Why are the surface colonies on a pour plate larger than those within the medium?

Why are the surface colonies on a pour plate larger than those within the medium? More room to grow on the surface than in the agar. Toxic by-products dilute out on the surface better. More nutrients available on surface as the bacteria grows.

1. How do the colonies on the surface of the pour plate differ from those suspended in the agar?
2. What is different about the colony growth on pour plates when compared with spread plates?
3. What is the advantage of the pour plate method over the other methods of bacteria colony isolation What are some problems?
4. Why do colonies grow in pour plates?
5. Why is pour plate method more accurate?
6. Why is streak plate better than pour plate?
7. How do the results of the pour plate method compare?
8. Which are advantages of the quadrant streak plate method when compared to the pour plate method?
9. What is the difference between surface and subsurface colonies in a pour plate?
10. What is the purpose of spread plate method?
11. Where do colonies grow in pour plates?
12. What is pour plate?
13. What is the principle of pour plate method?
14. What factors make the pour plate method selective?
15. What is the disadvantage of the streak plate technique of the pour plate technique?

How do the colonies on the surface of the pour plate differ from those suspended in the agar?

How do colonies on the surface of a pour plate differ from those suspended in the agar? If they're on the surface they are obligate aerobes- microaerophiles. If in liquid, they are obligate anaerobes -aerotolerant anaerobes. How would you determine whether a colony was a contaminant on a streak plate?

What is different about the colony growth on pour plates when compared with spread plates?

Generally, pour plates is the method for counting the number of colony-forming bacteria present in a liquid specimen. Pour plates also allow the identification of bacteria as aerobes, anaerobes or facultative aerobes. On the other hand, spread plates allow the isolation of specific clonal colonies.

What is the advantage of the pour plate method over the other methods of bacteria colony isolation What are some problems?

The pour plate technique can be used to determine the number of microbes/mL in a specimen. It has the advantage of not requiring previously prepared plates, and is often used to assay bacterial contamination of food stuffs.

Why do colonies grow in pour plates?

Pour-plate Technique.

With the pour-plate technique, the colonies form within the agar as well as on the surface of the agar medium thus providing a convenient means to count the number of viable cells in a sample. This procedure is used in a variety of industrial applications.

Why is pour plate method more accurate?

Advantages of Pour Plate Technique

Will detect lower concentrations than surface spread method because of the larger sample volume. It requires no pre-drying of the agar surface. The most common method for determining the total viable count is the pour-plate method.

Why is streak plate better than pour plate?

Advantages. Moreover, streak plate is important for the isolation of bacterial cultures by preparing distinct colonies while the pour plate is important for the quantification of colonies in a solid medium.

How do the results of the pour plate method compare?

How do the results of the pour-plate method compare with those obtained using the streak-plate and spread-plate methods? The results should compare favorably with the streak plate and spread plate methods to obtain isolated colonies. The bacteria samples are diluted several times to ensure decrease # of microbes.

Which are advantages of the quadrant streak plate method when compared to the pour plate method?

What advantage(s) does the streak-plate method have over the pour-plate method? The streak-plate method is more economical in materials and time.

What is the difference between surface and subsurface colonies in a pour plate?

Subsurface colonies are small and embedded in the agar. They do not have the identifying characteristics of surface colonies such as edge, surface characteristics, and in some cases, pigment. Subsurface colonies must grow under limited oxygen conditions, which would affect growth and some characteristics.

What is the purpose of spread plate method?

The spread plate method is a technique to plate a liquid sample containing bacteria so that the bacteria are easy to count and isolate. A successful spread plate will have a countable number of isolated bacterial colonies evenly distributed on the plate.

Where do colonies grow in pour plates?

Pour plates allow micro-organisms to grow both on the surface and within the medium. Most of the colonies grow within the medium and are small in size and may be confluent. The few colonies that grow on the surface are of the same size and appearance as those on a streak plate.

What is pour plate?

Definition of pour plate

: a plate prepared by mixing the inoculum with the cooled but still fluid medium before pouring the latter into the petri dish.

What is the principle of pour plate method?

Principle of Pour Plate Method

In this Method, serial dilutions of the inoculum (serially diluting the primary specimen) are added within sterile Petri plates to which is poured melted and cooled (42-45°C) agar medium and completely mixed by revolving the plates which are then left to solidify.

What factors make the pour plate method selective?

Since the warm, molten agar is poured onto the bacterial suspension, the temperature could damage or kill the heat- sensitive bacteria. Thus, pour plate method is considered as selective.

What is the disadvantage of the streak plate technique of the pour plate technique?

What is a disadvantage of the streak plate technique? What is a disadvantage of the pour plate technique? Sometimes bacteria will clump together and look like a colony when they are not.