Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, PO BOX 16300, FI-00076 Aalto, Espoo, Finland.
Department of Chemistry and Materials Science, School of Chemical Engineering, Aalto University, PO BOX 16100, FI-00076 Aalto, Espoo, Finland.
Nat Commun. 2018 Jun 12;9(1):2300. doi: 10.1038/s41467-018-04715-6.
Dehydration reactions proceed readily in water-filled biological cells. Development of biocatalysts that mimic such compartmentalized reactions has been cumbersome due to the lack of low-cost nanomaterials and associated technologies. Here we show that cationic lignin nanospheres function as activating anchors for hydrolases, and enable aqueous ester synthesis by forming spatially confined biocatalysts upon self-assembly and drying-driven aggregation in calcium alginate hydrogel. Spatially confined microbial cutinase and lipase retain 97% and 70% of their respective synthetic activities when the volume ratio of water to hexane increases from 1:1 to 9:1 in the reaction medium. The activity retention of industrially most frequently used acrylic resin-immobilized Candida antarctica lipase B is only 51% under similar test conditions. Overall, our findings enable fabrication of robust renewable biocatalysts for aqueous ester synthesis, and provide insight into the compartmentalization of diverse heterogeneous catalysts.
脱水反应在充满水的生物细胞中很容易进行。由于缺乏低成本的纳米材料和相关技术，模拟这种分隔反应的生物催化剂的发展一直很繁琐。在这里，我们表明阳离子木质素纳米球可以作为水解酶的激活锚，并且通过在海藻酸钠水凝胶中自组装和干燥驱动聚集形成空间受限的生物催化剂，从而能够进行水相酯合成。当反应介质中水量与己烷体积比从 1:1 增加到 9:1 时，空间受限的微生物脂肪酶和脂肪酶保留了各自合成活性的 97%和 70%。在类似的测试条件下，工业上最常用的丙烯树脂固定化南极假丝酵母脂肪酶 B 的活性保留率仅为 51%。总的来说，我们的发现使我们能够制造用于水相酯合成的坚固可再生生物催化剂，并深入了解各种多相催化剂的分隔化。
