Measurement of bacterial growth

When a few bacteria are inoculated into a liquid growth medium or any solid culture media, the population is counted at intervals. The growth of microbial populations can be measured in several ways. Some methods measure cell numbers; other methods measure the population’s total mass, which is often directly proportional to cell numbers. It is an orderly increase in a cellular constituent. When microorganisms reproduce by binary fission or budding, it also leads to an increase in the number of cells. 

Measurement Of Bacterial Growth

There are several methods for Measurement of bacterial growth to ascertain rates of growth and sampling frames. Because growth leads to an increase in mass and population numbers, this is used to measure growth. Growth can be evaluated using one of the following methods:

• Cell count: This method involves measuring development through either microscopy, an electronic particulate counter, or indirect means by counting colony-forming units.
• In this growth, cell mass can be directly measured by evaluating or by measuring nitrogen concentration in cell lines or indirect means by establishing turbidity with a spectrophotometer.
• Cell activity in this development can be approximated by estimating the level of metabolic activity to population size.         

Methods Of Measuring Microbial Growth

Some standard methods are being used to demonstrate the potential of each type of Measurement. Some of the methods of measuring microbial growth are as follows:

• Direct microscopic count:

Direct counting is perhaps the most effective route for counting microbial numbers. Petroff-hausser counting is a simple and accurate method for counting bacteria. The accumulation of the molecules can be estimated by using the average amount of microbes in these squares.

• Quantification via electronic means

In these ways of assessing microbial growth, a bacterial cell suspension is managed to be kept within an electronic particle counter, and the bacteria are allowed to pass through relatively small orifices. 

• The plate counting technique

This method can be used to calculate the number of molecules that will multiply under particular conditions. Plate counting can indeed be done in two ways: spread plate method or pour plate method. This technique of bacterial counting has been most frequently used for estimating microbial activity in milk, water, foods, and a variety of other materials, with good results.

•  Bacterial number estimation based on turbidity

Turbidity is the only realistic way of monitoring the growth of bacteria in some experiments. When microorganisms grow in a liquid medium, it causes the medium to become turbid or overcast with cells. Turbidity is the condensation or fogginess caused by many unique articles in the form of media or fluid. 

• Nitrogen content determination

Proteins are the primary components of cell material, and nitrogen is a component of proteins. Bacterial nitrogen can be measured in terms of microbial species or cell crops.

•  Cell dry weight determination

The traditional methods of measuring flagellated bacteria and molds are less than ideal. A plate count would not measure this increase in filamentous mass. The number of asexual spores has been primarily considered in plate counts of actinomycetes and molds. It is the most straightforward method for quantitative measurement of bacterial growth & the mass of cells.

• Bacterial Counting Using Filtration

Bacteria are frequently measured by filtration methods when microorganisms are extremely low, such as in ponds or naturally occurring streams. A 100 ml of water threshold is managed to pass through with a thin filter membrane whose nasal passages are too small for bacteria to pass through. 

Factors Affecting Bacterial Growth

Some of the significant factors affecting bacterial growth are as follows:

• · Concentration on nutrition.
• · Temperature.
• · Concentration of gas.
• · pH.
• · Ion concentration and salt concentration
• · Availability of water

Conclusion 

We discussed the Measurement of bacterial growth, factors affecting bacterial growth, quantitative measurement of bacterial growth, and other related topics through the study material notes on Measurement of bacterial growth. We also discussed the methods of measuring microbial growth to give you proper knowledge.

 It is crucial to estimate bacterial growth. Health and environment officers investigate food establishments on a routine basis and collect samples for testing. Water boards inspect water sources regularly. Bacteria grown in fermentation processes are being used to make various products. 

Measuring their progress is an essential part of the process. The optical density at 600 nm, or short OD600, is the most frequently used approach for evaluating bacterial activity in solution. The methodology employs absorption identification mode to determine which part of the light passes throughout a sample, especially a suspension of microorganisms.