Microbiology: Principles and Explorations
9th Edition
ISBN: 9781118743164
Author: Jacquelyn G. Black, Laura J. Black
Publisher: WILEY
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Chapter 6, Problem 21SQ
Summary Introduction
Introduction: Plate count techniques are mainly based on bacterial cell reproduction on the agar plates. It is a traditional method, and it is used for probiotic product quality assurance.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A sample of Earth Alive Soil Activator was diluted by transferring 1 gram into a 9 ml dilution blank (tube A) and then serially diluted five (5) more times by transferring 1 ml of a previous dilution into a tube of 9 ml of sterile water. After making these serial dilutions, 2 ml samples were taken from tubes D, E, and F, added into empty petri dishes, and molten PCA was poured into each petri dish. Tubes A, B, and C were heated in a 80˚C water bath for 30 minutes, 2 ml samples of these tubes were added into empty petri dishes, and molten PCA was poured into each petri dish. These plates were allowed to solidify, and they were incubated at 35˚C for 48 hours. After the incubation period, you counted CFUs on all 6 plates. The results of your CFU counts are contained in table 1.
Table 1. CFU counts for 3 plates from the heated dilutions (A-C) and the 3 plates from the non-heated dilutions (D-F)
# CFUs
Not heated
Heated
A
--
400
B
--
45
C
--
6
D
350
--
E
31
--
F
2
--…
a) What is the dilution factor if you add a 1ml aliquot of a specimen to 99ml of diluent?
b)How to make 500ml of a 1:250 dilution?
In this experiment, a culture was serially diluted to the concentrations below. Each plate was plated with 0.25mL of the dilution. Using the most diluted plate, what is the correct concentration of the original culture?
A) 2.0 X 10^-3 cells/mL
B) 2.0 X 10^5 cells/mL
C) 4.0 X 10^5 cells/mL
D) 5.0 X 10^4 cells/mL
Chapter 6 Solutions
Microbiology: Principles and Explorations
Ch. 6 - What are the differences between the lag phase and...Ch. 6 - How does logarithmic rate of increase differ from...Ch. 6 - Prob. 1.3SCCh. 6 - Why does a direct microscopic count of bacteria...Ch. 6 - What does the ending -phile mean? Distinguish...Ch. 6 - What enzymes do most obligate anaerobes lack? How...Ch. 6 - Prob. 2.3SCCh. 6 - Prob. 3.1SCCh. 6 - Distinguish between the various kinds of media:...Ch. 6 - What is the purpose of a stock culture? Why is it...
Ch. 6 - Prob. 1CCSCh. 6 - Exactly 100 bacteria with a generation time of 30...Ch. 6 - In the above example, do you think that the number...Ch. 6 - Prob. 3CTQCh. 6 - Prob. 1SQCh. 6 - Match the following growth phase terms to their...Ch. 6 - Which of the following is the best definition of...Ch. 6 - Prob. 4SQCh. 6 - The most probable number (MPN) technique is a...Ch. 6 - Match the terms with their definitions:Ch. 6 - Prob. 7SQCh. 6 - Why do foods containing a high concentration of...Ch. 6 - Some bacteria have complex nutritional...Ch. 6 - Prob. 10SQCh. 6 - Which type of cell will shift to aerobic...Ch. 6 - Which of the following statements about endospores...Ch. 6 - Prob. 13SQCh. 6 - Blood agar is often used to observe changes in the...Ch. 6 - A bacterial medium that contains 20 grams of beef...Ch. 6 - MacConkey agar contains the dye, crystal violet,...Ch. 6 - Prob. 17SQCh. 6 - What are the purposes of carrying out the streak...Ch. 6 - Prob. 19SQCh. 6 - During quorum sensing, bacteria sense their...Ch. 6 - Prob. 21SQCh. 6 - Identify the position of each of the following on...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- Andrew has to prepare 30 plates (use maximum volume), 15 slants (small test tube), and 15 stabs (big test tube) of Luria Bertani Agar. a. What is the total volume of the medium needed? b. What is the amount of each component needed, given the following media composition per liter of distilled water:arrow_forwardBlood agar is often used to observe changes in the appear-ance of the agar around the colonies growing on this medium.This medium could then be called:(a) Selective(b) Designated(c) Differential(d) Defined(e) Exactarrow_forwardFor the juice samples in exercise 3-4, you will be using the pour plate technique. In this exercise, you will add juice to a petri dish and pour agar over the sample and mix. Why is the media (potato dextrose agar, PDA) kept in a water bath until you are ready to use it, and why must you work fairly quickly? (One response answers both questions). The media is already solid and will form chunks The media has a dye added to it that must be kept at 45°C until ready to use O PDA is a media that allows growth of many types of fungi, and the heat from the water bath keeps the fungal spores from growing. The media is kept liquid in the water bath with heat, removing the tube from the heat source will cause the PDA to solidifyarrow_forward
- What are the expected problems in the centrifuge in case of imbalance of samples ? *arrow_forwardQuestion 1arrow_forwardYou were instructed to add 1.0 mL out of 4.0 mL of an undiluted sample to 99 mL of sterile diluent. Instead, you add the entire 4.0 mL to the 99 mL. A.) What was your intended dilution factor? B.) What was your actual dilution factor?arrow_forward
- - What is a pure culture? - Describe the procedure for making a streak plate from a clinical specimen (like a urine culture). - What is the desired outcome (result) of a streak plate? - Clinically, why is it important to make a pure culture from a clinical specimen? What do you do next in order to treat the patient?arrow_forwardA culture of E. coli is diluted as follows:(1) 65mL are added to 435mL of water.(2) 10uL from (1) are then added to 9.99mL of water.(3) A 10-3 dilution is made from tube # (2).(4) 100uL from (3) are plated for a pour plate and incubated. There were 34 colonies counted on one quarter of the plate following incubation. a) What was the overall dilution?b) How many cfu/mL were present in the original culture?c) How many milliliters of water is needed to make a 10-3 dilution using 1000 uL from the original culture?arrow_forwardYou have found that the D-value (decimal reduction value) of an antimicrobial agent to be 4 minutes when the agent was exposed to a bacterial culture having an initial total viable cel1 count of 10° CFU/mL. After 4 minutes upon addition of the antimicrobial agent, what would have been the total viable count of the culture in this experiment? A) O 10° CFU/mL B) O 10$ CFU/mL C) O 10° CFU/mL D) O 10' CFU/mLarrow_forward
- What are the advantages and disadvantages of the filter method in the analysis of water samples? Why is the incubation temperature critical for this test?arrow_forwardEthanol has been carried over into your DNA sample (two answers possible here, select both of them) a) The column tip touched the column flow through b) The cells stayed in the lysis buffer for too long c) You didn't add enough wash buffer d) You did not centrifuge a final time after the final washarrow_forwardI am not sure how to go about illustrating and answering this question: Use a diagram to illustrate how 10^-4, 10^-6 and 10^-8 dilutions in water of the soil suspension in a final volume of 10 mL will be prepared. There are only three tubes available.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles Of Radiographic Imaging: An Art And A ...Health & NutritionISBN:9781337711067Author:Richard R. Carlton, Arlene M. Adler, Vesna BalacPublisher:Cengage Learning
Principles Of Radiographic Imaging: An Art And A ...
Health & Nutrition
ISBN:9781337711067
Author:Richard R. Carlton, Arlene M. Adler, Vesna Balac
Publisher:Cengage Learning