高温接触酸化型トイレ実証試験における処理槽内の細菌群集構造解析

抄録

The bacterial community structure in composting toilet reactors was analyzed using three molecular biological techniques (PCR-DGGE, T-RFLP and cloning). Investigation was conducted for about six months at two trial sites in Japan. The main points of difference between the two sites are in the frequency of use air temperature (Site1: 5-6 times·d^-1, 14.9°C, Site2: 30 times·d^-1, 23.4°C). The DGGE band pattern indicated that the bacterial community profiles changed immediately after the start of the operation and did not reach a stable phase. Sequencing of the dominant DGGE band and clones revealed that the members of the community consisted of Bacteroidetes-related, Proteobacteria-related and other uncultured bacteria in the Site1 reactor. In contrast, Bacillus-related bacteria were detected from dominant DGGE bands from samples in Site2. This difference resulted from the difference in temperature inside the reactors. Some sequences from Site2 samples were also reported from other biodegradation processes under aerobic and thermophilic conditions. The bacterial community of the Site1 profile also had some similarity to other composting processes. Further investigation into the details of the bacterial community and the metabolic characteristics is needed to improve composting toilet operation.