Impact of Silver Nanoparticle Contamination on the Genetic Diversity of Natural Bacterial Assemblages in Estuarine Sediments

Recent advancements in the nanotechnology industry have seen a growing interest in integrating silver nanoparticles (Ag-NPs) into consumer and medical products. To date, there has been little research into the toxicological impact that Ag-NPs will have when they enter the marine realm. Of particular concern are the possible effects of Ag-NPs on natural bacterial assemblages, given the antimicrobial activity of silver. In this study, estuarine sediment samples were dosed in triplicate for 20 days from a stock solution of Ag-NPs, with a final cumulative treatment of either 0 μg L−1 (control), 25 μg L−1 or 1000 μg L−1. The experimental tanks were left for a further 10 days to allow for any recovery. Inductively coupled plasma-optical emission spectrometery (ICP-OES) of water and sediment samples confirmed that the Ag-NPs concentration in the aqueous phase decreased after each dosing and were transported to accumulate in the surface layer of the sediment (∼top 3 mm). The overall concentration of Ag-NPs in the water column, however, increased steadily during the 20 days of dosing but decreased rapidly during the following 10 days without dosing. Nevertheless, the Ag-NPs did not have any impact on the prokaryotic abundance in the water column over the incubation period (ANOVA, P Bacteria, was adopted to assess their diversity. Multivariate statistical analyses of presence/absence matrices produced from DGGE profiles revealed negligible differences in bacterial diversity between treatments, suggesting that, under the selected experimental regime, Ag-NPs present little or no impact on estuarine sediment bacterial diversity. Possible reasons for this could include environmental factors, in particular the chloride ions in estuary water affecting the chemistry and behavior of Ag-NPs

Quantitative Protein Composition and Baking Quality of Winter Wheat as Affected by Late Sulfur Fertilization

Increasing prices for wheat products and fertilizers, as well as reduced sulfur (S) contributions from the atmosphere, call for an improvement of product quality and agricultural management. To detect the impact of a time-dependent S fertilization, the quantitative protein composition and the baking quality of two different wheat cultivars, Batis and Türkis, were evaluated. The glutathione concentration in grains serves as a reliable marker of the need for added S fertilizer. The quantitation of gliadins and glutenin subunits by reversed-phase high-performance liquid chromatography confirmed that S-rich proteins significantly increased with S fertilization, whereas the S-poor proteins significantly decreased. Proteome analysis by means of high-resolution protein profiles detected 55 and 37 proteins from Batis and Türkis changed by late S fertilization. A microscale baking test using wholemeal flour was implemented for the evaluation of baking quality, and late S fertilization was found to improve the composition of gluten proteins and baking quality

COGD VI: Synods of the Churches of and after the Reformation: the Dawn of the Reformation (16th-17th Centuries)

This two-volume set includes the critical editions – in some cases the very first critical editions – of a selection of synods of the Churches of and after the Reformation from 1526 to 1616. This collection of synodal decrees represents different confessional families and covers a wide linguistic and geographical spectrum