Microbiology UTA 2460 - Lab Practical 2 Questions with Verified Answers

Microbiology UTA 2460 - Lab Practical 2 Questions with Verified Answers What is the role of resazurin in fluid thioglycolate medium... Resazurin indicates the presence of oxygen in the media A bacterial isolate is subcultured to two blood agar plates, one of which is incubated in an anaerobe jar, and the other is incubated on a shelf in the incubator. After incubation, growth is observed on the plate from the anaerobe jar, but there is not growth on the plate incubated on the incubator shelf. Based on these results how would this organism be categorized... obligate anaerobe Where would you predict an facultative anaerobe would grow in a tube of fluid thioglycolate medium... throughout the tube The pink color in the top of the broth in an FTM tube indicates... the presence of oxygen Both human pathogens and normal microbiota are typically classified as... mesophiles Taq polymersae is a DNA polymerase enzyme that demonstrates maximal activity at 72C. The organism from which this enzyme was isolated would most likely be classified as a... thermophile Vibrio cholerae is the bacterium responsible for cholera, a GI tract infection. Normally, it takes the ingestion of over one million bacterial cells to cause infection, but the consumption of antacids significantly lowers this number. What does this tell you about the likely classification of V. cholerae in terms of pH preference... it is likely an alkaliphile How does pH negatively affect the metabolism of microorganisms... pH changes can denature enzymes Why can jams and honey be stored at room temperature for long periods of time... the high sugar content causes plasmolysis of bacterial cells Microorganisms that can grow at salt concentrations as high as 15-30% are known as... halophiles An experiment involves the inoculation bacteria onto a variety of media with NaCl concentrations ranging from 1% to 25%. Which of these media is most likely to be isotonic with the bacterial cells... 1% Which of the following would be appropriately sterilized using UV radiation... stainless steel surface in biological safety cabinet used for media preparation Which of the following infectious agents is least likely to be damaged by UV exposure... prions When two adjacent thymine molecules are joined by a covalent bond as a result of exposure to UV light, this structure is referred to as a... thymine dimer How are agar plats inoculated for disk diffusion testing of antiseptics and disinfectants... a swab is used to inoculate the entire surface of the plate, producing a lawn of growth How is an antiseptic different from a disinfectant... an antiseptic is used to remove to kill microorganisms on tissue, whereas a disinfectant is used to remove or kill microorganisms on inanimate objects