Term
| a nutrient agar plate that contains streptomycin is best described as what type of media? |
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Definition
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Term
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Definition
| mutation that causes a single nucleotide change, which then leads to a change in the amino acid sequence of a peptide |
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Term
| if you innoculated a nutrient agar slant of Serratia marcescens and left it out over night on your bench, in the morning you would most likely see? |
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Definition
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Term
| 2 ways to determine the concentration of cells in a liquid culture |
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Definition
| serial dilution, spectrophotometer |
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Term
| Why is it important to autoclave thioglycollate media before innoculating it with bacteria like Clostridium sporogenes? |
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Definition
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Term
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Definition
| thermophile, extremophile |
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Term
| when Pseudomona aeruginosa grows it may produce ? |
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Definition
| pyocyanin- a substance that inhibits bacterial growth |
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Term
| in molds where would you expect to find most of the nutrient uptake occuring? |
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Definition
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Term
| 2 reasons why the human throat is an ideal environment for microbial growth to occur? |
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Definition
| mucus is a good media, turns over nutrients/waste, large aerobic surface area |
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Term
| to determine the antibiotic ability of various chemicals relative to one another we looked for |
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Definition
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Definition
| nutrients suspended in liquid. Used to grow large numbers of microorganisms |
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Definition
| solidifying agent added (agar). used for fermentation studies, bacterial motility and anaerobic growth. |
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Term
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Definition
| solidifying agent added (agar) used for: surface growth of microorganisms in order to observe colony appearance, pure culture isolation, storage of cultures, observe specific reactions |
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Definition
| a polysaccharide composed of galactose obtained from raw seaweed. Agar dissolves |
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Term
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Definition
| a polysaccharide composed of galactose obtained from raw seaweed. Agar dissolves at 100 degrees C and solidifies at 42 degrees C |
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Term
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Definition
| liquid agar hardened at slanted position |
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Definition
| liquid agar hardened in upright position |
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Definition
| liquid agar poured into petri dish and allowed to harden |
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Term
| chemically defined or synthetic media |
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Definition
| composed of known amounts of pure chemicals |
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Term
| complex or nonsynthetic media |
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Definition
| composed of complex materials rich in vitamins and nutrients (beef extract, yeast extract, and peptone) |
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Term
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Definition
| process of rendering a medium or material free of all forms olf microorganisms |
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Definition
| items are sterilized by exposure to steam at 121 degrees C and 15lbs of pressure for 15 minutes. |
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Term
| microorganisms including endospores will not survive longer than about ___ minutes |
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Definition
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Term
| is it high temp or pressure that kills microorganisms |
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Definition
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Term
| bacterial reproduction entails |
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Definition
| increase in cell size, duplication of entire chromosome, synthesis of new cell wall and plasma membrane and division (binary fission) |
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Term
| 4 phases of exponential growth curve |
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Definition
| lag, log, stationary, death |
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Term
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Definition
| freshly innoculated cells grow accustomed to their surroundings, needing to become accustomed to pH, salts, nutrients, oxygen levels, light, temperature. |
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Term
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Definition
| bacteria begin dividing on a fairly normal schedule(generation time) based on species and media. cell counts jump rapidly in a short period of time due to the doubling of the population. |
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Term
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Definition
| cells are at max growth potential, limited by nutrient concentration being too low, metabolic products which inhibit cell, space limitations (densely packed) . cell numbers remain same but not a static phase. cells are continuously growing up to a point and then stopping, population keeps moving |
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Term
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Definition
| population of cells declines |
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Term
| how do we count cell numbers? |
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Definition
| microscopic counts, electronic counts, viable counts (dilution series) |
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Term
| how do we count cell mass? |
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Definition
physical measures (weight, volume)
chemical measures( atomic methods, protein/DNA counts)
chemical activity measures(gas consumption/production)
turbidity measures (optical density) |
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Term
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Definition
| term used for innoculated broth cultures with growth. (when there is growth the broth becomes cloudy or foggy, this can be given a quantitative number using UV spectroscopy. |
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Term
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Definition
| measure an objects absorbance (AKA optical density) of light from source, as well as its transmittance of that light. |
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Term
| spechtrophotometers have what issues? |
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Definition
| since dead cells refract as well, it is difficult to see the death phase and occasionally one will not appear at all, machines can be finicky, physics get in way, (limits to linear lines vs concentration) |
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Term
| T or F? spectrophotometer readings are okay for quick estimations, they will not give you a physical number for the bacteria |
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Definition
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Term
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Definition
| use a broth culture which is serially diluted and plated on media to grow. the amount of colonies which grow are directly related to the amount of bacteria present in sample |
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Term
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Definition
| colonies which grow in conjunction with the used dilution factor. |
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Term
T or F
given viable counts we can accurately estimate the amount of bacteria in a culture. |
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Definition
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Term
| Can you do a calculation of generation time with turbidity measurements? |
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Definition
| no, generation time requires you have a starting and ending CFU/mL. |
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Term
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Definition
| pouring a small amount of sample over an agar plate and spreading it along the surface until the agar absorbs the sample |
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Term
T or F
serial dilutions will not always give good results, more often than not most of plates will be either too over grown with colonies or have extremely few |
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Definition
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Term
| plates should be counted only if there are ______ well defined colonies |
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Definition
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Term
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Definition
| inhibit microbial growth but do not kill the microbe (usually requires immune system) |
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Term
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Definition
| kills bacteria provided concentration is high enough |
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Term
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Definition
| kills bacteria provided concentration is high enough |
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Term
| if no growth occurs on a plate with a reagent, restreak onto media with no reagent. if growth occurs? |
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Definition
| the agent was bacteriostatic |
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Term
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Definition
| agent was bacteriocidal (bacteria was killed/rendered nonviable |
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Term
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Definition
| a halo which has formed around a disk which contains various chemicals due to the death or inhibition of bacterial cells. (bacteriocidal agents will also form zones of inhibition) |
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Term
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Definition
| the harmful effect of one microorganism on another |
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Term
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Definition
| a specific substance produced by a microorganism which exterts an inhibitory effect on certain other organisms |
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Term
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Definition
| a group of gram + bacteria found in soil and decaying vegetation, most produce spores. distinct earthy odor which results from production of volatile metabolite, geosmin. make soil smell like soil |
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Term
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Definition
| over 2/3 clinically useful antibiotics |
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Term
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Definition
| inhibits growth of eukaryotic organisms and molds but not streptomyces, antibiotics can be isolated from soil with addition of cyclohexamide |
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Term
| P. aeruginosa is known for? |
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Definition
| resistant to many antibiotics due to permeability barrier afforded by its outer membrane LPS. (natural habitat is soil, living in assoc. w bacilli actinomycetes and molds it has developed resistance to a variety of naturally occuring antibiotics) |
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Term
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Definition
| a blue pigment produced by some strains of P. aeruginosa, which can act as an antibiotic to other organisms (especially gram +) |
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Term
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Definition
| a naturally occuring strain of bacteria, typically seen when the cell is not stressed greatly |
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Term
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Definition
| a bacterium which possesses a different genetic make up (genotype) This may or may not result in physical change of bacteria (phenotype) |
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Definition
| by changing a single base pair of DNA, adding or removing large sequences. by changes in physical or chemical environment (UV light, heavy metals, xrays) |
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Term
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Definition
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Term
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Definition
| mutations where the base pair change does not alter the amino acid coded by that codon (CGA-CGG still gives an arginine) |
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Term
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Definition
| can cause a mutant bacteria to gain dominance over its wild type |
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Term
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Definition
| mutations which cause a change in the amino acid sequence ( AAA-AAC changes the amino acid from lysine to asparagine) |
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Term
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Definition
| mutations which cause a codon to become a stop codon which can cause a shortening of the coded protein |
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Term
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Definition
| mutations which add or remove segments of DNA. Results in shifting of reading frame which can change everything down the line. |
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Term
| how can we select for mutants to appear |
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Definition
| altering conditions we put bacteria into. using selective media which forces bacteria to adapt or die. limiting nutrients, altering pH etc, addition of antibiotic, etc. |
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Term
| frequency of mutation calculation |
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Definition
| # of mutant CFU's divided by inoculated CFU's. |
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Term
| bacterial variation does not always mean a mutation has occured. Occasionally the environment can influence a gene or gene set ro produce a different level of expression (pigment production, motility, sporulation, toxin release, nutritional requirements) |
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Definition
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Term
| Serratia marcescens produces a pigment with is partially dependant on temp |
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Definition
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Term
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Definition
| cannot grow in presence of oxygen at atmospheric levels. due to lack of enzyme which can protect them from oxygenic damage |
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Term
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Definition
| can use oxygen, but when none is present can also undergo anaerobic respiration/fermentation |
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Term
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Definition
| can survive in presence of oxygen, but do not use it for their terminal electron acceptor |
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Term
| to cultivate strict anaerobes |
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Definition
| oxygen needs to be removed from the media and surrounding area |
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Term
| how is oxygen removed from media |
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Definition
| autoclaving, gas packet when mixed with water convert O2 to CO2 and H+ ions |
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Term
| although some molds cause disease or food spoilage, some are useful for? |
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Definition
| biodegradation, production of various foods, beverages, antibiotics and enzymes |
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Term
| molds secrete hydrolytic enzymes from predominantly the hyphal tips. these enzymes degrade complex biopolymers such as starch, cellulose and lignin into simpler substances which can enter the hyphae. |
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Definition
| in this way molds play a major role in decomposition of organic material. |
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Term
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Definition
| many molds secrete, together with hydrolytic enzymes, inhibit the growth of competing microorganisms. |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
| bacteria that live in moderate environments, akin to what we normally live in. |
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Term
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Definition
| bacteria that live in harsh and extreme environments (like underwater hydrothermal vents) |
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Definition
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Definition
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Definition
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Definition
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Definition
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Definition
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Definition
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Definition
| produces a highly heat resistant DNA polymerase which is now used in polymerase chain reactions (PCR)in labs. Taq polymerased |
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Definition
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Definition
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Definition
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Definition
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Definition
| eukaryotic microorganisms classified in the kingdom Fungi |
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Definition
| asexually by budding, some by binary fission |
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Term
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Definition
| used in baking and fermenting alcoholic beverages. model organism in modern cell biology research, most thoroughly researched eukaryotic organism |
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Term
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Definition
| strike when opportunity like compromised immune system (candida albicans) |
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Term
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Definition
| internal organs, blood vessels, cerebrospinal fluid, and urine |
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Term
| bacteria which colonize our body are responsible for |
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Definition
| keeping potentially pathogenic strains from gaining a foothold in the body |
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Term
| staphylococcus epidermidis/aureus |
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Definition
| found frequently on skin. if it gains access to open wound, staph infections can occur |
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Term
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Definition
| present in upper respiratory tract of about half population. if it invades lower tract can cause pneumonia. causes 95% of all bacterial pneumonia |
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Term
| some strains of E. coli cause |
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Definition
| intestinal infections, urinary tract infections, and neonatal meningitis |
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Term
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Definition
| quintessential opportunistic pathogen of humans. invade virtually any tissue. leading cause of hospital acquired (nosocomal) gram-negative infections |
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Term
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Definition
| methicillin resistant staph aureus |
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Term
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Definition
| vancomycin resistant staph aureus/enterococcus |
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Term
| nasal passage, throat and lungs |
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Definition
| provide a unique environment for microbial growth |
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Term
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Definition
| excellent media, constantly turning over nutrients/waste |
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Term
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Definition
| largely aerobic, although large surface area contributes to small anoxic regions |
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Term
| staphylococcus, streptococcus and neisseria are |
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Definition
| very common in respiratory tract |
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Term
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Definition
| blood agar, phenethyl alcohol agar plate |
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Term
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Definition
| blood agar, mannitol salt plate |
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Term
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Definition
| anaerobic catabolism of organic compounds in the absence of an external electron acceptor |
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Term
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Definition
| contains the disaccharide lactose that can be hydrolyzed by the enzyme lactase into glucose and galactose. |
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Term
| glucose and galactose fermented to |
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Definition
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Term
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Definition
| process by which organisms produce proteo |
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Term
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Definition
| process by which organisms produce proteolytic enzymes to digest proteins into peptides (milk,casein is digested into peptones and amino acids) |
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Term
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Definition
| a pH indicator that is purple to blue at neutral to alkaline pH and pink under acid conditions |
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Term
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Definition
| the solution should turn pink. |
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Term
| if lactose is not fermented |
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Definition
| proteins are instead used for energy, the solution will become alkaline and more blue |
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Term
| casein protein may be digested |
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Definition
| coagulating milk to form a curd |
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Term
| casein may be metabolized all the way down to |
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Definition
| individual amino acids. this process is called peptonization, results in a clear(not milky) liquid that is usually brown in color. |
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Term
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Definition
| partial breakdown of blood cells. green tinge to develop around the colonies. |
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Term
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Definition
| full lysis of blood cells, causing clear zone to appear around colony |
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Term
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Definition
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Term
| on mannitol salt plates, looked for |
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Definition
| staphylococci (clusters of cocci) |
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Term
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Definition
| long chains of carbon fatty acids (60-90) give bacteria a waxy coating. makes it resistant to drying out, and nutrient uptake difficult and slow growth. |
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Term
| Mycobacterium tuberculosis |
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Definition
| a bacteria which uses mycolic acids |
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Term
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Definition
| gram - rods, ability to ferment lactose to an acid end product, along with gas. frequently found in the gut of warm blooded animal feces, easy to cultivate and usually non pathogenic |
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Term
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Definition
| entire coliform population, lactose fermentors |
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Term
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Definition
| sub section of total coliform that can grow in the presence of bile salts and at higher temps (44 degrees C) |
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Term
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Definition
| sub set of fecal coliform and best indicator of fecal contamination in drinking water, differentiated by further metabolic differences |
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Term
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Definition
| broken sewage pipe, large areas of pavement have excessive run off, dead animal carcasses, warm temp, high population, large amounts of rain |
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Term
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Definition
| water which is free of detectable levels of coliform bacteria |
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Term
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Definition
| inhibits (selects against) gram negative bacteria |
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Term
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Definition
| 7.5% NaCl and is therefore selective for halotolerant or halophillic bacteria |
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Term
| positive mannitol fermentation |
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Definition
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Term
| XLD (xylose lysine deoxycholate) agar |
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Definition
| selective against normal coliforms (E. coli and gram + bacteria) |
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Term
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Definition
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Term
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Definition
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Term
| EMB (eosin Y-methylene blue) agar |
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Definition
| tests for lactose fermentation |
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Term
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Definition
| green metallic (E. coli) or pink colonies |
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Term
| TSI (triple sugar iron) agar |
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Definition
glucose fermentation=red slant, yellow butt
lactose/sucrose fermentation=yellow slant and butt
gas production=split in agar
H2S production=black |
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Term
| CTA (cystine trypticase) agar |
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Definition
tests for breakdown of carbs
sugar fermentation = yellow |
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Term
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Definition
test for presence of urease (breaks down urea)
urease + = red (alkaline) |
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Term
| normal flora of skin include |
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Definition
| yeasts and bacteria. yeasts primarily Pityrosporum |
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Term
| staphylococcus epidermidis |
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Definition
| pathogenic on wounds, catheters and heart valves |
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Term
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Definition
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Term
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Definition
| responsible for dandruff when in large numbers |
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Term
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Definition
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Term
| larger variety of flora of throat and nasal passages than of skin |
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Definition
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Term
| normal flora of throat and nasal passages |
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Definition
| streptococcus, neisseria, haemophilus, anaerobic bacteriodes |
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Term
| pathogenic species of flora of throat and nasal passages |
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Definition
| Staphylococcus aureus, corynebacterium diptheriae, neisseria meningitides, haemiophilus influenzae |
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Term
| method of bacterial isolation and identification of nasal flora most commonly used |
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Definition
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Term
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Definition
| distinctly seperates and identifies Streptococcus and Staphylococcus strains |
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Term
| Streptococcus colonies appear |
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Definition
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Term
| Staphylococcus colonies appear |
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Definition
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Term
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Definition
| EMB, TSI slant, CTA slants |
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Term
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Definition
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