Blueprint for a lipase support: Use of hydrophobic controlled‐pore glasses as model systems

Abstract

For the commercial exploitation of lipase biocatalysis to be successful, it is essential that effective supports are selected for lipase immobilization. In this study hydrophobic controlled-pore glasses have been used as model systems for the immobilization of Rhizomucor miehei lipase. The effect of pore diameter and surface chemistry on enzyme efficiency in a typical esterification reaction under essentially nonaqueous conditions has been examined. It has been found that pore diameters of at least 35 nm are needed for the lipase to be able to utilize the internal volume of the support particles in the immobilization process. Despite the small size of the substrates in the esterification reaction, even larger pores (>100 nm) are required for the lipase efficiency to become independent of pore diameter; below 100 nm lipase activity and efficiency are markedly reduced. It has also been shown that the chemical nature of the hydrophobic surface plays an important part in catalyst design. Although lipase will adsorb readily to a wide range of hydrophobic groups, the highest catalyst activities are obtained when the glass surface is derivatized to give long alkyl chains; the presence of unsaturated derivatives gonerally leads to a reduction in activity. (c) 1994 John Wiley & Sons, Inc.

Immobilization of a thermophilic solvent-stable lipase from Acinetobacter baylyi and its potential for use in biodiesel production

“…Immobilized ABL on Sepabeads EC-OD and Amberlite XAD16 showed high hydrolytic activity and that on Sepabeads EC-OD provided the highest transesterification activity (Table 1). This result was consistent with those of C. rugosa lipase 20 .When compared with Amberlite XAD16, Sepabeads EC-OD has larger pore diameters, increasing enzyme particle adsorption rate 27 . Smaller particles of EC-OD make the external surface of the matrices accessible to enzyme molecules during assay procedures increasing frequency of collisions between substrates and ABL with catalytic activity.…”

“…In addition, large porous structures facilitate a catalytic expression of immobilized enzyme by reducing limitations on substrate diffusion and product accumulation. Further, improved diffusion enhances biocatalytic reactions by inhibiting substrate or product accumulation inside pores 26,27 . Hence Sepabeads EC-OD were selected as a basal support for the following experiment.…”

Production, purification, characterization, and applications of lipases

“…G. candidum lipases A and B were immobilized on Accurel EP 100 porous polypropylene supports, precoated with ovalbumin to increase stability in organic solvents and at elevated temperatures (Charton and Macrae, 1992). Bosley and Clayton (1994) used hydrophobic controlled pore glasses to immobilize R. miehei lipase. Reetz et al (1995) employed sol-gel entrapment in silica gel to immobilize various lipases.…”

Relationship between water activity and catalytic activity of lipases in organic media

“…But in any case, the loadlnglsupport mass is likely to be less important in influencing enzyme behaviour than loadinglsurface area. Unfortunately, the enzyme-accessible sur- (Bosley and Clayton, 1994). In one case ( 0 ) the support was precoated by treatment with 0.258 g ovalbumin ( g support)-' before immobilisation of the lipase at a loading of 24 kU g-'.…”