Supramolecular immobilization of lipase inspired by octopus suckers for biodiesel production

It is still a challenge to design a supramolecular interaction system for immobilizing enzymes efficiently and stably. In this work, inspired by octopus suckers, we used cyclodextrin with a similar structure to the octopus sucker cavity as supramolecular interaction functional units of soft tentacles to immobilize lipase through physical adsorption. By modifying the surface of cyclodextrin with polar hydrophilic groups, the difference in hydrophilic and hydrophobic properties and stability within the molecule were effectively improved, thereby enhancing the cavity suction of cyclodextrin. The enzyme load of the soft tentacles reached 10 mg/g, and the lipase was adsorbed firmly under high strength mechanical action (the retention rate is 66.4%, other physical adsorption under the same conditions is 51.6%). The soft tentacle immobilized lipase showed good dispersibility in the organic phase and its water absorption characteristics could provide oil-water interface for lipase in organic phase reaction, promoting the forward transesterification reaction. Compared with free lipase, the soft tentacle immobilized lipase (L-CDST-Ms) showed the improved activity, which could reach 180% of that of free lipase. The L-CDST-Ms was applied to biodiesel production, and the conversion rate could reach 94%. The results showed that the immobilization method opened up a new way for the application of lipase in transesterification.