1) ListenIn the lab you are testing a bacterium's oxygen requirement for growth. You growyour bacterium in a test tube, without shaking at the appropriate temperature. Thenext day you find that your bacterial culture is growing only at the top surface (ie atthe top of the tube closest to the cap) and not dispersed throughout the test tube.What term would be used to describe the oxygen requirement of this bacterium?O A) Obligate aerobe.O B) Microaerophile.O C) Anaerobe.D) Obligate anaerobe.E) Facultative anaerobe.

On the basis of the oxygen requirement, microorganisms can be classified as aerobic and anaerobic.

In the lab you are testing a bacterium's oxygen requirement for growth. You grow your bacterium in a test tube, without shaking at the appropriate temperature. T next day you find that your bacterial culture is growing only at the top surface (ie the top of the tube closest to the cap) and not dispersed throughout the test tub What term would be used to describe the oxygen requirement of this bacterium? O A) Obligate aerobe.

In the lab you are testing a bacterium's oxygen requirement for growth. You grow your bacterium in a test tube, without shaking at the appropriate temperature. T next day you find that your bacterial culture is growing only at the top surface (ie the top of the tube closest to the cap) and not dispersed throughout the test tub What term would be used to describe the oxygen requirement of this bacterium? O A) Obligate aerobe.

Basic Clinical Laboratory Techniques 6E

6th Edition

ISBN:9781133893943

Author:ESTRIDGE

Publisher:ESTRIDGE

Chapter7: Basic Clinical Microbiology

Section7.4: The Gram Stain

Problem 2RQ

See similar textbooks

Similar questions

Using your fingers, you are asked to aseptically touch the surface of a sterile agar plate. Illustrate the possible result from this step if your fingers are (a) unwashed – touched various things prior to placing on agar surface, and (b) washed with soap or disinfected with 70% alcohol. Describe the relative abundance of microbial growth observed on the plates. List and draw the possible characteristics of an isolated bacterial colony that can be observed based on type of (a) margin, (b) elevation, (c) texture, and (d) optical property.
Suppose you spilled two cultures of Salmonella typhimur-ium (each containing 100,000 cells) on your lab bench. You im-mediately applied the same disinfectant to both cultures at thesame time. One culture had been freshly grown for 36 hours andthe other culture is 2 weeks old. If the kill ing rate of the disin-fectant is 90% per minute, do you think that microbes in bothcultures will be completely killed after 6 minutes? Why or whynot?
A lab technician is working with a bacterium in pure culture (in 5 ml of liquid media in a test tube). The bacterium is a mesophile that can infect humans. Which of the following is NOT true (with regards to temperature conditions for this bacterial culture)? Lowering the temperature to -10 deg C for at least an hour will likely kill all the bacteria. Placing the tube at 37 deg C will likely facilitate rapid growth of the bacteria. Raising the temperature to 90 deg C for at least an hour will likely kill all the bacteria. Placing the tube at 4 deg C will likely slow or halt growth of the bacteria.
You observe a culture of bacterial cells that has been grown in liquid thioglycolate media and notice that there is only turbidity at the very bottom of the tube. What does this imply about the culture? O The bacterium is likely a facultative anaerobe. The bacterium is likely an aerotolerant organism. O The bacterium is likely an anaerobe. O The bacterium is likely an aerobe.
Supposed you are to observe an unknown bacterial slide. In your initial observation, it appears to be in fading color and the shape of the specimen seems to be diffused. How are you going to troubleshoot the focusing of the specimen for you to identify clearly the bacteria?
a. What oxygen requirements do your think this bacterium will have (obligate aerobe, obligate anaerobe, facultative anaerobe, aerotolerant anaerobe, or microaerophile), and why? b. You run a thioglycollate test of your isolated bacterium. Based on your response to Part A, which thioglycollate tube best represents the result you would expect for your bacterium? Explain your response. If the result you would expect is not represented, explain what the tube should look like. c. What would you expect to be the result of a catalase test of your bacterium? d. What techniques or specialized equipment, if any, would you need to grow cultures of this bacterium?
If you altered the conditions under which bacterial growth normally occurs (i.e. increase the temperature of incubating a culture from 35 to 40°C), what effect would this have on the bacterial growth curve of the organism under study?
You are given a 1 gram soil sample of unknown bacterial load. After doing 10-fold serial dilutions of the soil in sterile water, 100 uL volumes are taken from each dilution for preparation of pour plates. Following incubation, each half of the 10-8 plate has 46 colonies.a) What was the dilution factor?b) How many bacteria were present in the soil?2. Staphylococcus aureus divides every 20 minutes. A culture begins with 10 bacterial cells.a) After 5 hours, how many generations have occurredb) After 5 hours, how many bacteria are present?3. How many milliliters would you need to prepare a 10-2 dilution from a 10ml starting culture?
(c) Public health scientists wanted to investigate the effect of ionising radiation on the growth of Salmonella typhimurium in the presence of antibiotics. They grew bacterial colonies of Salmonella typhimurium in petri dishes labelled A, B and C. The Petri dishes were kept at 36°C for 48 hours, with scientists observing the bacteria every 24 hours. The results for this investigation are below. Petri dish A B с Treatment Was subjected to ionising radiation followed immediately by a dose of antibiotic X An equal amount of antibiotic X was added (as was added to Petri dish A) Was given neither ionising radiation nor antibiotic X After 24 hours Small spots of growth on surface No growth Growth across whole surface After 48 hours (ii) Identify the purpose of petri dish C. Large spots of growth on surface No growth Growth across whole surface (i) Explain the effect of the ionising radiation on the bacteria. (iii) Explain why scientists must continue to develop new antibiotics.
1. Table 1 lists a typical recipe for growing bacteria in the lab. A researcher discovered a potentially new species of bacterium from a soil sample and attempted to grow it in this media. Unfortunately, the bacterium did not grow. Identify at least three components that you suggest adding to the medium to enable growth. Provide a reason for adding each component. Table 1. per 1000 mL 1g Bacteria culture media NazHPO4•7H2O KH2PO4 3g 5 g 1 g 0.4% (wt/vol) 0.2% (wt/vol) NaCl NHẠC1 Glucose Casamino acids
As part of an experiment where absorbance values are measured using a spectrophotometer, you are taking readings of your sample every 20 minutes. The non-motile microbe you're testing has a generation time of roughly 20 minutes at an incubation temperature right around room temperature. Things start out fine, with the expected results — as time goes by at the correct incubation temperature, absorbance starts to rise as the medium starts to become more cloudy with growing microorganisms. But roughly 2 hours into the process, you notice that the absorbance levels flatten out, and then start to decrease unexpectedly. What is most likely taking place in your experiment?
You are given an unknown bacterium in the lab and have to determine unknown bacterium's oxygen needs. You place the organism in a shake tube and after 24-hours observe significant turbidity near the surface of the media and the turbidity decreases as you move toward the bottom of the tube; however there is still apparent growth. How do you classify this organism? O Microaerophile O Facultative anaerobe O Obligate aerobe O Obligate anaerobe Question 14 1 pts