Highly Efficient Enzyme Immobilization and Stabilization within Meso-Structured Onion-Like Silica for Biodiesel Production

Abstract

Meso-structured onion-like silica (Meso-Onion-S) was synthesized and used as a host of enzyme immobilization. Meso-Onion-S has a 200–300 nm sized primary meso-structured onion building unit, and each onion unit has highly curved mesopores of 10 nm diameter in a multishell structure. Nanoscale enzyme reactors (NERs) in Meso-Onion-S were prepared via a two-step process of enzyme adsorption and subsequent enzyme cross-linking, which effectively prevents the leaching of cross-linked enzyme aggregates from highly curved mesopores of Meso-Onion-S. As a result, NERs in Meso-Onion-S significantly improved the enzyme stability as well as the enzyme loading. For example, NER of lipase (NER-LP) was stable under rigorous shaking for 40 days, while the control sample of adsorbed LP (ADS-LP) with no enzyme cross-linking showed a rapid inactivation due to rigorous enzyme leaching under shaking. Stable NER-LP was successfully employed to produce biodiesels and fatty acid methyl esters, from the LP-catalyzed transesterification of soybean oil with methanol. Interestingly, the specific activity of NER-LP was 23 and 10 times higher than those of free LP and ADS-LP, respectively, revealing the importance of LP stabilization in the form of NER-LP in the presence of organic solvents.

Dopamine-functionalized mesoporous onion-like silica as a new matrix for immobilization of lipase Candida sp. 99-125

“…1), and this result was in accordance with the previous reports89. The TEM image showed that the DPMS had clear multishell structures with mesopore size of about 13 nm between the layers (Fig.…”

“…These advantages of mesoporous silica supports enable the improvement of activity and stability of enzymes. Recently, a novel meso-structured onion-like silica (Meso-Onion-S), which had highly curved mesopores and highly ordered onion-like multilayer, was synthesized and used as a host for the immobilization of enzyme, and the stability of the enzyme was effectively improved89. However, there are only two reports regarding the study of Meso-Onion-S, and therefore further studies for the immobilization of enzyme in this novel porous material are indeed required.…”

Principles, techniques, and applications of biocatalyst immobilization for industrial application

“…Immobilized lipase in NERs represented more stability during 40 days but free cells showed a rapid inactivation. Specific activity of immobilized lipase was higher than free cells (Jun et al 2012).…”

Sr doping magnetic CaO parcel ferrite improving catalytic activity on the synthesis of biodiesel by transesterification

“…c o m / l o c a t e / f u e l application of homogeneous catalysts (NaOH, KOH) had been restricted by several serious challenges including environmental pollution and separating difficulty [8]. During the past several decades, heterogeneous catalysts, which were consisted of solid acids and solid bases, such as metal oxides, composite metal oxides, zeolites, hydrotalcites, anion exchange resins and lipase immobilized on various supports [9][10][11][12][13][14], were considered as promising catalysts in transesterification reactions. In a word, both solid acids and solid bases were reported to be used for the transesterification [15,16].…”