Analysis of microbial exopolysaccharides from industrial water systems

Summary The monosaccharide composition of exopolysaccharides extracted from mixed microbial slimes from cooling towers and process waters of paper machines was determined. Gas chromatographic evidence demonstrated that the microbial slimes found in these industrial systems were heteropolysaccharides, each composed of more than one monosaccharide. Monosaccharides identified in deposit samples were glucose, mannose, galactose, rhamnose, fucose, and glucuronic acid. The methods reported allow efficient extraction and analysis of microbial exopolysaccharides, and the results have implications for slime control strategies in industrial systems.     

Charge injection and charge storage in lipid multilayers

Charge injection and charge storage in lipid multilayers on top of semiconductors have been studied by measuring the small signal capacitance of the structure as a function of applied dc-voltage. It is shown that the injection of holes (and electrons) into the lipid is a thermally activated process, and that no marked difference exists in charge injection properties of simple fatty acids of different carbon chain lengths around room temperature. The charge injection and charge storage properties could be changed by modifications of the lipids. Incorporation of some unsaturated molecules increase the charge injection, and introduction of lipid soluble substances decreases the possibility to store charge etc. The results of some experiments on this line are reported.