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Biological Stimulus-Responsive Hydrogels
Published in Severian Dumitriu, Valentin Popa, Polymeric Biomaterials, 2020
A.K. Bajpai, Sanjana Kankane, Raje Chouhan, Shilpi Goswami
Glucose-sensitive P (MAA-g-EG) gels were synthesized by copolymerizing methacrylic acid and poly(ethylene glycol) monomethacrylate in the presence of activated glucose oxidase (Dai et al., 2008). The surface of the polymer contained a series of molecular “entrances,” which opened and released insulin dependent on glucose concentration. Thus, when these gels are placed in contact with a glucose solution, it results in a pH drop due to oxidation of glucose into gluconic acid. Due to this pH drop, the released protons caused the pendent poly (methacrylic acid) (PMAA) chains of the hydrogel to contract, thus opening the gates to allow insulin transport (see Figure 9.4).
Industrial Biotechnology
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2020
Gluconic acid used in pharmaceutical industries is produced by the fermentation of glucose by strains of A. niger, Penicillium sp., or selected bacteria. In the commercial process, a nutrient solution containing 24%–38% glucose, corn steep liquor, a N2 source and salts, with pH 4.5 is used to culture a selected strain of fungus in shallow pans or in submerged culture conditions to convert glucose into gluconic acid. The pH of the medium is controlled by the addition of a strong solution of sodium hydroxide. Fermentation is carried out at 33°C or 34°C. The medium composition and fermentation conditions determine the production of acids other than gluconic acid (such as citric acid and oxalic acid), and it is therefore important to select a mold strain and fermentation conditions that will avoid the formation of unwanted organic acid. After the fermentation, the cell-free broth is centrifuged and processed to recover gluconic acid.
Enzyme Catalysis
Published in Harvey W. Blanch, Douglas S. Clark, Biochemical Engineering, 1997
Harvey W. Blanch, Douglas S. Clark
Gluconic acid is used primarily in dishwashing detergents, where its ability to chelate metal ions is important in reducing "streaking" of glassware. The production of gluconic acid by Gluconobacter has been examined by Koga et al. 22 and serves to illustrate the coupling of growth and product formation kinetics. Gluconic acid is formed by the microbial oxidation of glucose to glucono- δ-lactone and the subsequent hydrolysis of this intermedate to gluconic acid. glucose→glucono-\delta-lactone→gluconic acid
Removal of orange G dye by Aspergillus niger and its effect on organic acid production
Published in Preparative Biochemistry & Biotechnology, 2023
Juana Lira Pérez, Refugio Rodríguez Vázquez
A. niger in the presence of OG dye used most of the glucose in the Wunder medium[22](6.87 g/L out of 10 g/L) as substrate to produce gluconic acid, a transformation catalyzed by the enzyme glucose oxidase (EC 1.1.3.4). The formation of gluconic acid by A. niger occurs extracellularly because the enzyme glucose oxidase can be found in the cell wall or secreted into the culture medium.[45–47] It has been reported that A. niger strains under suitable conditions of high substrate glucose concentrations (100–200 g/L), low nitrogen and phosphorus concentrations (20 mM) and high aeration rate, can achieve theoretical conversion efficiencies on glucose to gluconic acid, via the enzyme glucose oxidase, of up to 95%.[48,49]
Extremozymes used in textile industry
Published in The Journal of The Textile Institute, 2022
Priyanka Kakkar, Neeraj Wadhwa
Bleaching is important wet processing to remove any natural pigment and provide pure white cotton fibers. Glucose oxidase enzyme is used for the bleaching of cotton fibers and the process is called biobleaching. In the presence of oxygen, glucose oxidase enzyme oxidise the glucose molecule into gluconic acid and hydrogen peroxide. Catalase, laccase is used to remove the left behind hydrogen peroxide called bleach cleanup. Small amount of catalase is sufficient to convert it into hydrogen and oxygen as shown in Figure 2. Catalase only acts on the hydrogen peroxide present on the fabric and the other material remain unharmed. Enzymatic cleaning of peroxide is eco-friendly and use less water by avoiding extensive washing and less energy consumption (Shahid et al., 2016), (Roy Choudhury, 2020). Geobacillus thermo pakistaniensis is used to isolate catalase and laccase (Basheer et al., 2017; Shaeer et al., 2019). Recombinant enzyme of catalase has been produced by encoding the gene CAT responsible for cold adaptive catalytic activity in psychrophile and its hetrogenous expression in E.coli. It is active in wide range of temperature form 20 to 70 °C (Sarmiento et al., 2015). Biopolishing is the process to remove fuzz and pilling from the fabric surface. Cellulase enzyme is used to treat the fabric surface. It makes the fabric texture smoother, better appearance, color brightness, and improves water absorbing property. Controlled enzymatic treatments optimise the surface properties of the fabric but may result in decrease in tensile strength which is commercially acceptable (Roy Choudhury, 2020).
Impacts of desugarization and drying methods on physicochemical and functional properties of duck albumen powder
Published in Drying Technology, 2019
Tran Hong Quan, Soottawat Benjakul
Nowadays, egg albumen, especially in the powder form, is an important raw material for food industry. This is owing to low space required for transportation and storage, low susceptibility to microbial growth, and uniformity.[7] In general, the original liquid form of albumen contains glucose about 4 g/L. Glucose is involved in Maillard reaction of albumen during drying process. This contributes to undesirable brown color. Furthermore, the glucose–cephalin reaction (a reaction between a cephalin amino group and aldehydes of glucose) is responsible for off-flavor development during dehydration and storage.[3,8] To conquer this drawback, desugarization is a crucial step before dehydration to obtain perfectly white powders. Desugarization can be conducted using bacterial or yeast fermentations. However, these processes pose some bacteriological problems. The use of commercial glucose oxidase and catalase is effectively converts glucose into gluconic acid.[8] Enzymatic treatment for glucose removal before dehydration was the best method to prepare Egyptian egg albumen powder.[9] Enzymatic glucose hydrolysis has been implemented in industrial scale prior to spray drying of hen egg albumen.[10] Dried egg albumen can be manufactured by spray drying or freeze drying. Freeze drying is one of the best drying technologies for maintaining the quality of foods. This technology is suitable for heat-sensitive food components. However, freeze drying takes a long period of time for operation and it has high capital and process costs.[11–13] Spray-drying is the most popular drying technology used for production of hen egg albumen powder.[3] Ma et al.[14] reported optimum spray-drying conditions including spraying flow of 22 mL/min, feeding temperature of 39.8 °C, and inlet-air temperature of 178.2 °C, in which high quality and functional properties of hen egg albumen were obtained. Moderate spray-drying conditions yielded dried hen albumen and whole egg, which could be applied in baking, dressings, and confectionery products.[15]