لخّصلي

Microbial growth measurement

Microbial growth (increase in the number of cells formed as a result of division) can be estimated in several ways:

1.You can follow one of the following methods:

A- Estimation of the total number of cells:

This count is done directly under the microscope in colored preparations.A known volume of the microbial culture or suspension (0.01 ml) is spread evenly over a known area of a glass slide

The resulting membrane is fixed and colored, then the individual microbes are counted by examining it under the microscope field.The number of cells in (1 ml) of the suspension is calculated.- Estimation of the total number of cells cont.,

o Special plates (as Petroff hausser, hemocytometer) are used, which have a counting chamber that helps to carry out the count accurately and quickly without coloring.or indirectly depending on the degree of medium turbidity.2.3.

Microbial growth measurement

Microbial growth (increase in the number of cells formed as a result of division) can be estimated in several ways:

1. Measurement of the total number of microbial cells: directly using a microscope, or

indirectly by colony counting.

2. Measurement cell mass:

directly by estimating the increase in dry or wet weight, or through one of the elements of the cellular contents(C,N). or indirectly depending on the degree of medium turbidity.

3. Measurement of cellular activity, which is an indirect method based on comparing enzymatic activity, the output is the amount of growth to be measured.

You can follow one of the following methods:

A- Estimation of the total number of cells:

This count is done directly under the microscope in colored preparations.

A known volume of the microbial culture or suspension (0.01 ml) is spread evenly over a known area of a glass slide

The resulting membrane is fixed and colored, then the individual microbes are counted by examining it under the microscope field.

The number of cells in (1 ml) of the suspension is calculated.- Estimation of the total number of cells cont.,

• Special plates (as Petroff hausser, hemocytometer) are used, which have a counting chamber that helps to carry out the count accurately and quickly without coloring.

• The disadvantages of this method are that it gives the total number of living and dead cells, and that it is not sufficient in the case of very dilute suspensions.