an airlift-type activated sludge reactor using a sponge support medium was fed with wastewater containing 500 mg-n/l of nh4 +-n. in order to establish partial nitrification, the reactor was kept at 35°c. moreover, the reactor was started up with the nahco3 solution as an alkali agent to supply inorganic carbon for enhancement of partial nitrification. the partial nitrification was established d...

Remote loading of insulin and bovine serum albumin (BSA) into neutral or positively-charged liposomes by incubation under a transmembrane pH gradient or non-pH gradient was investigated. Trapping efficiencies in several incubation conditions were compared with those of the conventional reverse-phase evaporation vesicle method (c-REV method). For neutral liposomes, insulin could not be effective...

This paper describes a new method of condensation (focusing) of extended volumes of mixtures of proteins (or other ampholytes) into an isoelectric spectrum of discrete zones located at points of a pH gradient corresponding to the pI value of the individual proteins. In contradistinction to the currently practiced isoelectric focusing in "natural" pH gradients which may require as much as 96 hou...

The influence of a transmembrane pH gradient on the Ca(2+)-induced fusion of phospholipid vesicles, containing free fatty acids, has been investigated. Large unilamellar vesicles composed of an equimolar mixture of cardiolipin, dioleoylphosphatidylcholine, and cholesterol, containing 20 mol % oleic acid, were employed. Fusion was measured using a kinetic assay for lipid mixing, based on fluores...

We studied how soil pH (pHs 4 to 8) influenced the mineralization of low-molecular-weight (LMW)-dissolved organic carbon (DOC) compounds, and how this compared with differences in microbial community structure. The mineralization of LMW-DOC compounds was not systematically connected to differences in soil pH, consistent with soil respiration. In contrast, the microbial community compositions di...

Ion-exchange chromatography (IEC) is a versatile separation technique for profiling the charge heterogeneity of biotherapeutic proteins, including monoclonal antibodies. Despite good resolving power and robustness, ionic-strength-based ion-exchange separations are product specific and time consuming to develop. Although salt gradients are more commonly applied, the utilization of pH gradients c...

We examined the ability of the mucus layer adherent to isolated pieces of rabbit gastric mucosa to maintain a pH gradient across it. Using antimony microelectrodes, a stable pH gradient was detected from pH 2.31 +/- 0.04 on the luminal side to pH 7.26 +/- 0.15 (n = 22) on the epithelial side of the mucus layer. The gradient was maintained for at least 60 minutes. A metabolic inhibitor, potassiu...