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?

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.

Use the attached image to help explain the results on the NA and ECM plates. Be sure to address why each sample is either able or unable to grow on each plate and include the genotype(s) of the cells which are capable of growth.

How do water and salts exit the blood and convert into urine? In your answer, please discuss the following terms: glomerulus, Bowman’s capsule, collecting duct.

you are given a mixed culture of s. aureus, E. coli and P. aeruginosa. how would you isolate each other from this mixed culture?( Besides using plate technique)

During the heat shock step, a student accidentally heated the cells at 42°C for 5 minutes. Only a few colonies were found on the agar plates at the end of the experiment. Explain the results.

you are given a mix culture of S aureus, E. coli and P. aeruginosa. besides using the streak plate method what other method could you choose to separate the bacteria? the result you will be looking for and interprete the result.

Which isolation technique is best used in isolating microorganisms (in countable good plates) from a gram of soil sample with expectedly high microbial count?  A. Streak Plate technique B. Serial Dilution-Pour Plate technique C. Spread Plate technique D. Hanging Drop technique 2. Which materials are needed in isolating bacteria using Streak Plate technique? Check all that apply.  ( )nutrient agar plate ( ) inoculating loop ( ) microbial inoculum ( ) flame source 3. Which term refers to that solution of sterile distilled water/normal saline/peptone water used to "thin out" dense microbial populations in Serial Dilution-Pour Plate technique used in the isolation of microorganisms?  A. inoculum B. culture medium C. diluent D. microbial culture

I'm having trouble identifying the type of bacteria I have cultured. I know that it is gram-negative and cocci in shape, it grows wonderfully on the MSA plate but did not grow so well on the EMB plate, and it is non-motile. It has a yellow color but I'm just not sure what it is. It was obtained from a public area. Any ideas?

An immersion lens was used to examine the microorganisms microscopically in a light microscope. ANSWER THE QUESTIONS 1. What symbols can be used to identify an immersion lens? What is the immersion system? 3. Why is it necessary to use an immersion lens to study microorganisms? 2.