Mesoporous CLEAs-silica composite microparticles with high activity and enhanced stability

Abstract

A novel enzyme immobilization approach was used to generate mesoporous enzymes-silica composite microparticles by co-entrapping gelatinized starch and cross-linked phenylalanine ammonia lyase (PAL) aggregates (CLEAs) containing gelatinized starch into biomemitic silica and subsequently removing the starch by α-amylase treatment. During the preparation process, the gelatinzed starch served as a pore-forming agent to create pores in CLEAs and biomimetic silica. The resulting mesoporous CLEAs-silica composite microparticles exhibited higher activity and stability than native PAL, conventional CLEAs, and PAL encapsulated in biomimetic silica. Furthermore, the mesoporous CLEAs-silica composite microparticles displayed good reusability due to its suitable size and mechanical properties, and had excellent stability for storage. The superior catalytic performances were attributed to the combinational unique structure from the intra-cross-linking among enzyme aggregates and hard mesoporous silica shell, which not only decreased the enzyme-support negative interaction and mass-transfer limitations, but also improved the mechanical properties and monodispersity. This approach will be highly beneficial for preparing various bioactive mesoporous composites with excellent catalytic performance.

Effects of morphology and pore size of mesoporous silicas on the efficiency of an immobilized enzyme

“…As a result, they have attracted great interest as matrix materials for enzyme immobilization. [11][12][13][14][15][16][17][18][19][20][21][22][23] Various studies have shown that MCM-41 materials have a pore size of just 3.0 nm, and are thus limited to the immobilization of enzymes with small sizes. [15][16][17] Furthermore, despite their high surface areas (ca.…”

Entrapment of cross-linked cellulase colloids in alginate beads for hydrolysis of cellulose

“…Wu and co-workers demonstrated that CLEAs of lipase in alginate beads has higher stability and the leaching of immobilized lipase was prevented [12]. Cui et al reported entrapment of CLEAs of phenylalanine ammonia lyase in mesoporous silica microparticles without leaching over 10 days [22]. Haider and Husain also reported the immobilization of ␤-galactosidase in alginate beads, and the leaching of ␤-galactosidase from the alginate beads was successfully prevented [23].…”

“…In some cases, enzymes in CLEAs even showed higher activities and better stability than free enzymes [18]. Because the size of CLEAs prepared in batch processes often falls in the range of 1-10 m [19], immobilized CLEAs in alignate beads did not experience leaching problems [12,14,[20][21][22][23][24]. For example, Xu and Yang reported the encapsulation of cross-linked tyrosinase aggregates in alginate beads.…”

Bisepoxide-activated Hollow Silica Microspheres for Covalent Immobilization of Lipase from Burkholderia cepacia

“…A very broad variety of materials can be used as supports for enzyme immobilization [27]. These materials may be divided into organic [28], inorganic [29] and hybrid [30] or composite [31].…”