Maltooligosaccharides (MOS) are homooligosaccharides that consist of 3-10 glucose molecules linked by α-1,4 glycosidic bonds. As they have physiological functions, they are commonly used as ingredients in nutritional products and functional foods. Many researchers have investigated the potential applications of MOS and their derivatives in the pharmaceutical industry.
View Article and Find Full Text PDFThe aim of this study was to develop immobilized enzyme systems that reduce carbonyl compounds to their corresponding alcohols. The demand for natural aromas and food additives has been constantly growing in recent years. However, it can no longer be met by extraction and isolation from natural materials.
View Article and Find Full Text PDFA microbial biosensor for 2-phenylethanol (2-PE) based on the bacteria Gluconobacter oxydans was developed and applied in monitoring of a biotechnological process. The cells of G. oxydans were immobilized within a disposable polyelectrolyte complex gel membrane consisting of sodium alginate, cellulose sulphate and poly(methylene-co-guanidine) attached onto a miniaturized Clark oxygen electrode, forming whole cell amperometric biosensor.
View Article and Find Full Text PDFDirect comparison of key physical and chemical-engineering properties of two representative matrices for multipurpose immobilisations was performed for the first time. Polyvinyl alcohol lens-shaped particles LentiKats® and polyelectrolyte complex microcapsules were characterised by advanced techniques with respect to the size distribution of the particles, their inner morphology as revealed by fluorescent probe staining, mechanical resistance, size-exclusion properties, determination of effective diffusion coefficient and environmental scanning electron microscope imaging. While spherical polyelectrolyte complex microcapsules composed of a rigid semipermeable membrane and a liquid core are almost uniform in shape and size (diameter of 0.
View Article and Find Full Text PDFRecombinant Escherichia coli cells, over-expressing cyclopentanone monooxygenase activity, were immobilized in polyelectrolyte complex capsules, made of sodium alginate, cellulose sulfate, poly(methylene-co-guanidine), CaCl(2) and NaCl. More than 90% of the cell viability was preserved during the encapsulation process. Moreover, the initial enzyme activity was fully maintained within encapsulated cells while it halved in free cells.
View Article and Find Full Text PDFNovel and selective microbial amperometric biosensors that use Gluconobacter oxydans cells to monitor the bacterial bioconversion of glycerol (Gly) to 1,3-propanediol (1,3-PD) are described. Two different mediators, ferricyanide and flexible polyvinylimidazole osmium functionalized polymer (Os-polymer), were employed to prepare two different microbial biosensors, both of which gave high detection performance. The good operational stabilities of both types of biosensor were underlined by the ability to detect 1,3-PD throughout 140 h of continuous operation.
View Article and Find Full Text PDFBacteria belonging to the genus Acetobacter and Gluconobacter, and enzymes isolated from them, have been extensively used for biosensor construction in the last decade. Bacteria used as a biocatalyst are easy to prepare and use in amperometric biosensors. They contain multiple enzyme activities otherwise not available commercially.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
October 2006
Glycerokinase from Cellulomonas sp. was used to develop biosensor based on flow calorimetry for quantitative analysis of glycerol during bioconversion process. An automatic flow injection analysis device with the glycerol biosensor was built and tested during growth on glycerol of 1,3-propanediol-producing bacteria.
View Article and Find Full Text PDFStructural properties of cellulose gels Perloza MT, materials designed for the preparation of chromatographic adsorbents and immobilized biocatalysts, having a different content of polymer were investigated using a batch solute exclusion method. A homologous set of dextrans with a wide range of molecular weights was used to probe the pore accessibility of the gel particles. It was found that all gels possessed a bimodal pore structure where macropores were fully accessible to all dextrans whereas the solute partitioning depending on the molecule size occurred in the micropores of the swollen polymer network.
View Article and Find Full Text PDFThermal inactivation of jack bean urease (EC 3.5.1.
View Article and Find Full Text PDF