Promotion of Biotransformation from Isoeugenol to Vanillin by Lysinibacillus Fusiformis with Sol-gel Chitosan Membrane

The chitosan membrane was prepared by a sol-gel freeze-drying method and used to remove the produced vanillin in time from the biotransformation system of isoeugenol to vanillin by Lysinibacillus fusiformis CGMCC1347. The chitosan and vanillin could be linked by the formed schiff bases. The combining and eluting conditions were optimized. As a result, 1 g chitosan membrane could combine 0.125 g vanillin under the condition of p H 7.0, 37 oC, and 200 r/min in 48 h. All the combined vanillin could be eluted from the chitosan membrane with 6.17%(w/w) aqueous HCl at room temperature in 10 h. The product inhibition could be avoided by the addition of chitosan membrane during the biotransformation. The optimal biotransformation conditions are 2%(v/v) isoeugenol, 0.48 g wet cells, 0.1 g chitosan membrane, 50 mmol/L phosphate buffer(p H 8.0), 37 oC, 180 r/min for 60 h in 10 m L reaction liquid in 50 m L flask and the highest vanillin concentration reaches 1.71 g/L.