Meso-structured onion-like silica (Meso-Onion-S) wassynthesizedand used as a host of enzyme immobilization. Meso-Onion-S has a 200â300nm sized primary meso-structured onion building unit, and each onionunit has highly curved mesopores of 10 nm diameter in a multishellstructure. Nanoscale enzyme reactors (NERs) in Meso-Onion-S were preparedvia a two-step process of enzyme adsorption and subsequent enzymecross-linking, which effectively prevents the leaching of cross-linkedenzyme aggregates from highly curved mesopores of Meso-Onion-S. Asa result, NERs in Meso-Onion-S significantly improved the enzyme stabilityas well as the enzyme loading. For example, NER of lipase (NER-LP)was stable under rigorous shaking for 40 days, while the control sampleof adsorbed LP (ADS-LP) with no enzyme cross-linking showed a rapidinactivation due to rigorous enzyme leaching under shaking. StableNER-LP was successfully employed to produce biodiesels and fatty acidmethyl esters, from the LP-catalyzed transesterification of soybeanoil with methanol. Interestingly, the specific activity of NER-LPwas 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-LPin the presence of organic solvents. [ABSTRACT FROM AUTHOR]