Abstract
Bacterial communities of activated sludge were analyzed monthly for one year by using FISH method with 33 kinds of genus specific probes. These obtained FISH data were also analyzed with cluster analysis. Activated sludge were taken from 9 trains in 5 sewage treatment plants in Japan. These were classified into following 5 treatment processes; Conventional activated sludge process, Oxidation Ditch process, Pre-Denitrification process, Anaerobic-Anoxic-Oxic process and Modified Bardenpho process. As the results, following things were found. When the bacterial communities were compared with 9 trains, it was suggested that these were different from each other. The occupation ratios of genus Nitrospira and genus Ethanoligenens were observed as the highest group in many trains. In the same sewage treatment plant, it was suggested that the bacterial communities obtained from different treatment trains were similar to each other. In all of 4 treatment processes of K plant, the occupation ratio of phylum proteobacteria and nitrogen removal bacteria were higher than other kinds of bacteria. In conventional process and oxidation ditch process, the occupation ratio of phylum Bacteroidetes were higher than other bacterial groups. In Pre-Denitrification process, A2O process and Modified Bardenpho process, the occupation ratio of phylum Proteobacteria were higher than other bacterial groups.According to comparison of classification of treatment processes, it was suggested that a high / low of phosphate removing bacteria affected on the bacterial communities.In these results, it was indicated that the possibility that bacterial community can be used as an index of activated sludge.
