I don't understood what you exactly mean by the qualitative bacterial growth, but sure there are methods which could be employed to find the abundance of the target group of microorganisms. And abundance is already a quantitative term, nevertheless a relative expression but serves the purpose.

Your question is too broad in terms of purpose, please specify something specific to get better answers. What is your purpose and what techniques you could use ?

https://www.hindawi.com/journals/ijmicro/2017/5291283/

Re: Abhijeet Singh

Apologies for the confusing question. instead of qualitative, what i meant is quantitative.

i would like to investigate anaerobic bacteria grown in collective count, not into specific community by means of culturing.

while the performance of AD system is easy to evaluate with its terminal products and intermediaries products, however, when new chemical catalyst is applied, it is difficult to relate effect of catalyst and bacteria growth. That's why i would like to measure all community of bacteria found in Anaerobic digestion in quantitative representation e.g #bacteria count/ml

do you have further suggestion please?

thanks Sir.

If you want to find the total bacterial population in an anaerobic digestion, please read some articles related to the Next-generation Sequencing tecnology and particularly Illumina 16S rRNA gene sequencing. It could be used for separate analysis of bacteria and archaea using specific primers or combined using universal primers. There are a lot of good papers and tutorials available over the internet. Another thing i would like to measure the result of this analysis would not be according to the bacterial_count/ml, but the results will be according to the relative abundance in whole sample.

You can combined this analysis with the qPCR analysis to get more information about the absolute abundance of any target and by using some math and statistics calculate the bacterial count in per ml sample and similarly bacterial_count in total volume in your desired volume.

Re: Hamit Can

Sir, thank you so much for your advice

in fact i am also planning to use DNA Extraction, and Sequencing in PCR. there comes the hurdle that is the cost. at the moment, i am setting up comparative reactors ( about 6) and monitoring their performance. the cost and time taken for daily sampling to DNA Extraction, and Sequencing is economically un-viable.

thanks for your contribution.