A Metagenome-Based Investigation of Gene Relationships for Non-Substrate-Associated Microbial Phosphorus Cycling in the Water Column of Streams and Rivers

• Published in: Microbial ecology 2018-11, Vol.76 (4), p.856-865
• Main Authors: LeBrun, Erick S., King, Ryan S., Back, Jeffrey A., Kang, Sanghoon
• Format: Article
• Language: English
• Subjects: Anthropogenic factors; Archaea - genetics; Archaea - metabolism; Arkansas; Bacteria - genetics; Bacteria - metabolism; Bioavailability; Biogeochemical cycle; Biogeochemical cycles; Biogeochemistry; Biomedical and Life Sciences; Composition; Correlation; Creeks & streams; Ecology; Eutrophication; Genes; Genes, Archaeal - genetics; Genes, Bacterial; Genomics; Geoecology/Natural Processes; Life Sciences; Metagenome; Metagenomics; Microbial Ecology; Microbiology; MICROBIOLOGY OF AQUATIC SYSTEMS; Microorganisms; Mineral nutrients; Nature Conservation; Nutrient cycles; Oklahoma; Orthophosphate; Phosphorus; Phosphorus - metabolism; Rivers; Rivers - microbiology; Streams; Substrates; Trophic levels; Water column; Water Pollutants, Chemical - metabolism; Water Quality/Water Pollution
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/s00248-018-1178-0

Phosphorus (P) is a nutrient of primary importance in all living systems, and it is especially important in streams and rivers which are sensitive to anthropogenic P inputs and eutrophication. Microbes are accepted as the primary mineralizers and solubilizers of P improving bioavailability for organisms at all trophic levels. Here, we use a genomics approach with metagenome sequencing of 24 temperate streams and rivers representing a total P (TP) gradient to identify relationships between functional genes, functional gene groupings, P, and organisms within the P biogeochemical cycle. Combining information from network analyses, functional groupings, and system P levels, we have constructed a System Relational Overview of Gene Groupings (SROGG) which is a cohesive system level representation of P cycle gene and nutrient relationships. Using SROGG analysis in concert with other statistical approaches, we found that the compositional makeup of P cycle genes is strongly correlated to environmental P whereas absolute abundance of P genes shows no significant correlation to environmental P. We also found orthophosphate (PO₄³⁻) to be the dominant factor correlating with system P cycle gene composition with little evidence of a strong organic phosphorous correlation present even in more oligotrophic streams.