You are working with an intestinal bacterium of humans, which you have in pure culture (in liquid media in a test tube). Which of the following is true regarding adjusting the temperature of this bacterial culture? Placing the tube at 37 deg C will likely slow or stop growth of the bacteria. Raising the temperature to 80 deg C for at least an hour will likely kill all the bacteria. Lowering the temperature to -20 deg C for at least an hour will likely kill all the bacteria. Placing the tube at 4 deg C will likely allow the bacteria to grow at their maximum rate.

Q: starting with four bacterial cells per milliliter in a rich nutrient medium, with a 1-hour lag phase…

A: Bacterial Growth --Bacterial Cell growth is proliferation of bacterium in to daughter cells ,…

Q: What are the 2 most important reasons for using a positive control in Microbiology tests? What are…

A: A control test is used to set a reference for comparison in microbiological tests. It helps the…

Q: Here is an image of a UV-irradiation (wavelength 254nm) experiment performed on a plate of E. coli…

A: Conceptual Introduction UV radiations are known to cause genetic damage and cessation of bacterial…

Q: What conclusion would you draw if the numbers of bacterial colonies in were the same on the control…

A: Bacteria are unicellular and prokaryotic organisms that live in wide variety of environments. It…

Q: identify the organisms in  an unknown culture. You find that the culture contains two gramnegative…

A: A culture is a medium to grow bacteria and other microorganisms  It provides the bacteria with…

Q: microbiology: Aseptic Culture Techniques Lab Explain why a loop or needle is flamed before it is…

A: The process of introducing a microorganism in a plate or a tube containing culture media is called…

Q: You prepared a 7x 10^5x dilution from your bacterial culture, plated 0.2 ml of it on a Petridish and…

A: A colony-forming unit (cfu) is a unit used in microbiology to estimate the number of viable bacteria…

Q: 1 mL of a juice sample is taken and diluted in 9 mL culture medium, subsequently, this suspension is…

A: Petroff- Hausser chamber is a chamber used usually for sperm and bacterial count. Number of bacteria…

Q: How could you determine whether the turbidity in your LB tube was from a mixture of different…

A: Introduction: The term "turbidity" describes how cloudy a solution is. Turbidity in a Luria Broth…

Q: in 5 hours, your bacterial culture went from a concentration of ~105 CFU/mL to ~1.6 x 106 CFU/mL,…

A: n=1.6x106 CFU/ml N=(no of cells at the beginning )=105 CFU/ml n=Nx2x x=no. of generation…

Q: Dilute cells from an old culture 1:200 into 5 mL of fresh media. What volume of the old culture…

A: Introduction Dilution is the process of lowering the concentration of a solute in a solution by…

Q: how many bacteria/ml of the diluted broth would be present on average

A: 37 bacteria/ml of the diluted broth would be present on average.

Q: EXPERIMENT : REMOVAL OF WATER FROM MICROBIAL CELLS USING FREEZE  DRYING METHOD Objective To learn…

A: Introduction Freeze Drying Is A Technique That Includes Sucking A Completely Frozen Sample To Remove…

Q: You observe a culture of bacterial cells that has been grown in liquid thioglycolate media and…

A: Thioglycolate broth is a differential medium enriched with several nutrients such as casein, yeast…

Q: Which of the the following results of the extracellular enzyme tests is FALSE?    Question 3…

A: Answer: Extracellular Enzymes or Exoenzymes are the enzymes secreted by the organisms or cells and…

Q: The bacterium Dontuplodemeus tocheggus has a generation time of 20 minutes. Starting with one cell…

A: Bacteria are a family of rod-shaped bacteria that are often found in soil or water. They are known…

Q: Please examine the following data of absorbance values (@ 600nm) for a bacterial culture through…

A: 1. Log base 10 values of absorbance calculated are as follows: Time (min) log10Abs 0…

Q: You are testing a potential new antibiotic for its effectiveness at killing Streptococcus…

A: Drugs are medications that are taken in the prescribed amounts under the supervision of doctors to…

Q: For a bacterium that prefers a neutral pH and has an optimal (best) growth pH of 7, how would growth…

A: The optimum pH for the growth of microbes is the favorable pH for that organism. The lowest pH value…

Q: Which of the following is true regarding microbial tests that lead to color change in tubes used to…

A: Option 1 and 4 are correct. There are multiple tests involving color change for bacteria…

Q: Joshua is showing a bacterium having high pH requirement for its growth. With this, he has to…

A: For titration low conc. of Acid and base used because at the time of titration, we add volume. if…

Q: What would you expect to see if you cultured Gram-positive, lactose-fermenting bacteria on MacConkey…

A: Given: What would happen if you culture gram positive, lactose fermenting bacteria in MacConkey…

Q: EXPERIMENT : REMOVAL OF WATER FROM MICROBIAL CELLS USING FREEZE  DRYING METHOD Objective To learn…

A: Freeze drying is a method that involves placing a completely frozen sample under a vacuum to remove…

Q: What incubation temperature is preferred for the growth of most medically important bacteria?…

A: Various bacteria have different incubation temperatures-hyperthermophile (60 degrees C and upwards)…

Q: On which of the following types of media would you expect untransformed bacteria to grow on?

A: In this question, we have to answer which kind media support the growth of untransformed bacteria.

Q: a. What can you observe in viewing your stained bacterial slide under the microscope if you fixed a…

A: The staining is a very important process in microbiology that is used to identify specific…

Q: Here is an image of a UV-irradiation (wavelength 254nm) experiment performed on a plate of E. coli…

A: UV light at 254 nanometers is used as a sterilization method in medical environments, labs,…

Q: You have a culture of cells at 3.5 x 108 cells/ml and you want to prepare a fresh 5 ml culture with…

A: The concentrated stocks can be diluted using the dilution formula. The dilution formula is:- C1V1 =…

Q: A slant is inoculated with 100 E.coli cells. The slant is left at room temperature where the…

A: Bacterial cells divide by binary fission to produce two daughter cells. The growth of a bacterial…

Q: You accidentally switch the Crystal violet and Safranin steps during your Gram stain. When you look…

A: The gram staining procedure that is used for staining and visualizing the bacteria. The bacteria are…

Q: In theory, if a 1-liter culture of rich medium is inoculated with 3 bacterial cells per milliliter,…

A: Generation time is the time taken for the doubling of the single cell. According to data given in…

Q: SEE EXAMPLE IN THE IMAGE A mixture of 0.20M acetic acid and 0.30M sodium acetate is given. Calculate…

A: The Henderson Hasselbalch equation for calculation of the pH of a solution of weak acid and its…

Q: Starting with 10 bacterial cells per milliliter in a sufficient amount of complete culture medium…

A: Bacteria are organisms that are found almost everywhere on earth and are free-living cells that are…

Q: Which of the following samples are expected to cause a decrease in absorbance over time when…

A: Ensuring adequate light reaching a detector by using water colloidal solutions in light or X-ray…

Q: What color would the bacterial cells have when viewed microscopically after the following treatment?…

A:

Q: The culture you are working has a doubling time of 2 hours and a cell density of 3 x 106 cells per…

A: A serial dilution is a process of sequential dilution in order to decrease the density of cell…

Q: A certain medium has the following composition: Glucose                15 g Yeast extract      5 g…

A: Since you have asked as question with multiple subparts, we will answer only first three subparts…

Q: What color would the bacterial cells have when viewed microscopically after the following treatment?…

A: Gram staining is a technique to distinguish between two broad types of bacterias on the basis of…

Q: You have a starter culture containing 8 x 109 cells per mL, from which you take 10 mL to inoculate a…

A: The generation time of culture is considered to be the time at which it doubles and the mean growth…

Q: You dilute 1 mL of bacterial culture with 99 mL of water.  What is the resulting dilution factor?

A: Dilution factor:In order to calculate the Dilution factor, the final volume is to be divided by the…

Q: You are asked to add 2 mL of bacterial culture to 98 mL of water. What is your dilution factor? Show…

A: Introduction :- A test to determine whether you have a bacterial infection is a bacterium culture.…

Q: How many different types of colonies can you find on the blood agar plate? describe each. (As shown…

A: Blood agar is general medium that is provided with the nutrients and can be use as a general growth…

Q: Imagine you accidentally applied water during the decolorization step instead of ethyl alcohol.…

A: Gram positive bacteria has thick peptidoglycan layer and thin outer membrane. Gram negative bacteria…

Q: You are testing ground beef to determine how many bacteria are present per gram of meat. You place 1…

A: Given: Number of colonies = 122 The volume of sample plated in ml = 0.1 ml Dilution = 10-3 Dilution…

Q: Which of the following takes the LONGEST to kill a live culture of vegetative bacterial cells?   a)…

A: A "microbe" is a living entity that is so tiny that it cannot be seen with the naked eye.…

Q: The soil bacterium Azotobacter can be enriched from soil using liquid media, which must contain the…

A: Azotobacter are nonsymbiotic bacteria. They are capable of fixing nitrogen aerobically.

Q: A bacterium has a generation time of 30 minutes. You transfer cells from an exponentially growing…

A: The bacterial cell follows the development of new daughter cells by the division of DNA. In…

Q: Why should agar media be completely dissolved before they are dispensed in tubes and plates? What…

A: Introduction  A growth medium, also known as a culture medium, is a solid, liquid, or semi-solid…

Q: Suppose your Professor handed you a test tube with 2.0mL of E.coli broth culture and told you to…

A: In both basic and applied research, "microbiology" is a highly significant area. Proteomics,…

Q: If you have a culture with 1 x 106 cells per ml, how could you use serial dilutions to obtain a…

A: Serial dilution  It is a method of stepwise dilution of a concentrated solution to get the desired…