Bacterial communities in iron mottles in the plow pan layer in a Japanese rice field: Estimation using PCR-DGGE and sequencing analyses

Bacterial communities in iron (Fe) mottles in the plow pan layer in a Japanese rice field were estimated using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis targeting 16S rDNA genes. The DGGE band patterns indicate that distinct bacterial communities with lower diversity inhabit Fe mottles compared with the reference soil matrix. Many of the DGGE bands of the Fe mottles that were sequenced (12 of 29 DGGE bands) were closely related to bacteria involved with Fe oxidation and reduction: Siderooxidans ghiorsii, Azoarcus sp., Azovibrio sp., Dechloromonas sp., Acidimicrobium ferrooxidans, Geobacter psychrophilus, Clostridium sp., Desulfovibrio sp. and Desulfonatronum cooperativum. The results suggest that specific bacteria inhabit Fe mottles and may play a role in the Fe cycle.