Comparative analysis of different microbial techniques of quantification applied to anaerobic digestion
In the processes of high microbiological complexity and operating extreme conditions, as thermophilic-dry anaerobic digestion, the application of specific microbiological techniques is the principal tool to accomplish the start-up and control of the equipments. The estimate of microorganisms number in mixed cultivations is very complex, since the diversity of these populations is extreme. Therefore, it is convenient to use several procedures of quantification. DAPI technique is representative of main microbial groups contained in the digester in each organic loading rate studied. While than autofluorescence microscopy technique was not representative of the total methanogenic population or specific. Therefore, the utilisation of a specific technique to determine the methanogens was necessary. FISH technique has allowed to quantify total methanogenic population or specific (H2-utilising methanogens and acetate-utilising methanogens) by ARC915, MB1174 and MX825 probes, respectively.
