Summary Filamentous sulphide‐oxidizing Beggiatoa spp. often occur in large numbers in the coastal seabed without forming visible mats on the sediment surface. We studied the diversity, population structure and the nitrate‐storing capability of such bacteria in the Danish Limfjorden and the German Wadden Sea. Their distribution was compared to the vertical gradients of O2, NO3– and H2S as measured by microsensors. The main Beggiatoa spp. populations occurred in a 0.5–3 cm thick intermediate zone, below the depth of oxygen and nitrate penetration but above the zone of free sulphide. The Beggiatoa spp. filaments were found to store nitrate, presumably in liquid vacuoles up to a concentration of 370 mM NO3–, similar to the related large marine sulphur bacteria, Thioploca and Thiomargarita. The observations indicate that marine Beggiatoa spp. can live anaerobically and conserve energy by coupling sulphide oxidation with the reduction of nitrate to dinitrogen and/or ammonia. Calculations of the diffusive nitrate flux and the potential sulphide oxidation by Beggiatoa spp. show that the bacteria may play a critical role for the sulphur cycling and the nitrogen balance in these coastal environments. 16S rDNA sequence analysis shows a large diversity of these uncultured, nitrate‐storing Beggiatoa spp. Smaller (9–17 µm wide) and larger (33–40 µm wide) Beggiatoa spp. represent novel phylogenetic clusters distinct from previously sequenced, large marine Beggiatoa spp. and Thioploca spp. Fluorescence in situ hybridization (FISH) of the natural Beggiatoa spp. populations showed that filament width is a conservative character of each phylogenetic species but a given filament width may represent multiple phylogenetic species in a mixed population.

Our data suggest that high-dose RSV supplementation positively affects bone, primarily by stimulating formation or mineralization. Future studies of longer duration comprising populations at risk of osteoporosis are needed to confirm these results.

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Microsensors, including a recently developed NO 3؊ biosensor, were applied to measure O 2 and NO 3 ؊ profiles in marine sediments from the upwelling area off central Chile and to investigate the influence of Thioploca spp. on the sedimentary nitrogen metabolism. The studies were performed in undisturbed sediment cores incubated in a small laboratory flume to simulate the environmental conditions of low O 2 , high NO 3 ؊ , and bottom water current. On addition of NO 3 ؊ and NO 2 ؊ , Thioploca spp. exhibited positive chemotaxis and stretched out of the sediment into the flume water. In a core densely populated with Thioploca, the penetration depth of NO 3 ؊ was only 0.5 mm and a sharp maximum of NO 3 ؊ uptake was observed 0.5 mm above the sediment surface. In sediments with only few Thioploca spp., NO 3 ؊ was detectable down to a depth of 2 mm and the maximum consumption rates were observed within the sediment. No chemotaxis toward nitrous oxide (N 2 O) was observed, which is consistent with the observation that Thioploca does not denitrify but reduces intracellular NO 3 ؊ to NH 4 ؉ . Measurements of the intracellular NO 3 ؊ and S 0 pools in Thioploca filaments from various depths in the sediment gave insights into possible differences in the migration behavior between the different species. Living filaments containing significant amounts of intracellular NO 3 ؊ were found to a depth of at least 13 cm, providing final proof for the vertical shuttling of Thioploca spp. and nitrate transport into the sediment.

A biosensor for NO(3)(-) containing immobilized dentrifying bacteria and a reservoir of liquid growth medium for the bacteria was constructed. The bacteria did not have a N(2)O reductase and therefore reduced NO(3)(-) to N(2)O, which was then subsequently quantified by a built-in electrochemical transducer for N(2)O. The only agents interfering with the determination of NO(3)(-) were NO(2)(-) and N(2)O. The sensitivity for NO(2)(-) was identical to the one for NO(3)(-) whereas the sensitivity for N(2)O was 2.4 times higher than for NO(3)(-). Diffusive supply of electron donors to the bacteria from the built-in reservoir of growth medium ensured that the biosensor could work for 2-4 days. The tip diameter was down to 20 μm, and the sensors exhibited perfectly linear responses to nitrate in both freshwater and seawater. The detection limit was ∼1 μM. The 90% response time to changes in NO(3)(-) concentration was from 15 to 60 s at room temperature and about twice that at 6 °C, which was the lowest temperature for successful operation. The new NO(3)(-) biosensor is a very useful tool for the study of nitrogen metabolism in nature.

In this population of middle-aged men suffering from MetS, high dose resveratrol (1,000 mg daily) administration for 4 months significantly lowered serum levels of the androgen precursors androstenedione, DHEA and DHEAS, whereas prostate size and circulating levels of PSA, testosterone, free testosterone, and dihydrotestosterone were unaffected. The present study suggests that resveratrol does not affect prostate volume in healthy middle-aged men as measured by PSA levels and CT acquired prostate volumes. Consequently, we find no support for the use of resveratrol in the treatment of benign prostate hyperplasia.

Throughout the Western world obesity prevalence is steadily increasing, and associated metabolic co-morbidities are projected to rise during the years to come. As weight loss and weight maintenance remains a major problem, new strategies to protect against obesity-related morbidity are needed. There is a clear association between obesity, low-grade inflammation and obesity-associated diseases, thus, the development of new anti-inflammatory substances is urgently needed as these may ultimately pave the way for novel treatments of obesity and lifestyle-related diseases. A candidate molecule is the polyphenolic compound resveratrol, and in the present review, we provide an overview of the field, and discuss the future scientific perspectives. This article is part of a Special Issue entitled: Resveratrol: Challenges in translating pre-clinical findings to improved patient outcomes.

High-resolution NO3 − profiles in freshwater sediment covered with benthic diatoms were obtained with a new microscale NO3 − biosensor characterized by absence of interference from chemical species other than NO2 − and N2O. Analysis of the microprofiles obtained indicated no nitrification during darkness, high rates of nitrification and a tight coupling between nitrification and denitrification during illumination, and substantial rates of NO3 − assimilation during illumination. Nitrification during darkness could be induced by purging the bulk water with O2 gas, indicating that the stimulatory effect on nitrification by illumination was caused by algal production of O2. NH4 + addition did not stimulate nitrification during darkness when O2 was restricted to the upper 1-mm layer, and there was thus a low nitrification potential in the permanently oxic top 1 mm of the sediment.