
chlamydiospore |
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study of fungi |
mycology |
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lower fungi (ex. Rhizopus) |
Zygomycetes |
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ascospores in sac (ex. Truffles and morels |
Ascomycetes |
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club fungi (ex. mushrooms) |
Basidiomycetes |
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lack sexual spores (ex. Penicillium) |
Deuteromycetes |
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identification of fungi macroscopic features |
colony characteristics, growth rate, color, texture |
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Identification of fungi microscopic features |
arrangement if spores and sporing bodies |
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Methods to examine fungal morphology |
Tease of fresh mount: teased with needles Slide-culture: grown directly on the slide |
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referred to as the standard plate count that indicates the level of microorganisms in a product |
Aerobic Plate Count (APC) |
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Limitations of APC |
Bacterial species are not identified Prone to human error Contamination may alter results Only viable aerobic organisms are counted |
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Standard Methods of APC |
Sample preparation > Serial Dilution > Plating > Plate Count |
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process by which the original inoculum is diluted in dilution tubes in a way that the concentration of the cells in the tube is only one-tenth of the preceding one |
Serial Dilution |
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microorganisms are spread over to the surface of an agar plate resulting in the formation of discrete colonies on the agar surface |
spread plate technique |
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microorganisms are added to molten agar medium prior to its solidification. Colonies are uniformly distributed throughout the solid medium |
pour plate technique |
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Countable colonies : 25-250 <25 : TFTC >250 : TNTF |
True |
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hidiej |
hsjsidi |
