Explore the vast range of titles available.

Members of the phylum Bacteroidetes are abundant in many marine ecosystems and are known to have a pivotal role in the mineralization of complex organic substrates such as polysaccharides and proteins. We studied the decomposition of the algal glycans laminarin and alginate by ‘ Gramella forsetii ’ KT0803, a bacteroidetal isolate from North Sea surface waters. A combined application of isotope labeling, subcellular protein fractionation and quantitative proteomics revealed two large polysaccharide utilization loci (PULs) that were specifically induced, one by alginate and the other by laminarin. These regulons comprised genes of surface-exposed proteins such as oligomer transporters, substrate-binding proteins, carbohydrate-active enzymes and hypothetical proteins. Besides, several glycan-specific TonB-dependent receptors and SusD-like substrate-binding proteins were expressed also in the absence of polysaccharide substrates, suggesting an anticipatory sensing function. Genes for the utilization of the beta-1,3-glucan laminarin were found to be co-regulated with genes for glucose and alpha-1,4-glucan utilization, which was not the case for the non-glucan alginate. Strong syntenies of the PULs of ‘ G. forsetii ’ with similar loci in other Bacteroidetes indicate that the specific response mechanisms of ‘ G. forsetii ’ to changes in polysaccharide availability likely apply to other Bacteroidetes . Our results can thus contribute to an improved understanding of the ecological niches of marine Bacteroidetes and their roles in the polysaccharide decomposition part of carbon cycling in marine ecosystems.

The shallow water bivalve Codakia orbicularis lives in symbiotic association with a sulfur-oxidizing bacterium in its gills. The endosymbiont fixes CO 2 and thus generates organic carbon compounds, which support the host's growth. To investigate the uncultured symbiont's metabolism and symbiont–host interactions in detail we conducted a proteogenomic analysis of purified bacteria. Unexpectedly, our results reveal a hitherto completely unrecognized feature of the C. orbicularis symbiont's physiology: the symbiont's genome encodes all proteins necessary for biological nitrogen fixation (diazotrophy). Expression of the respective genes under standard ambient conditions was confirmed by proteomics. Nitrogenase activity in the symbiont was also verified by enzyme activity assays. Phylogenetic analysis of the bacterial nitrogenase reductase NifH revealed the symbiont's close relationship to free-living nitrogen-fixing Proteobacteria from the seagrass sediment. The C. orbicularis symbiont, here tentatively named ‘ Candidatus Thiodiazotropha endolucinida’, may thus not only sustain the bivalve's carbon demands. C. orbicularis may also benefit from a steady supply of fixed nitrogen from its symbiont—a scenario that is unprecedented in comparable chemoautotrophic symbioses. The S-oxidizing symbiont of the bivalve Codakia orbicularis encodes all proteins required for biological nitrogen fixation. The symbiont's NifH is phylogenetically close to free-living N-fixing Proteobacteria associated with seagrass sediment.

BackgroundAssistive technologies have the potential to facilitate everyday life of people with dementia and their families. Close collaboration with affected people and interdisciplinary research are essential to understand and address the needs of prospective users. In this study, we present the results of the evaluation of such an assistive system prototype.AimsChallenges from the patient and caregiver side, technical and design problems and acceptance and usability with regard to our special target group were evaluated.MethodsMEMENTO, a system of two e-ink tablets and a smartwatch, was tested in the domestic environment of dementia patients. Thirty participants from Italy, Spain and Austria took part in a 3-month field trial and compared the MEMENTO system to traditional strategies in everyday life. Quantitative and qualitative data were collected and frequency of use of the system was monitored.ResultsThere were no significant changes in quantitative measurements, such as activities of daily living and caregiver burden over the duration of the 3-month field trial. More frequent usage was significantly correlated with positive attitude towards technology (r = 0.723, p < 0.05), but not with age. The design of the system was positively emphasized, reducing fear of the technology on the one hand and stigmatization on the other.ConclusionWe show that a positive attitude towards technology is the essential variable for successful implementation of such systems, regardless of age. Participants showed great interest in digital solutions and agreed that technological systems will help in maintaining independency of persons with cognitive dysfunction in the future.