The role of microorganisms in the cycling of sedimentary organic carbon is a crucial one. To better understand relationships between molecular composition of a potentially bioavailable fraction of organic matter and microbial populations, bacterial and archaeal communities were characterized using pyrosequencing-based 16S rRNA gene analysis in surface (top 30 cm) and subsurface/deeper sediments...

Phosphate concentrations in rainwater were measured at a Ligurian coastal sampling site (Cap Ferrat, France) from February 1997 to February 1998 to study the impact of wet atmospheric phosphorus (P) input on the surface ocean. Soluble and particulate fractions were differentiated to evaluate the atmospheric supply of bioavailable P. Complexed and reactive phases within the dissolved fraction we...

[1] At least 15% of the 2 Pg y 1 of dissolved organic carbon (DOC) that accumulates in the surface layer of the open ocean has been exported from the ocean margins. The C: N: P stoichiometry of the production and microbial degradation of dissolved organic matter (DOM) in the coastal ocean conditions the quality of the exported substrates. In this work, DOC, dissolved organic nitrogen (DON) and ...

Abstract Purpose The aims of the study were to investigate interaction between fractions organic matter and polycyclic aromatic hydrocarbons (PAHs) in bottom sediments use mussels as passive biomonitors consensus-based sediment quality guidelines for ecological risk assessment sediments. Methods Bottom samples taken from 46 points located Ro?nów reservoir (Poland). (SOM) characteristics include...

Microbial decomposition of organic matter (OM) in river corridors is a major driver nutrient and energy cycles natural ecosystems. Recent advances omics technologies enabled high-throughput generation molecular data that could be used to inform biogeochemical models. With ultrahigh-resolution OM becoming more readily available, particular, the substrate-explicit thermodynamic modeling (SXTM) ha...

We report results from an extensive study on the speciation of zinc (Zn) and its relation to the mobility and bioavailablity of this element in a smelter contaminated soil and an in situ remediated area of this soil 12 yr after the application of cyclonic ash and compost. Emphasis was placed on the role of neoformed precipitates in controlling Zn speciation, mobility and bioavailability under d...

Access to bioavailable nitrogen often limits primary production in marine and freshwater ecosystems. Around 70% of nitrogen transported by rivers worldwide consists of dissolved organic nitrogen (DON), but its bioavailability has been poorly investigated. To assess the potential bacterial growth on DON, we developed a bioassay employing natural DON and bacterial inocula in medium manipulated to...

Sediments are considered as a sink for metals, and the assessment of metal bioavailability for benthic organisms represents a great challenge. Diffusive Gradient in Thin films (DGT), developed to measure labile metals in aquatic media, have more recently been applied to sediment. Nevertheless, few studies have determined the relation between measurements from DGT and bioaccumulation in differen...

A cross-sectional population-based study examined the association between endogenous sex hormones and depressed mood in community-dwelling older men. Participants included 856 men, ages 50-89 yr, who attended a clinic visit between 1984-87. Total and bioavailable testosterone, total and bioavailable estradiol, and dihydrotestosterone levels were measured by radioimmunoassay in an endocrinology ...