PENGARUH SUHU INKUBASI TERHADAP AKTIVITAS LIPASE DAUN PEPAYA (Carica papaya L) YANG DIAMOBILISASI DALAM PASIR LAUT

The silica content in sea sand can be used to immobilize lipase from papaya leaf. Research on the influence of incubation temperature on sea sand immobilized lipase from papaya leaf (Carica papaya L) has been carried out. The aim of research is determining the influence of incubation temperature on sea sand immobilized lipase from papaya leaf (Carica papaya L). The method used in this study was a completely randomized design with temperature at 30, 40, 50, 60, 70°C. The results show that lipase from papaya leaf (Carica papaya L) had successfully immobilized in the sea sand and the optimum temperature stability of lipase immobilized in sea sand at 50°C with an activity is 53.000 µmol/g.jam Keywords : immobilized, lipase, papaya leaf, sea sand.

Jet cutter as tool to immobilize lipase for biodiesel production

The use of lipases as a biocatalyst for industrial applications is an interesting route due to technical aspects but also to reduce environmental impacts caused by the use of chemical catalysts. Gel immobilization of the enzyme allows its reuse and avoids contamination of the product with residual portions of free enzyme. However, a typical technique available for enzyme immobilization is based on dripping driven by gravity which produces big particles and low rate of production. The reduction of size can improve the mass transfer by increasing the contact area. Thus, aiming to increase the rate of particles production and reduce the size of particles, the objective of this work was to encapsulate lipase, using a tool designed to cut the jet produced by pumping, called as Jet Cutter.

Development of Emulsion Gels and Macroporous Hydrogels and their Applications to Metal Adsorption and Enzyme Reaction

Emulsion gels, that is, hydrogels containing randomly distributed oil microdroplets, and macroporous hydrogels with randomly distributed, non-interconnected, sphere-like macropores with several micrometers in diameter were prepared by the emulsion-gelation method [1]. This method involves the synthesis of hydrogels in an oil-in-water (O/W) emulsion by free radical copolymerization of a monomer with a cross-linker, followed by the washing (removal) of the dispersed oil as a pore template (porogen). The observations of oil droplets in an emulsion and internal structure of a macroporous hydrogel demonstrate that the oil droplets act as a pore-template. The pore size and porosity can be adjusted by varying the O/W volume ratios and surfactant amounts [2]. These gels are used as a bulk and have excellent diffusional permeability to a solute and solvent. The emulsion-gelation method can yield potentially intelligent gels in which the macropores function as spaces for reaction, separation and storage. Novel emulsion gel adsorbents, that is, polymeric hydrogels containing randomly distributed microdroplets of an organic extractant (an oil-soluble complexing agent), were developed for metal adsorption [3,4]. The emulsion gel containing an organophosphorus extractant and organosulfur extractant successfully adsorbed In (III) and Pd (II) ions, respectively. Novel macroporous polymeric hydrogels were developed to entrap and immobilize lipase as a model enzyme [5]. The lipase immobilized within the macroporous hydrogel successfully catalyzed the hydrolysis of triacetin in a model enzyme reaction without leakage of lipase or loss of activity during repeated use.

Superparamagnetic Fe3O4nanoparticles modified by water-soluble and biocompatible polyethylenimine for lipase immobilization with physical and chemical mechanisms

A solvothermal method was applied to prepare magnetic nanoparticles. And after being coated by PEI, the nanoparticles were able to be modified by glutaraldehyde. Then the supports can be used to immobilize lipase covalently, as well asviaionic exchange.