Chemical treatments for modification and immobilization to improve the solvent-stability of lipase

Lipase is a lipolytic enzyme that catalyzes the hydrolysis of lipids and esterification reactions. Lipase has been utilized in industrial uses, food processing, and therapeutic applications as a biocatalyst. However, substrates of lipase are often insoluble in water, and this problem limits its utility. Lipases are also used in organic solvents where the solvent-stability of lipase is an important factor. There is a huge number of approaches that can be undertaken to improve the organic solvent-stability of lipases. For example, screening of solvent-tolerant lipase in nature and direct evolution of lipase using genetic engineering are some of the employed approaches. Here, we focus on approaches based on the chemical treatment of lipases for modification and immobilization. The solvent-stability of lipase was improved by the attachment of other molecules, such as surfactants, polymers, and carbohydrates. The immobilization of the enzyme is been known to be an effective approach for not only recycling the enzyme but also its stabilization. Several reports have demonstrated that the solvent-stability of lipase is also improved by immobilization. In this review, we provide an overview of the approaches used to improve the solvent-stability of lipase.