AUTHOR=Jing Hongmei , Cheung Shunyan , Xia Xiaomin , Suzuki Koji , Nishioka Jun , Liu Hongbin 

TITLE=Geographic Distribution of Ammonia-Oxidizing Archaea along the Kuril Islands in the Western Subarctic Pacific

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 8 - 2017

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.01247

DOI=10.3389/fmicb.2017.01247

ISSN=1664-302X

ABSTRACT=Niche differentiation of the ammonia-oxidizing archaea (AOA) from the surface photic zone to the deep bathypelagic waters in the western subarctic Pacific adjacent to the Kuril Islands was investigated using pyrosequencing based on the ammonia monooxygenase subunit A (amoA) gene. Genotypes of clusters A and B dominated in the upper euphotic zone and the deep waters, respectively. Quantitative PCR assays revealed that the occurrence and ammonia-oxidizing activity of AOA reached their maxima at the depth of 200 m, where a higher diversity and abundance of active AOA was observed at the station located in the marginal sea exposed to more terrestrial input. This highlights the necessity to apply the gene transcript for the investigation of functional microbial assemblages involved in the biogeochemical cycles. Similar community composition of AOA observed at the two stations adjacent to the Kuril Islands maybe due to water exchange across the Bussol Strait. They distinct from the station located in the western subarctic gyre, where sub-cluster WCAII had a specific distribution in the surface water, and this sub-cluster seemed having a confined distribution in the western Pacific. The effect of the Kuril Islands on the phylogenetic composition of AOA between the Sea of Okhotsk and the western subarctic Pacific is not obvious, possible because our sampling stations are near to the Bussol Strait, the main gateway through which water is exchanged between the Sea of Okhotsk and the Pacific. The clear vertical distribution profile of AOA communities and niche separation among stations along the Kuril Islands were essentially determined by the in situ prevailing physicochemical gradients along the two dimensions.