41 research outputs found
N-Acetylglucosamine: Production and Applications
N-Acetylglucosamine (GlcNAc) is a monosaccharide that usually polymerizes linearly through (1,4)-β-linkages. GlcNAc is the monomeric unit of the polymer chitin, the second most abundant carbohydrate after cellulose. In addition to serving as a component of this homogeneous polysaccharide, GlcNAc is also a basic component of hyaluronic acid and keratin sulfate on the cell surface. In this review, we discuss the industrial production of GlcNAc, using chitin as a substrate, by chemical, enzymatic and biotransformation methods. Also, newly developed methods to obtain GlcNAc using glucose as a substrate in genetically modified microorganisms are introduced. Moreover, GlcNAc has generated interest not only as an underutilized resource but also as a new functional material with high potential in various fields. Here we also take a closer look at the current applications of GlcNAc, and several new and cutting edge approaches in this fascinating area are thoroughly discussed
Optimization of Chitosan Drying Temperature on The Quality and Quantity of Edible Film
Edible film is a thin layer (biodegradable) used to coat food and can be eaten. In addition edible film serves as a vapor transfer inhibitor, inhibits gas exchange, prevents aroma loss, prevents fat transfer, improves physical characteristics, and as an additive carrier. Edible film made of cassava starch, glycerol and chitosan. Cassava starch is used as raw material because it contains 80% starch. Glycerol serves as a plasticizer and chitosan serves to form films and membranes well. The purpose of this research is to know the characteristic test of edible film by using ANOVA analysis, where the variable of drying of the oven is temperature (70°C, 80°C, 90°C) and time for 3 hours and variables change chitosan (2 gr, 3 gr, 4 gr). The result of this research was obtained the most optimum for water content and water resistance in temperature variable 80 °C and chitosan 4 gr. The best edible films and bubbles on temperature variables are 80 °C and chitosan 4 gr
Recovery of chromium from waste electroplating liquors by ion-exchange on casein. part 1. pilot plant studies
Dosage d'Elements A l'etat de Traces dans les Eaux Souterraines au Moyen de l' Analyse par Activation Neutronique. I. Preconcentration au Moyen de la Resine Echangeuse d'Ions Dowex A1
Production, characterization and purification of chitosanase from Bacillus cereus
A culture medium for a wild strain of Bacillus cereus was developed for chitosanase production by using an experimental design. The factors having the strongest influence on chitosanase production were ammonium sulfate concentration, aeration, pH and the interaction between the first two parameters. Optimal conditions for chitosan hydrolysis were pH 5.8 and 54 oC; however, hydrolysis activity drastically decreased at pH 7.0. The enzyme was purified (single-electrophoretic band) by partitioning in an aqueous two-phase system (ATPS), followed by cation-exchange chromatography with a 66% yield. Chitosanase was mainly collected in the top phase (K = 129) of a 22% PEG 1,500, 13% phosphate (pH = 5.8) and 12% NaCl (w/w) solution, and the main protein contaminants were evenly distributed between the phases (K = 1.07). The apparent molecular weight and the isoelectric point of the chitosanase, determined by SDS-PAGE electrophoresis and by isoelectric focalization, were 47 kDa and 8.8, respectively