PCR-DGGE法による嫌気好気汚泥の微生物群集解析

抄録

Due to an increased eutrophication of rivers and lakes, enhanced biological phosphorus removal (EBPR) process is now taken notice of. But the strategy of controlling EBPR process has not been established yet, because it is sometimes observed that the sludge suddenly loses the phosphorus removal activity. This is mainly because the bacteria which accumulate polyphosphate in the EBPR sludge have not been isolated, and because there is not enough information about the whole bacterial community in EBPR sludge.
Nowadays, new methods for analyzing microbial community such as molecular methods become available. In this study, the microbial community of EBPR sludge were characterized using the PCRDGGE (Polymerase chain reaction-Denaturing gradient gel electrophoresis) method.
Laboratory-scale sequencing batch reactor (SBR) was used, and the polyphosphate accumulating organisms (PAOs) were enriched using anaerobic aerobic configuration. The simple substrate which contained only acetate as a carbon source was fed. The microbial community was monitored usingthe PCR-DGGE method for about 2 months after the seed sludge was inoculated. The community gradually changed and got simple about lmonth later. The major bands on the DGGE gel were excised and the DNA recovered from them was sequenced. As a result, the bacteria that continued to increase during enrichment and became dominant at last were closely related to one of the putative PAO group which Crocetti et al.(2000) and Hesselmann et al (1999) have proposed. This PAO group is closely related to Rhodocyclus group (α Proteobacteria), but has no photosynthetic activity.