Interaction of liposomes with bile salts investigated by asymmetric flow field-flow fractionation (AF4): A novel approach for stability assessment of oral drug carriers.

For oral drug delivery the stability of liposomes against intestinal bile salts is of key importance. Here, asymmetric flow field-flow fractionation (AF4) coupled to multi-angle laser light scattering (MALLS) and a differential refractive index (dRI) detector was employed to monitor structural re-arrangement of liposomes upon exposure to the model bile salt taurocholate. For comparison, a conventional stability assay was employed using a hydrophilic marker and size exclusion chromatography (SEC) to separate released from liposome-entrapped dye.

Freshwater copepod carcasses as pelagic microsites of dissimilatory nitrate reduction to ammonium.

A considerable fraction of freshwater zooplankton was recently found to consist of dead specimens that sink to the lake bottom. Such carcasses host intense microbial activities that may promote oxygen depletion at the microscale. Therefore, we tested the hypothesis that sinking zooplankton carcasses are microsites of anaerobic nitrogen cycling that contribute to pelagic fixed-nitrogen loss even in the presence of ambient oxygen.

Responses of an Agricultural Soil Microbiome to Flooding with Seawater after Managed Coastal Realignment.

Coastal areas have become more prone to flooding with seawater due to climate-change-induced sea-level rise and intensified storm surges. One way to cope with this issue is by "managed coastal realignment", where low-lying coastal areas are no longer protected and instead flooded with seawater. How flooding with seawater impacts soil microbiomes and the biogeochemical cycling of elements is poorly understood.

Novel anammox bacteria and nitrogen loss from Lake Superior.

Anaerobic ammonium oxidizing (anammox) bacteria own a central position in the global N-cycle, as they have the ability to oxidize NH to N under anoxic conditions using NO. They are responsible for up to 50% of all N released from marine ecosystems into the atmosphere and are thus indispensible for balancing the activity of N-fixing bacteria and completing the marine N-cycle. The contribution, diversity, and impact of anammox bacteria in freshwater ecosystems, however, is largely unknown, confounding assessments of their role in the global N-cycle.

Archaeal lipids in oral delivery of therapeutic peptides.

Archaea contain membrane lipids that differ from those found in the other domains of life (Eukarya and Bacteria). These lipids consist of isoprenoid chains attached via ether bonds to the glycerol carbons at the sn-2,3 positions. Two types of ether lipids are known, polar diether lipids and bipolar tetraether lipids.