Rice straw enhancing catalysis of Pseudomonas fluorescens lipase for synthesis of citronellyl acetate

Abstract

Citronellyl acetate as an important flavor, can be effectively synthesized by lipase catalysis in nonaqueous system. But lipases usually behave low catalytic activity due to aggregation and denaturation of them in organic phase. To enhance the nonaqueous catalysis, based on the mechanism of lipases activated at water/oil (organic phase) interface, the inexpensive race straw was processed into powder and filaments on which Pseudomonas fluorescens lipase was immobilized by physical adsorption, used for synthesis of citronellyl acetate via transesterification of citronellol and vinyl acetate. Results showed that the desired loading was 10 mg lipase immobilized on 30 mg rice straw filaments or 25 mg rice straw powder. When the two immobilized lipases were employed in the reaction system consisted of 1-mL citronellol and 2-mL vinyl acetate at 37 ℃ and 160 rpm, the conversions all reached 99.8% after 12 h. Under the reaction condition, the conversion catalyzed by 10 mg native lipase was 85.1%. Undergoing six times of 8-h reuses in the organic system, the filament and power immobilized lipases had weak activity attenuation rates 0.36 and 0.32% h −1 , lower than 1.52% h −1 of native lipase. Even at the room temperature and the static state without shaking and stirring, the rice straw filaments immobilized lipase could brought conversion 62.9% after 10 h but the native lipase only gave 37.0%. Obviously, the rice straw, especially its filaments, is an inexpensive and available natural material to prepare immobilized lipase with desired catalysis in organic phase, meant significant potential in flavor industry.

Immobilization of Pseudomonas fluorescens Lipase on Hollow Poly(o-phenylenediamine) Microspheres and Its Application in the Preparation of Citronellyl Acetate

“…Therefore, the effect of acetaldehyde on immobilized PFL can be ignored during reuse. Rice straw was processed into powder and filaments, on which PFL was immobilized (RSD-PFL and RSF-PFL) for a transesterification reaction to produce citronellyl acetate in a solvent-free system [28]. The highest yield reached 96%.…”

“…Lipase-catalyzed transesterification for citronellyl acetate is a typical green and environmentally friendly process, with the advantages of mild reaction conditions, high catalytic efficiency, and strong catalytic specificity. For its production, inexpensive raceme straw was processed into powder and filaments, on which Pseudomonas fluorescens lipase was immobilized by physical adsorption to synthesize citronellyl acetate via transesterification of citronellol and vinyl acetate [28]. The results showed that 99.8% conversion could be achieved after 12 h at 37 • C and 160 rpm.…”

Synthesis of citronella acetate by lipase catalyzed transesterification in ionic liquid and its kinetics

“…Jian XIONG 1# * , Wenyuan SUN 1# , Hanghang XU 1 , Jinhui BIAN 2 , Yafei SONG 1 , Shengwei PAN 1 , Jiayu GAO 1 At present, there are few reports about the lipase-catalyzed synthesis of citronellyl acetate in non-aqueous solvents. Yuan et al (2022) based on the activation mechanism of lipase at the water/oil (organic phase) interface, inexpensive raceme straw was processed into powder and filaments on which Pseudomonas fluorescens lipase was immobilised by physical adsorption to synthesise citronellol via ester exchange of citronellol and vinyl acetate. The results showed that 99.8% conversion could be achieved after 12 hours at 37 °C and 160 r/min.…”