Synthesis of cinnamyl acetate catalysed by highly reusable cotton-immobilized Pseudomonas fluorescens lipase |
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Authors: | Xiao Wang Xiaohong Wang Yanling Xu Jie Kang Ying Zhang |
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Institution: | Tianjin Key Laboratory of Aqua-ecology and Aquaculture, College of Basic Science, Tianjin Agriculture University, Tianjin, P.R. China |
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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 (t1/2?=?693?h) and a negligible decay rate in the ability to transform substrate (Dr?=?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. |
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Keywords: | Lipase absorbent cotton immobilization transesterification catalytic activity catalytic stability |
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