Community and functional shifts in ammonia oxidizers across terrestrial and marine (soil/sediment) boundaries in two coastal Bay ecosystems

• Published in: Environmental microbiology Vol. 20; no. 8; pp. 2834 - 2853
• Main Authors: Zhang, Li‐Mei, Duff, Aoife M., Smith, Cindy J.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.08.2018
• Subjects: Ammonia; AmoA gene; Aquatic soils; Archaea; Bacteria; Biogeochemistry; Boundaries; Coastal environments; Communities; Community composition; Community structure; Composition; denaturing gradient gel electrophoresis; Deoxyribonucleic acid; DNA; ecological differentiation; Ecosystems; Field tests; Gene sequencing; genes; Marine ecosystems; Niches; Nitrification; nitrogen; oxidants; Oxidation; Oxidizing agents; pH effects; quantitative polymerase chain reaction; salinity; Sediment; Sediments; Soil; Soil structure; Soils; Transcription; transcription (genetics)
• DOI: 10.1111/1462-2920.14238
• ISSN: 1462-2912; 1462-2920

Summary Terrestrial–marine boundaries are significant sites of biogeochemical activity with delineated gradients from land to sea. While niche differentiation of ammonia‐oxidizing archaea (AOA) and bacteria (AOB) driven by pH and nitrogen is well known, the patterns and environmental drivers of AOA and AOB community structure and activity across soil‐sediment boundaries have not yet been determined. In this study, nitrification potential rate, community composition and transcriptional activity of AOA and AOB in soil, soil/sediment interface and sediments of two coastal Bays were characterized using a combination of field investigations and microcosm incubations. At DNA level, amoA gene abundances of AOA were significantly greater than AOB in soil, while in sediments AOB were significantly more abundant than AOA, but at the soil/sediment interface there were equal numbers of AOA and AOB amoA genes. Microcosm incubations provided further evidence, through qPCR and DGGE‐sequencing analysis of amoA transcripts, that AOA were active in soil, AOB in sediment and both AOA and AOB were active at the soil/sediment interface. The AOA and AOB community composition shifted across the coastal soil‐interface‐sediment gradient with salinity and pH identified as major environmental drivers.