The Preparation And Applications Of Lipase Immobilized On Porous Ceramic Monoliths

The pores inside microbeads and porous ceramic monoliths are highly interconnected with hierarchical pore diameters between 10-200 nm and 30-100 μm. Porous ceramic monoliths(PCM), with wide channels and a good permeability, can minimize the diffusion resistance. In this study, lipase from Candida sp. 99-125 was immobilized on amino-functionalized, epoxy-functionalized or dopamine functionalized porous ceramic monoliths. The activity and stability of the immobilized lipases were investigated. The immobilized lipases were used as catalysts for the production of biodiesel and oil gelling agent under environmentally benign conditions. The details in this study were summarized as follows:Lipase Candida sp. 99-125 was immobilized on the amino- or epoxy-functionalized PCM and the immobilizing conditions were optimized. For the lipase immobilized on amino-functionalized PCM(Lipase@Amino-PCM), the initial lipase concentration and immobilizing time were 45 mg/m L and 2 h, respectively. The obtained lipase loading amount was 5.7 mg/g and the specific activity was 12.3 U/g. For the lipase immobilized on epoxy-functionalized PCM(Lipase@Epoxy-PCM), the initial lipase concentration and immobilizing time were 30 mg/m L and 3 h, respectively. The obtained lipase loading amount was 6.4 mg/g and the specific activity was 15.7U/g. The properties of the obtained biocatalysts were also investigated. The results indicated that the stabilities of immobilized lipases were improved significantly compared to native lipase. Then, the biocatalysts were used to catalyze the production of biodiesel.Lipase Candida sp. 99-125 was immobilized on the dopamine functionalized PCM and the immobilizing conditions were optimized. The initial lipase concentration and immobilizing time were 30 mg/m L and 5 h, respectively. The obtained lipase loading amount was 12.6 mg/g and the specific activity was 16.6 U/g. The properties of the obtained biocatalysts were also investigated. The results indicated that the stabilities of immobilized lipases were improved significantly compared to native lipase. Then, the biocatalysts were used to catalyze the production of biodiesel.Five kinds of sugar-derived oil gelling agents with different alkyl chain length were prepared and named Man-6, Man-8, Man-10, Man-12 and Man-14, respectively. The obtained yield of Man-6, Man-8, Man-10, Man-12 and Man-14 were 81%,82%,70%,59% and 61%, respectively. All the oil gelling agents have the gelling ability to get co-congealed along with the oil and gel the oil phase. Take Man-8 as an example, the yield of this oil gelling agent was more than 78% after 48 h reaction that catalyzed by the immobilized lipases. After the 5th batch reaction, more than 50% of yield can be maintained. Furthermore, the results of gelation tests indicated that the oil gelling agent can be effectively used in can gel various hydrocarbons and oils. When the oil gelling agent was used to recover diesel from a biphasic mixture, more than 90% of the initial diesel can be recovered.