Immobilization of lipase from Mucor miehei and Rhizopus oryzae into mesoporous silica—The effect of varied particle size and morphology

Abstract

Immobilization of enzymes usually improves the recyclability and stability and can sometimes also improve the activity compared to enzymes free in solution. Mesoporous silica is a widely studied material as host for immobilized enzymes because of its large internal surface area and tunable pores. It has previously been shown that the pore size is critical both for the loading capacity and for the enzymatic activity; however, less focus has been given to 20 the influence of the particle size. In this work the effect of particle size and particle morphology on the immobilization of lipase from Mucor miehei and Rhizopus oryzae have been investigated. Three kinds of mesoporous silica, all with 9 nm pores but with varying particle size (1000 nm, 300 nm and 40 nm) have been synthesized and were used as host for the lipases. The two lipases, which have the same molecular size but widely different 25 isoelectric points, were immobilized into the silica particles at varied pH values within the interval 5 to 8. The 300 nm particles were proven to be the most suitable carrier with respect to specific activity for both enzymes. The lipase from Mucor miehei was more than four times as active when immobilized at pH 8 compared to free in solution whereas the difference was less pronounced for the Rhizopus oryzae lipase. 30

Comparison of mesoporous silicate supports for the immobilisation and activity of cytochrome c and lipase

“…Differences in morphology may also contribute to the lower loadings of enzyme, (Fig 2) with more facile access of the enzyme molecules into the cylindrical pores of SBA-15 in comparison to the slit shaped pores of PPS. Such differences have been previously reported to influence the degree of enzyme loading [40,41]. It should be noted that the amounts of cytochrome c and of lipase adsorbed on PPS was lower than on SBA-15.…”

Enzyme immobilization by adsorption: a review

“…These give rise to the interactions sufficiently strong for the enzyme-carrier binding (adsorption) to occur (Kosaka et al 2007;Gustafsson et al 2012;Wu et al 2012). When such groups are absent, the carrier is subjected to a chemical modification (Cho et al 2012;Mendes et al 2012;Zaidan et al 2012).…”

“…Lipases were also immobilized on other materials such as buthyl and octadecyl sepabeads (Branco et al 2010), cotton flannel cloth (Karimpil et al 2012), olive pomace powder (Yucel 2012) and commercial ion exchange resin Lewatit. By contrast, among inorganic carriers widely used there are different silicas, such as mesoporous silicas (Gustafsson et al 2012), e.g. SBA-15 or MSU-H (Yu and Fang 2013), vesicular silica (Wu et al 2012), fumed silica (Kramer et al 2010), silanized silica (Zheng et al 2012), silica sol-gel film (Lee et al 2010) and commercial silica-based products Celite (Brem et al 2011) and Celite 545 (Kumar and Kanwar 2011;see Fig.…”

Mesoporous Building Blocks: Synthesis and Characterization of Mesoporous Silica Particles and Films

“…As reported in other studies, these are most useful for other applications such as drug delivery or enzyme immobilization [67,228].…”

“…The separated particles presented in Paper IV and Paper V are already in use for drug delivery studies [67], and for enzyme immobilization [228], and this work should be ongoing. Furthermore, the catalytic performance of fibers and rods are tested, and doping experiments of the rods in combination with nanoparticle growth in the pores are currently performed for their use in methanol conversion.…”