Use of the indirect immunofluorescence test for assaying anaerobic microbial communities

A method to assay eu- and archebacteria using the indirect immunofluorescence test (IIFT) is proposed. Various cell count methods are compared. The size of microbial populations determined by using IIFT in the process of growth adequately reflects the microbial number obtained by conventional microbiological methods. The bacteria were shown to retain their antigenic abilities throughout growth. Using the anaerobic cellulolytic thermophilic community, it was demonstrated that, having a certain bank of immune sera, IIFT allows not only the qualitative immunotype composition of a mixed population to be investigated but also the number of cells of each immunotype and their share in the population to be determined. This may prove useful in operation of bioreactors to monitor the processes as well as in assessing the anaerobe abundance in natural ecosystems.