Immobilization of α-chymotrypsin into the poly(N,N-diallyl-N,N-didodecyl ammonium bromiae)/surfactant nanocapsules

Study of Prepared α-Chymotrypsin as Enzyme Nanoparticles and of Biocatalytic Membrane Reactor

Biocatalytic kinetic effect of α-chymotrypsin enzyme has been investigated in its free and pretreated forms (it was covered by a very thin, porous polymer layer, called enzyme nanoparticle) as well as its immobilized form into pores of polysulfone/polyamide asymmetric, hydrophilic membrane. Trimethoxysilyl and acrylamide-bisacrylamide polymers have been used for synthesis of enzyme nanoparticles. Applying Michaelis-Menten kinetics, the KM and vmax values of enzyme-polyacrylamide nanoparticles are about the same, as that of free enzyme. On the other hand, enzyme nanoparticles retain their activity 20–80 fold longer time period than that of the free enzyme, but their initial activity values are reduced to 13–55% of those of free enzymes, at 37 °C. Enzyme immobilized into asymmetric porous membrane layer remained active about 2.3-fold longer time period than that of native enzyme (at pH = 7.4 and at 23 °C), while its reaction rate was about 8-fold higher than that of free enzyme, measured in mixed tank reactor. The conversion degree of substrate was gradually decreased in presence of increasing convective flux of the inlet fluid phase. Biocatalytic membrane reactor has transformed 2.5 times more amount of substrate than the same amount of enzyme nanoparticles and 19 times more amount of substrate than free enzyme, measured in mixed tank reactor.

Micellar Enzymology- Chemistry and Applications

Enzymes in aqueous environment usually deal with purified enzyme preparations isolated from living matter which does not mimic real catalytic properties in vivo. Interaction of enzymes in nature takes place with different surfaces composed from lipid membranes or they get incorporated into biomembranes. Although Water is not a dominating component in the cytoplasm but plays a structural role by participating in the formation of biocatalytic complexes like glycoproteins. Water is needed to keep biocatalyst in active confirmation and hence plays very crucial role in biocatalytic reactions, activity and stability so that it can be used for various applications. This review focuses on composition, preparation properties and parameters which influence enzymes in reverse micelles and application of micellar enzymology to study protein chemistry, shifting equilibrium of various reactions, to recover various products by partition chromatography and bioremediation of chlorophenolic environmental pollutants.

Surfactants in microbiology and biotechnology: Part 2. Application aspects

Surfactants are amphiphilic compounds which can reduce surface and interfacial tensions by accumulating at the interface of immiscible fluids and increase the solubility, mobility, bioavailability and subsequent biodegradation of hydrophobic or insoluble organic compounds. Chemically synthesized surfactants are commonly used in the petroleum, food and pharmaceutical industries as emulsifiers and wetting agents. Biosurfactants produced by some microorganisms are becoming important biotechnology products for industrial and medical applications due to their specific modes of action, low toxicity, relative ease of preparation and widespread applicability. They can be used as emulsifiers, de-emulsifiers, wetting and foaming agents, functional food ingredients and as detergents in petroleum, petrochemicals, environmental management, agrochemicals, foods and beverages, cosmetics and pharmaceuticals, and in the mining and metallurgical industries. Addition of a surfactant of chemical or biological origin accelerates or sometimes inhibits the bioremediation of pollutants. Surfactants also play an important role in enhanced oil recovery by increasing the apparent solubility of petroleum components and effectively reducing the interfacial tensions of oil and water in situ. However, the effects of surfactants on bioremediation cannot be predicted in the absence of empirical evidence because surfactants sometimes stimulate bioremediation and sometimes inhibit it. For medical applications, biosurfactants are useful as antimicrobial agents and immunomodulatory molecules. Beneficial applications of chemical surfactants and biosurfactants in various industries are discussed in this review.