title: Biogenic phosphorus compounds in sediment and suspended particles in a shallow eutrophic lake: a ³¹P-nuclear magnetic resonance (³¹P NMR) study.
abstract: Differences in biogenic phosphorus (P) compounds between sediment and suspended particles in aquatic environments are important for understanding the mechanisms of internal P loading, but these differences are still unknown. We used solution-state (31)P-nuclear magnetic resonance spectroscopy ((31)P NMR) with NaOH-ethylenediaminetetraacetic extraction to detect the multiple P compounds in suspended particles and sediment in the eutrophic Lake Kasumigaura, including orthophosphate monoesters, orthophosphate diesters, pyrophosphate, and polyphosphate. We tested the hypothesis that there is a significant difference between these groups in suspended particles and sediment. Biogenic P other than orthophosphate was found in significantly higher proportions in suspended particles (74.3% of total P) than in sediment (25.6%). Orthophosphate monoesters were comparatively more abundant in suspended particles, as indicated by the ratio of orthophosphate diesters to monoesters (average, 0.31 for suspended particles; 1.05 for sediment). The compounds identified as orthophosphate monoesters by (31)P NMR spectroscopy originated mainly from phospholipids (α-glycerophosphate and β-glycerophosphate) and ribonucleic acid (RNA-P), whereas the orthophosphate diesters included mostly DNA (DNA-P). These results suggest that the dynamics of orthophosphate diesters, the production of DNA-P, or the degradation of phospholipids, play an important role in P cycling in Lake Kasumigaura.
authors.affiliation: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. r-shino@nies.go.jp
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Shinohara
authors.forename: Akio
authors.initials: A
authors.lastname: Imai
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kawasaki
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Komatsu
authors.forename: Ayato
authors.initials: A
authors.lastname: Kohzu
authors.forename: Shingo
authors.initials: S
authors.lastname: Miura
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Sano
authors.forename: Takayuki
authors.initials: T
authors.lastname: Satou
authors.forename: Noriko
authors.initials: N
authors.lastname: Tomioka
mesh_terms: D004247:DNA / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry; D005068:Eutrophication; D019015:Geologic Sediments / Q000032:analysis* / Q000737:chemistry; D005994:Glycerophosphates / Q000737:chemistry; D007564:Japan; D060106:Lakes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010710:Phosphates; D010758:Phosphorus / Q000737:chemistry; D017553:Phosphorus Compounds / Q000032:analysis* / Q000737:chemistry*; D010759:Phosphorus Isotopes
chemical_list: D005994:Glycerophosphates; D010710:Phosphates; D017553:Phosphorus Compounds; D010759:Phosphorus Isotopes; D010758:Phosphorus; D004247:DNA; D004492:Edetic Acid; C029620:alpha-glycerophosphoric acid