title: Analysis of ammonia monooxygenase and archaeal 16S rRNA gene fragments in nitrifying acid-sulfate soil microcosms.
abstract: The present study describes the occurrence of a unique archaeal ammonia monooxygenase alpha subunit (amoA) gene in nitrifying acid-sulfate soil microcosms at pH 3.5. The soil was collected from an abandoned paddy field in Thailand. Microcosms were incubated in the dark at 30°C for 372 days with the following three treatments: addition of ammonium sulfate solution once a month (I) or once a week (II), and addition of only sterilized water (III). A quantitative PCR analysis revealed an increase in abundance of the archaeal amoA gene in microcosm soils in which nitrate concentrations increased after incubation. A phylogenetic analysis indicated a predominance of the novel gene, and a predominance of a betaproteobacterial amoA gene affiliated with the genus Nitrosospira. A 16S rRNA gene-based PCR assay revealed that crenarchaeotic Group I.1d was predominant among the Crenarchaeota in microcosms. These results suggest the presence of ammonia-oxidizing archaea corresponding to the unique amoA lineage in nitrifying acid-sulfate soil microcosms at pH 3.5.
authors.affiliation: Graduate School of Bioresource Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-8510, Japan.
authors.forename: Asami
authors.initials: A
authors.lastname: Nakaya
authors.forename: Yuki
authors.initials: Y
authors.lastname: Onodera
authors.forename: Tatsunori
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Satoh
authors.forename: Reiji
authors.initials: R
authors.lastname: Takahashi
authors.forename: Satohiko
authors.initials: S
authors.lastname: Sasaki
authors.forename: Tatsuaki
authors.initials: T
authors.lastname: Tokuyama