Impact of Physicochemical Character of Hydrophobic Porous Carrier on Reactivity of Immobilized Lipase Progressing Toward Higher Reaction Rate and High Yield in Repeated Use

Wheat germ lipase: isolation, purification and applications

In recent years, wheat germ lipase (WGL) is attracting considerable interest. To date, several WGL applications have already been described: (i) fats and oils modification; (ii) esterification reactions in organic media, accepting a wide range of acids and alcohols as substrates; (iii) the asymmetric resolution of various chiral racemic intermediates; (iv) more recently, the promiscuous activity of WGL has been shown in carbon-carbon bond formation. To date, no crystallographic structure of this enzyme has been published, which means its activity, catalytic potential and substrate scope is being assessed empirically. Therefore, new catalytic activities of this enzyme are constantly being discovered. Taking into account the emergency and the current interest in environmentally sustainable processes, this review aims to highlight the origin, isolation, stabilization by immobilization and applications of the wheat germ lipase.HIGHLIGHTSWheat germ as an inexpensive source of biocatalystsWheat germ lipase an efficient catalyst for various chemical transformationsWheat germ lipase in food productionIndustrial applications of wheat germ lipaseWheat germ lipase as a promiscuous biocatalystImmobilization of wheat germ lipase as a method of stabilization.

Extraction and reimmobilization of used commercial lipase from industrial waste

In industrial application, immobilized lipase are typically not reused and served as industrial waste after a certain process is completed. The capacity on the reusability of the spent lipase is not well studied. This current study embarks on reusing the remaining lipase from the spent immobilized enzyme. Active lipases were recovered using a simple reverse micellar extraction (RME). RME is the extraction process of targeted biomolecules using an organic solvent and a surfactant. This method was the first attempt reported on the recovery of the lipase from the used immobilized lipase. RME of the spent lipase was done using the nonionic Triton X-100 surfactant and toluene. Various parameters were optimized to maximize the lipase recovery from the used immobilized lipase. The optimum forward extraction condition was 0.075 M KCl, and backward conditions were at 0.15 M Triton X-100/toluene (pH 6, 2 M KCl) with recovery of 66%. The extracted lipase was immobilized via simple adsorption into the ethanol pretreated carrier. The optimum conditions of immobilization resulted in 96% of the extracted lipase was reimmobilized. The reimmobilized lipase was incubated for 20 h in pH 6 buffer at 50 °C of water bath shaker. The reimmobilized lipase still had 27% residual activity after 18 h of incubation, which higher thermal stability compared to the free lipase. In conclusion, the free lipase was successfully extracted from the spent immobilized lipase and reimmobilized into the new support. It exhibited high thermal stability, and the reusability of the spent lipase will promote continued use of industrial lipase and reduce the cost of the manufacturing process.

The Immobilization of Lipases on Porous Support by Adsorption and Hydrophobic Interaction Method

Four major enzymes commonly used in the market are lipases, proteases, amylases, and cellulases. For instance, in both academic and industrial levels, microbial lipases have been well studied for industrial and biotechnological applications compared to others. Immobilization is done to minimize the cost. The improvement of enzyme properties enables the reusability of enzymes and facilitates enzymes used in a continuous process. Immobilized enzymes are enzymes physically confined in a particularly defined region with retention to their catalytic activities. Immobilized enzymes can be used repeatedly compared to free enzymes, which are unable to catalyze reactions continuously in the system. Immobilization also provides a higher pH value and thermal stability for enzymes toward synthesis. The main parameter influencing the immobilization is the support used to immobilize the enzyme. The support should have a large surface area, high rigidity, suitable shape and particle size, reusability, and resistance to microbial attachment, which will enhance the stability of the enzyme. The diffusion of the substrate in the carrier is more favorable on hydrophobic supports instead of hydrophilic supports. The methods used for enzyme immobilization also play a crucial role in immobilization performance. The combination of immobilization methods will increase the binding force between enzymes and the support, thus reducing the leakage of the enzymes from the support. The adsorption of lipase on a hydrophobic support causes the interfacial activation of lipase during immobilization. The adsorption method also causes less or no change in enzyme conformation, especially on the active site of the enzyme. Thus, this method is the most used in the immobilization process for industrial applications.