Wang Jing-yun*, Ma Cui-li, Bao Yong-ming

(School of life science & biotechnology, Dalian University of Technology, Dalian, 116024)

Abstract: Biomimetic mineralization, which employs biological molecules to induce and drive the formation of inorganic oxides with excellent properties at room temperature, ambient pressure and neutral pH, provides a facile new method for enzyme immobilization. In the present study, for the first time, the biomimetic synthesis of titania was employed for the immobilization of lipase. The optimal encapsulation efficiency (70.1%) and activity recovery (20.3%) of lipase were achieved when 0.5ml protamine solution of 8mg/ml and 0.5ml lipase solution of 6mg/ml were reacted with 1ml Ti-BALDH of 0.25mol/L in phosphate buffer (pH7.5,0.05mmol/L). It was found that the optimum pH of free and encapsulated lipase in titania particles were pH 7.0 and 8.0, respectively,while the optimum temperature were 37 ℃and 45 ℃.Additionally, the lipase encapsulated into titania particles exhibited significantly enhanced pH, thermal, and storage stability, still retained 41% of its initial activity after consecutive 6 cycles.

Key words: Biomimetic mineralization; Titania; Protamine; Encapsulated lipase

E-mail: wangjingyun67@126.com

Journal of Molecular Catalysis, Vol. 25, Issue 4, 2011, 341~347