GUESSING THE NUMBER OF MICROORGANISMS DURING THE FERMENTATION PROCESS

One of the most important parameters monitored during a fermentation process is determining the number or concentration of microorganisms .The problem is microorganisms as bacteria are too small to be seen with our naked eyes. In the case of fungal fermentations, it is difficult to differentiate the whole organism as a hyphae or unit cells

There are many methods of counting microorganisms, both direct and indirect methods. All the methods have its advantages and limitations.

In most fermentation studies it is most crucial that a very rapid method of establishing the number or concentration of microorganisms be carried out immediately. It is of no point during the fermentation process to know or estimate the number of microorganisms days later when the fermentation process has completed

The most simplest methods is of course using dry weight or the biomass which gives the amount of microorganisms in terms of total biomass weight. A simple calibration curve is made with optical density versus dry weight of microorganisms are plotted out. Once the calibration curve is made it is only a matter of determining the optical density of the sample using spectrometer to know the equivalent value of biomass concentrations

There are other methods of estimating the number of microorganisms using advanced fluorescent and even DNA methods. The price could be a factor to consider...