Synthesis of cinnamyl acetate catalysed by highly reusable cotton-immobilized Pseudomonas fluorescens lipase

Abstract

Cinnamyl acetate as an important fragrance ingredient could be synthesized by lipase-catalysed transesterification in organic systems, but enzyme proteins tended to denature and inactivate for no water lubrication. To improve the non-aqueous stability of lipases, absorbent cotton was taken as an alternative “water” phase to stabilize enzyme proteins. In a mass ratio of 1:1, Pseudomonas fluorescens lipase was immobilized on cotton fibres by physical absorption in a column glass bottle, forming a facile cotton-lipase bioreactor in which the transesterification between cinnamyl alcohol and vinyl acetate processed efficiently. From the molar conversions after reaction for 2 h at 37 °C and 160 rpm, the ability of cotton-lipase to transform substrate was more than 5-folds of native lipase. And even in static state and at 4 °C, the conversion of reaction catalysed by cotton-PFL had 11-fold increase relative to native lipase after 8 h. Recycles showed that the cotton-lipase had an extra-long half-life of activity (t_1/2 = 693 h) and a negligible decay rate in the ability to transform substrate (D_r = 0.08% h⁻¹). All these showed that this lipase had been effectively activated and stabilized by cotton fibres for the numerous hydroxyl groups and fluffy structure.

Keywords:

• Lipase
• absorbent cotton
• immobilization
• transesterification
• catalytic activity
• catalytic stability

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

The authors thank the National Natural Science Foundation of China (31270456 and 30870251), the Open Fund of Tianjin Key Lab of Aquatic Ecology and Aquaculture (TJAE201502) and the National Undergraduate Innovative and Entrepreneurship Training Plan of Tianjin University (201510061015 and 201710061012), for financial support.