Loading...

Messages

Proposals

Stuck in your homework and missing deadline? Get urgent help in $10/Page with 24 hours deadline

Get Urgent Writing Help In Your Essays, Assignments, Homeworks, Dissertation, Thesis Or Coursework & Achieve A+ Grades.

Privacy Guaranteed - 100% Plagiarism Free Writing - Free Turnitin Report - Professional And Experienced Writers - 24/7 Online Support

What is pour plate method in microbiology

26/10/2021 Client: muhammad11 Deadline: 2 Day

2420-Lab 6- Pure Culture, Bacterial Enumeration
Directions:
Answer following questions after reading the information and watching the video from the link below. Use color RED or BLUE for your answers. Submit the completed document on eCampus for grading. Refer to

· the textbook chapter 4 (sections 4.3 and 4.7) (Nester- McGraw Hill)

· Lab Manual by Dr. Su, pages 45-50 (optional)

· Link: Cultivation of Bacteria-Streak plate, Virtual Edge Experiment- 3A

Cultivation of bacteria in the laboratory- Streak plate
Read the information from textbook from chapter 4 review sections 4.3 (pages 96-97)) to answer the following questions.

Pure Culture
1. What is a pure culture?

This is the population of multicellular organisms or cells that grow in the absence of other species or types. They originate from one cell or a single organism, in this case the cells are the genetic clones of each other.

2. What is the need for a pure culture of bacteria?

It facilitates the application of recombinant DNA technology through the isolation of clones. Pure culture tends to react differently in isolation as opposed to when it is combined with other species.

3. How many bacteria are required to start a colony?

One bacterium

Streak Plate Method:
Links: Triple streak, Quadrant Streak

4. What is the purpose of sterilizing the loop in between streaks in this method?

Sterilization dilutes out the sample placed in the initial region of the agar surface.

5. Is this method useful for quantifying bacterial cells in the original culture? Yes Or No- explain your answer:

Yes, the method can be used in quantifying the cells in a culture through plating a known volume of the cell culture on a petri dish with a growth medium.

6. Study the picture below: Which step showed isolated colonies and why?

Isolated colonies are formed once the lone bacterial cells divide and form thousands of new bacterial cells after media inoculation.

Identification of Bacteria - ppt download

7. The picture from question number 7 shows 3 types bacterial species appearing on red, white and yellow colonies. What does this tell you about the original culture?

Colony morphology is a unique way of identifying bacteria.

Pour Plate and Spread Plate methods
Both these methods are “quantitative” meaning you can find out how many bacterial cells you are working with.

· Watch this video as well: Serial Dilution

· Results: Notice how colonies are counted, why are some colonies embedded in the agar in the pour plate method.

· Link: Enumeration of Bacteria, Virtual Edge Experiment- 7B and the textbook chapter 4 (sections 4.5 and 4.6) (Nester- McGraw Hill) to answer the following questions:

· The video in the above link shows “Spread Plate” technique which makes used of agar plates to spread the diluted samples.

· In the Pour Plate technique, liquefied agar cooled to 45-50oC is used instead of a ready agar plate.

8. What is the difference in the spread plate and pour plate method?

In pour plate a known volume of the sample is mixed with agar and poured into a plate while in spread plate a known volume of the sample is spread on the surface of the agar medium.

9. Which of the two methods, spread plate and pour plate has better separation of bacterial colonies?

Pour plate method

10. Why is it necessary to cool down agar to 45-50oC?

To prevent condensation from forming on the lid. It ensures the bacteria does not die when being transferred to the agar and to ensure the agar does not solid.

11. Give two scenarios where the number of bacterial cells may be important.

Persister cells are medically important. The milk-souring bacterial genus lactobacillus in making yoghurt.

12. What is CFU?

This is a colony forming unit used to estimate the number of viable bacteria or fungal cells within a sample.

Serial dilutions are done as shown in the picture below:
4: Dilution Worksheet and Problems - Biology LibreTexts

Sample CFU problems:
One ml of a bacterial culture was pipetted into a 9 ml dilution blank. One-tenth ml of this dilution was pipetted into a 9.9 ml dilution blank. From this dilution, one-tenth ml was plated with 25 ml of culture medium. 220 colonies arose after incubation. How many colony-forming units were present per ml of the original culture?

http://www.jlindquist.net/generalmicro/DTimages/ps1a.jpg

Working through the problem with the formulas:
Formula-1: dilution made X amount inoculated = "plated dilution"

1/10 X 1/100 X 1/10 = 1/10,000 or 10–4

Formula-2: dilution factor X number of colonies = number of CFUs/ml

104 X 220 = 2.2 X 106

As we understand the so-called "plated dilution" to represent the actual amount of undiluted sample being tested, we can look at the problem (and similar problems) like this: If 220 colonies arose from plating (the equivalent of) 10–4 ml of the culture, then (proportionally) there would have been 220 X 104 which is same as 2.2 X 106 CFUs per one ml of the original, undiluted culture . This is the reasoning behind the second of the two dilution formulas.

The dilution factor is the inverse of the plated dilution and is meant to inflate the colony count to give the number of CFUs that were in one ml of the original, undiluted sample at the time it was plated out.

Now solve problems 13-14
13. Ten ml of spring water were added to a petri dish to which 40 ml of melted Plate Count Agar were added. After incubation, 35 colonies arose on the plate. What was the count of CFUs per ml of the spring water?

The dilution facor is 10-1. The plated solution represents that actual amount of sample being tested i.e. 10 ml. the inverse of the plated dilution i.e. dilution factor would be 10-1

14. You have obtained a pond water sample and wish to determine the concentration of bacteria which are gram-negative and lactose-fermenting. After making two 1/100 dilutions, you plate 0.1 ml of the second dilution onto each of two plates of MacConkey Agar. After appropriate incubation, you find that one plate contains 155 red colonies and 45 white colonies, and the other plate contains 160 red colonies and 35 white colonies. What was the concentration of gram-negative, lactose-fermenting CFUs per ml of the pond water sample?

Only gram-negative bacteria should grow on MacConkey agar. The red colonies are lactose-fermenters. The average number of colonies of lactose-fermenting gram-negative bacteria is 157.5.

dilutions made X amount inoculated = "plated dilution"

1/100 X 1/100 X 1/10 = 1/105 or 10–5

dilution factor X no. colonies = no. CFUs/ml

105 X 157.5 = 1.6 X 107

Homework is Completed By:

Writer Writer Name Amount Client Comments & Rating
Instant Homework Helper

ONLINE

Instant Homework Helper

$36

She helped me in last minute in a very reasonable price. She is a lifesaver, I got A+ grade in my homework, I will surely hire her again for my next assignments, Thumbs Up!

Order & Get This Solution Within 3 Hours in $25/Page

Custom Original Solution And Get A+ Grades

  • 100% Plagiarism Free
  • Proper APA/MLA/Harvard Referencing
  • Delivery in 3 Hours After Placing Order
  • Free Turnitin Report
  • Unlimited Revisions
  • Privacy Guaranteed

Order & Get This Solution Within 6 Hours in $20/Page

Custom Original Solution And Get A+ Grades

  • 100% Plagiarism Free
  • Proper APA/MLA/Harvard Referencing
  • Delivery in 6 Hours After Placing Order
  • Free Turnitin Report
  • Unlimited Revisions
  • Privacy Guaranteed

Order & Get This Solution Within 12 Hours in $15/Page

Custom Original Solution And Get A+ Grades

  • 100% Plagiarism Free
  • Proper APA/MLA/Harvard Referencing
  • Delivery in 12 Hours After Placing Order
  • Free Turnitin Report
  • Unlimited Revisions
  • Privacy Guaranteed

6 writers have sent their proposals to do this homework:

Top Rated Expert
Exam Attempter
Top Academic Guru
Phd Writer
Essay Writing Help
Quick Finance Master
Writer Writer Name Offer Chat
Top Rated Expert

ONLINE

Top Rated Expert

I am an academic and research writer with having an MBA degree in business and finance. I have written many business reports on several topics and am well aware of all academic referencing styles.

$47 Chat With Writer
Exam Attempter

ONLINE

Exam Attempter

I have read your project details and I can provide you QUALITY WORK within your given timeline and budget.

$19 Chat With Writer
Top Academic Guru

ONLINE

Top Academic Guru

I am a professional and experienced writer and I have written research reports, proposals, essays, thesis and dissertations on a variety of topics.

$21 Chat With Writer
Phd Writer

ONLINE

Phd Writer

This project is my strength and I can fulfill your requirements properly within your given deadline. I always give plagiarism-free work to my clients at very competitive prices.

$47 Chat With Writer
Essay Writing Help

ONLINE

Essay Writing Help

I reckon that I can perfectly carry this project for you! I am a research writer and have been writing academic papers, business reports, plans, literature review, reports and others for the past 1 decade.

$23 Chat With Writer
Quick Finance Master

ONLINE

Quick Finance Master

I have written research reports, assignments, thesis, research proposals, and dissertations for different level students and on different subjects.

$50 Chat With Writer

Let our expert academic writers to help you in achieving a+ grades in your homework, assignment, quiz or exam.

Similar Homework Questions

Bethesda mining company answers - Ancient egypt research project - For anyone - Agilent 7890b gc price - Biology - Newspaper clipping that shows the use of statistics - What are the 7 domains of a typical it infrastructure - Bubble tea consumption statistics singapore - The mask you live in discussion questions - Case - Trinity beach driving school - Navman tracker 5500 c map cards - The edible woman summary - Timeline language development - Why america is self segregating - Starbucks password reset unsuccessful - Global variables in labview - What does non discriminatory use of language mean - 2pave paler due by Sunday on early Muslim Society including the roles of women based on the surah readings . - Dare scheme leaving cert - The greatest journey pdf - Chapter summary - Advantages of correlational research in psychology - Risk Analysis Formula - Lin corporation has a single - Hi - Slender shapes by teez her - Should college students be able to carry guns on campus - Slow and slimy mover crossword - Nat translation table example - The exodus people crossword - Science fair display board - Roe valley integrated primary school - Smoke wizard century 3 mall - Philosophy of leadership the power of authority - Sherman alexie indian education answers - Which of the following industries can be least described as a slow-cycle market? - 007d6 - Organizational behaviour topics for presentation - Introduction to project management kathy schwalbe 5th edition pdf - Case Study - On her loving two equally - External Factor Evaluation (EFE) and Competitive Profile Matrix (CPM) - Secluded private open space definition victoria - Memento anterograde amnesia - Dare to dream performance horses - British gas standby saver manual - Forex wave theory pdf - Mpeg lossy or lossless - Example of argumentative essay about education - Gold coast city council office - The federalist paper number 10 worksheet answers - Discuss in 500 words or more the differences between and advantages of MAC, DAC, and RBAC. - Mean median mode multiple choice doc - Mays and mccovey are beer brewing companies - Eyewitness Identification Writing Assignment - Week 8 capstone care plan part 3 - 1.3 9 practice complete your assignment - 14 philippine national heroes - Longest river in north carolina - Earth cookie creations - Turning technologies clicker id - Minn kota riptide manual - Volume exercises for grade 7 - Geometry chapter 2 test answers - Pay for Performance (P4P) - Hermione foster wellcome trust - Simplify the fraction 10 20 - Quartered safe out here sparknotes - Jaandar meaning in english - Tricking and tripping analysis - Wakefield coroner's court parking - Monash tone of voice - Week 7 - Short Essays - Reading habits survey questions - PSYC Life Span Development Psychology - Zappos is a weird company - Three parts of hamilton's financial plan - Crisis management - When redesigning the ejection seat, which probability is more relevant? - Miniclip word search games - Winappls - 515 week2group - Secondary school teacher personal statement examples - Group processes an introduction to group dynamics by joseph luft - Pgcc human resources - Week 10 Discussion - Individuality map the giver - Line follower robot design - Buddhist temple visit essay - Today poem by billy collins - Zen Buddhism 4 - Epicurus reader pdf - Initial consonant deletion apraxia - PICOT Question Paper - Red black tree python - Power point - St edmund hall notable alumni - 600 words statistics math questions. Due in 3hrs. Statistics for Nursing Research - MGT351 week 5