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109 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What are the 6 chemical factors?
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1. Water 2. Trace Elements, 3. Nitrogen Sulfur and Phosphorous 4.Growth Factors
5. Carbon and Energy 6. Oxygen |
W.T.N.S.P.G.C.E.O = what the nitrogen sulfur phosphorous Gloria Can Everyone Own?
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What is the significance of water?
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1. Used to dissolve nutrients and many soluble enzymes
2. Important reactant in many metabolic reactions |
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What type of water is best for bacterial growth medium and why?
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Tap water because it contains sufficient trace elements
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What bacteria, mentioned in lecture, can survive for months in dry conditions?
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Mycobacterium tuberculosis can survive because the cell wall retains water.
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What other molecules can survive without water?
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Spores and cysts of Protozoa because they are in a suspended state and neither grow or reproduce
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Trace elements are also know as?
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Micro nutrients
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List 6 trace elements mentioned in lecture?
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Copper, Zinc, Se, Mg, Mn, Fe2+
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What is the importance of Fe2+
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Iron is used in ATP production. It is a part of the ETC. Bacteria is always trying to scavenge for Iron.
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Where is Iron stored in the human body?
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Liver (ferritin) Blood (transferrin)
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What is the importance of Nitrogen?
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Used for amino acids (of protein); basis of nucleic acid
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Importance of Phosphorous?
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ATP; DNA/RNA; phosphate backbone; phospholipid bilayer
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Importance of Sulfur
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Sulfur containing amino acids; S containing vitamins (biotin, thiamine)
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An example of another important element?
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Hydrogen
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What are growth factors (a.k.a organic growth factors)?
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Compounds that must be supplemented/added in the medium b/c bacteria are unable to synthesize.
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List examples of growth factors?
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Cholesterol for mycoplasma
Heme; purins, pyramidines |
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What is Energy needed for?
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1. Building blocks - protein synthesis
2. Transport process 3. Motility - flagella |
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The two Energy Sources for cells
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Sunlight and metabolism of chemical compounds
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Bacteria who use sunlight as an energy source are called?
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Phototrophs
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Bacteria who use chemicals as an energy source are called?
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Chemotrophs
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What are the two sources of carbon?
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Inorganic carbon and organic compounds
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Bacteria that use inorganic carbon as their energy source
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Autotrophs
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Examples of organic compounds...
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Sugar, lipids, amino acids
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Pathogenic microbes belong to what class?
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Chemoheterotrophs
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What are the four toxic forms of oxygen?
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1. Singlet oxygen (1O2)
2. Superoxide radicals (O2-) 3. Hydrogen peroxide and peroxide anion 4. Hydroxyl radical |
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Obligate aerobes
Ex and level of enzymes |
Ex. Pseudomonas aeroginosa (ubiquitous)
Abundance of SOD and catalase |
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Microaerophiles
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Ex. Helicopter pylori
Limited levels of SOD and catalase |
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Facultative anaerobes
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Ex. E. Coli
SOD and catalase at moderate levels |
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Obligate aerobes
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Can only grow in the presence of oxygen
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Microaerophiles
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Can tolerate between 2-10% of oxygen levels
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Facultative anaerobes
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Can grow in the presence or absence of oxygen. More rapid growth in the presence of oxygen.
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Obligate anaerobes
Ex and levels of enzymes |
Ex. Clostridium sps (intestinal bacteria)
SOD and catalase absent. |
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Obligate anaerobes
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Atmospheric oxygen is toxic
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Aerotolerant
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Obligate fermenters - always ferment carbon source. Don't use O2 for energy generation however the presence of O2 doesn't bother them.
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Aerotolerant
Example and enzyme levels |
Lacto bacillus sps, streptococcus pyrogens (strep throat)
Low levels of catalase and SOD |
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Superoxide radicals are neutralized by?
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Superoxide dismutase (SOD)
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Hydrogen peroxide and peroxide anion is neutralized by
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Catalase and peroxidase
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Peroxidase does not form what?
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Oxygen
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What vitamins also act as antioxidants?
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Vitamin E and C provides electrons and neutralizes the toxic forms of oxygen
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3 types of aerobic bacteria are?
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Obligate aerobes, microaerophiles, facultative anaerobes
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Two types of Anaerobic/Fermenters
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Obligate anaerobes, aero tolerant
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Which has more growth and why, aerobic or anaerobic/fermentation?
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Aerobic because when O2 is the terminal electron acceptor of the ETC max ATP is generated. More energy = more growth.
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Growth of microbes is directionally proportional to ....
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Nutrient availability
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Media types
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Physical state, chemical composition, functional types aka special types.
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List two nutritionally demanding bacteria?
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1. Neisseria Gonorrhea is nutritionally demanding and has 20-21 components. It hates competition and is a shy bacteria.
2. Syphillis bacteria we have no idea what it wants very difficult to grow. |
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Complex medium and Chemically defined medium can be either in liquid or solidified form (T/F)
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True.
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Do you need buffers In a complex or simple medium?
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Simple medium. In a Complex medium A.A. have a limited buffering capacity so you don't need one.
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Agar is a .....
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Complex polysaccharide derived from marine algae
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Does Agar have any nutritional value?
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No.
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Why does agar make a good medium?
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-Few microbes can degrade it
-dissolves at 100 degrees Celsius and solidifies at 45 degrees Celsius -agar is translucent and makes it easier to visualize colonies |
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Which media has components that inhibit growth of unwanted bacteria and encourage the growth of desired microorganisms?
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Selective Media
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Two examples of selective media in lecture and one we used in lab
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Thayer Martin media (TM) and Sabouraud's Media (SAB)
EMB agar |
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Thayer Martin media (TM) is used for the cultivation of what?
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Neisseria Gonorrhea. Contains 3 antimicrobials that inhibits all the gram (+) cells and gram (-) rods and fungi.
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Sabouraud's media (SAB)
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Has high concentration of salt & sugar w/low pH which supports fungal growth but not bacterial growth. We use it for the fungi experiment
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Physical state media types
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Solid, semisolid, and liquid
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What type of media is designed for easier detection and isolation of microorganism of interest from others growing on the same plate.
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Differential media
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Blood agar (and hemolysin)
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Contains blood from sheep/goat/chicken/rabbit. Sheep is the best. Hemolysin is an exotoxin that targets RBC's membrane
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The incomplete destruction of the red blood cells of hemolysin is called and an example is?
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Alpha hemolysis by streptococcus pneumonia
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What is Beta hemolysis and an example?
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Complete destruction of RBC's you will see a halo around cells an example is streptococcus pyogenes
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Gamma hemolysis
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No effect on RBC's
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2 Anaerobic growth media a.k.a reducing medium
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A. Sodium thioglycollate
B. Gas pak chamber |
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Sodium Thioglycollate
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Absorbs dissolved O2 and it makes it unavailable for bacterial growth. They have to use anaerobic growth.
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Transport media
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Used in clinical settings ensures
1. Individuals are not infected 2. Specimen not contaminated and cells are kept alive. Contains buffers and absorbents |
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Enrichment media
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Have components that favors the isolation of specific bacteria from low levels to detectable levels
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Vibrio cholerae and cold enrichment is an example of?
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Enrichment media. 4 degrees Celsius refrigerated temp all of the other bacteria will be suppressed but the v.c. Will keep going.
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Solid media types
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Test tube, petriplate and agar plant.
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Liquid media types
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Broth.
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Chemical composition
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1. Chemically defined/simple media - aka synthetic
2. Complex media- chemical composition unknown (peptones) |
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Chemically defined media
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Simple/synthetic: is one whose exact chemical composition is known
- has all required nutrients (glucose, salts) for the target microbes - in some, may contain vitamins / amino acids in known quantity |
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Complex medium
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Is one who's exact composition is unknown
- nutrients are derived from soy, yeast or beef extract / partial digests - vitamins and organic growth factors are provided by the extract |
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Why is the complex medium composition unknown?
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There is a peptone extract batch to batch variation.
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What are the advantages of a complex medium?
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It allows the growth of many microbes which are nutritionally challenged - you don't know what they need.
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Is E.Coli a fickle bacteria to grow?
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No. E.Coli is versatile since it can make all the vitamins and amino acids from the carbon source.
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List two special culture techniques
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Animal cultures
Low oxygen cultures |
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Most bacterial diseases are in what kind of relationship?
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Complex a.k.a biofilm -- the bacteria often benefit more than the host.
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Examples of biofilm bacteria...
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Microbes attached to tooth surface, mucous membrane of intestine and other body areas.
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Biofilms are observed in
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1. Regular households-- toilet bowl, water pipeline, shower curtain
2. Industry -- pipes, drains, bioremediation 3. Nature --slippery rocks 4. Health-- prostatitis, kidney infection, cystic fibrosis, and infections associated with medical device implant |
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Benefits to biofilm
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Hard to treat because community makes a capsule that is impenetrable. Cooperative interaction allows species to grow which wouldn't have grown in the first place.
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What bacteria is grown in animal cultures?
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M.leprae and treponema sps. In animals
M.leprae is grown in armadillos and treponema is grown in rabbit testicles Chlamydia and rickettsias in birds eggs and cell cultures. |
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Where is M. leprae cultivated?
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Grown in armadillos
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Where is treponema sps cultivated?
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Rabbit testicles
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Where is chlamydia and rickettsias cultivated?
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This are obligate intercellular parasites-always requiring healthy living cells to grow so they are cultivated in birds eggs and cell cultures.
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What bacteria is grown in CO2 incubators and candle jars?
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Neisseria Gonorrhea: capnophile and cornstarch, high CO2 low oxygen.
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If the relationship with an organism is harmful we call it?
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Antagonistic
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A mutually beneficial relationship is?
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Synergistic
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If organisms live in close contact and are interdependent than the relationship is?
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Symbiotic
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An example of a complex relationship is?
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Biofilm
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Bacteria that use organic compounds as a carbon source are called?
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Heterotrophs
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What enzyme detoxifies a superoxide radical?
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Superoxide dismutases (SOD)
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What enzyme(s) detoxifies the hydrogen peroxide and peroxide anion?
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Catalase and peroxidase
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What is the difference between a catalase reaction and per oxidase reaction?
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Catalase converts hydrogen peroxide to water and molecular oxygen. Hence the hydrogen peroxide test in lab when you look for bubbles to see if a bacteria has catalase.
Peroxidase breaks down hydrogen peroxide without forming oxygen. |
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What other vitamins do aerobes use as antioxidants?
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Vitamin C and E, they provide electrons that reduce toxic forms of oxygen
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What is the source of nutrients in agar media?
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Extract: peptones and soy/yeast/beef extract
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What are capnophiles?
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Capnophiles are microorganisms which thrive in the presence of high concentrations of carbon dioxide.
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What's an example of a capnophile?
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Neisseria gonorrhoeae requires carbon dioxide to grow.
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What are capnophiles?
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Capnophiles are microorganisms which thrive in the presence of high concentrations of carbon dioxide.
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What's an example of a capnophile?
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Neisseria gonorrhoeae requires carbon dioxide to grow.
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What is the significance of cornstarch in growing N. Gonorrhea?
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It grows best with cornstarch because it neutralizes the fatty acids.
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During which growth phase are bacteria more susceptible to antimicrobial drugs?
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Log phase, because drugs that target metabolism or cell wall structure are most effective in this phase.
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During which growth phase are bacteria more susceptible to antimicrobial drugs?
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Log phase, because drugs that target metabolism or cell wall structure are most effective in this phase.
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What is the stationary phase?
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When the number of dying cells equals the number of cells being reproduced.
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What is generation time (gt)?
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The time it takes a population to double.
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What is generation time (gt)?
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The time it takes a population to double.
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What is the generation time (gt) of e.coli?
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20 minutes
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What is generation time (gt)?
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The time it takes a population to double.
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What is the generation time (gt) of e.coli?
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20 minutes
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What is the generation time (gt) of mycobacterium?
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24 to 48 hours (mycolic acid synthesis is slow)
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What are three factors that contribute to the stationary phase?
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1.consumption of essential nutrients
2.waste products accumulation at toxic levels 3. pH changes (contributed by actively growing cells. |
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What are three factors that contribute to the stationary phase?
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1.consumption of essential nutrients
2.waste products accumulation at toxic levels 3. pH changes (contributed by actively growing cells. |
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Where are the cells getting their energy and nutrients during the stationary phase?
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Other dead cells
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