Lipase immobilization on ceramic supports: An overview on techniques and materials

Enzyme immobilization is a well-known technique that allows the reuse of the biocatalyst and generally improves its stability. These improved characteristics are of fundamental importance to turn industrial biocatalysis into viable and competitive processes. The immobilization of enzymes can occur through several physical or chemical techniques. When the increase or retention of the catalytic activity is the main purpose, physical methods should be used because they cause fewer changes in the enzymatic structure. When the reuse and stability are the main targets, a chemical method should be chosen to guarantee stronger enzyme-support interaction. Several materials can be applied for the immobilization of enzymes, either organic or inorganic. Inorganic materials have some advantages, such as high mechanical, thermal and chemical resistance, which are important for the process economy. Among the inorganic materials, ceramics stand out due to their longer shelf life, pore size control during the manufacturing, and novel applications in several industrial processes. Due to the high versatility of lipases and broad range of relevant applications, they are the focus of this review. Lipases are known to have a high affinity with hydrophobic substrates (such as polymers), so there is a lack of studies regarding general aspects of their immobilization in hydrophilic materials as ceramics. Thus, the objective of this work is to provide an overview of the main techniques of enzyme immobilization in ceramic supports highlighting the immobilization of lipases. A general overview of the key parameters to be considered to obtain immobilized enzymes that can be used on a large scale is also presented.