Rice paddy soil has been shown to have strong denitrifying activity. However, the microbial populations responsible for the denitrification in various rice paddy soils are not well known. In the present study, key denitrifiers were identified in six rice paddy soils by comparing the bacterial community structures in soils with strong denitrifying activity with those in soils without the activity. The effect of crop rotation on the denitrifier populations was also examined. Our study revealed three notable findings: (1) community structures of total bacteria were similar among the six rice paddy soils with different soil characteristics, (2) the populations that responded to denitrification-inducing conditions differed with soil type (Andosol, Gley soil or Gray lowland soil), (3) the populations that responded to denitrification-inducing conditions were similar within each type of soil, regardless of the cropping system (e.g. continuous or rotation).
Bibliographical noteFunding Information:
We thank Shigeto Sudo and Kazuyuki Yagi (National Institute for Agro-Environmental Sciences), Hiroyuki Mizukami and Noriaki Gunjikake (Kumamoto Prefectural Agricultural Research Center), Yuichiro Furukawa and Yutaka Shiratori (Niigata Agricultural Research Institute) and Masamichi Adachi, Yuichiro Hurukawa, Hiro-shi Saito, Hiroyuki Shiono and Katsuki Kumagai (Yamagata General Agricultural Research Center) for their help in collecting soil samples. This work was supported by the Program for the Promotion of Basic Research Activities for Innovative Biosciences (PRO-BRAIN) from the Bio-oriented Technology Research Advancement Institution, Tokyo, Japan. Additional financial support was provided from a Grand-in-Aid (Soil eDNA) from the Ministry of Agricultural, Forestry and Fisheries of Japan.
- Community structure
- Denaturing gradient gel electrophoresis
- Rice paddy soil