Characterization of dipeptidylpeptidase IV (DPP IV) immobilized in Ca alginate beads

Strawberry Protease as a Laundry Detergent Additive Candidate: Immobilization, Compatibility Study with Detergent Ingredients, and Washing Performance Test

The potential of strawberry-derived protease as a component of laundry detergent is investigated. The compatibility of the enzyme with various surfactants, oxidizing agents, and commercial detergents is tested. The immobilized enzyme prepared by immobilizing Co2+ ions together with the enzyme is also tested. Strawberry crude protease shows high stability in the presence of surfactants frequently used in detergents. The enzyme is found to be relatively stable to oxidizing agents. In addition, it is determined that strawberry protease works in excellent compatibility with different commercial solid and liquid detergents in the Turkish market and also maintains its stability very well. Washing tests based on visual examination also reveal that the enzyme improves the washing performance of the tested detergent. All these properties and high activity at alkaline pH make this enzyme a very strong candidate for use in laundry detergent formulations.

Immobilized lignin peroxidase from Ganoderma lucidum IBL-05 with improved dye decolorization and cytotoxicity reduction properties

Use of free microbial enzymes for bioremediation and other industrial applications has several disadvantages like low stability and non-reusability in repeated batch operations. Immobilized enzymes are stable, recoverable and reusable in industrial processes. In this scenario G. lucidum IBL-05 LiP was entrapped in Ca-alginate beads using optimum concentrations of Na-alginate (4%), calcium chloride (0.2M) and glutraldehyde (0.02%). Optimum pH (pH 5) and temperature (55°C) for entrapped LiP were improved as compared to free LiP. Catalytic behavior of LiP also significantly enhanced, as K_m value (0.25mM) decreased and V_max value (868.6μmol/min) increased after ca-alginate entrapment of LiP. Decolorization efficiencies of Sandal reactive dyes after treating with immobilized LiP were in the range of 80-93%. A significant reduction was observed in water quality parameters including, BOD (66.44-98.22%), COD (81.34-98.82%) and TOC (80.21-97.77%) values. The cytotoxicity values for heamolytic and brine shrimp lethality of dye solutions treated with Ca-alginate immobilized LiP reduced up to 2.10-5.06% and 5.43-9.23%, respectively. On the basis of reduced toxicity and cytotoxicity values, it was concluded that Ca-alginate beads entrapped LiP may be an effective biocatalyst for bioremediation of dye based textile industry effluents.

Kinetic Characterization and Effect of Immobilized Thermostable β-Glucosidase in Alginate Gel Beads on Sugarcane Juice

A thermostable β-glucosidase was effectively immobilized on alginate by the method of gel entrapment. After optimization of immobilized conditions, recovered enzyme activity was 60%. Optimum pH, temperature, kinetic parameters, thermal and pH stability, reusability, and storage stability were investigated. The K m and V max for immobilized β-glucosidase were estimated to be 5.0 mM and 0.64 U/ml, respectively. When comparing, free and immobilized enzyme, change was observed in optimum pH and temperature from 5.0 to 6.0 and 60°C to 80°C, respectively. Immobilized enzyme showed an increase in pH stability over the studied pH range (3.0-10.0) and stability at temperature up to 80°C. The storage stability and reusability of the immobilized β-glucosidase were improved significantly, with 12.09% activity retention at 30°C after being stored for 25 d and 17.85% residual activity after being repeatedly used for 4 times. The effect of both free and immobilized β-glucosidase enzyme on physicochemical properties of sugarcane juice was also analyzed.

A novel matrix for the immobilization of acetylcholinesterase

In this study, a new matrix for immobilization of acetylcholinesterase was investigated by using alginate and kappa-carrageenan. The effects of pH, temperature, storage and thermal stability on the free and immobilized acetylcholinesterase activity were examined. Maximum reaction rate (V(max)) and Michaelis-Menten constant (K(m)) was also investigated for free and immobilized enzymes. For free and immobilized enzymes into Ca-alginate and alginate/kappa-carrageenan polymer blends, optimum pH and temperature was found to be 7 and 30 degrees C, respectively. For free enzyme, maximum reaction rate (V(max)) and Michaelis-Menten constant (K(m)) values were found to be 6.35 mM and 50 mM min(-1), respectively, the same values for immobilized enzymes were determined as 8.68, 12.7 mM and 39.7, 52.9 mM min(-1), respectively. Storage and thermal stability of acetylcholinesterase was increased by as a result of immobilization.