Microbial Transformation Of Ferulic Acid To Vanillin

A new technology of transforming ferulic acid, which was from waste residue of rice bran oil, into vanillin was developed by a combination of fungal strains Aspergillus niger CGMCC0774 and Pycnoporus cinnabarinus CGMCC1115.Ferulic acid was hydrolyzed from waste residue of rice bran oil, and was used as the source of vanillin production. By irradiated A. niger SW-33 with 60Co radial, a strain A. niger CGMCC0774, which could tolerance high substrate, was screened. 2.481 g/L of vanillic acid with a molar yield of 71.62% was obtained. The conditions of ferulic acid to vanillic acid were studied, and the optimal conditions were: bioconversion temperature of 37℃, shaking speed of 150 r/min, ferulic acid concentration of 4 g/L, 140 mL shaking flask loading in 250 mL shaking flask. 2.24 g/L of vanillic acid with a molar yield of 64.6% was produced through feeding substrate by A. niger CGMCC0774 in a 25 L fermenter.The filtrate of A. niger CGMCC0774 culture was adjusted to pH5.0, adding 5 g/L of glucose, sterilized and bio-converted into vanillin by P. cinnabarinus CGMCC1115 free cells with 0.63 g/L of vanillin produced. The integrated reaction seperation process of P. cinnabarinus CGMCC1115 was studied. 2.20 g/L of vanillin with a molar yield of 60.69% was obtained when vanillic acid concentration was 4 g/L and added 20 g of HZ802 resin in the bioconversion medium.The 13C isotope analysis indicated thatδ13CPDB of vanillin prepared from waste residue of rice bran oil was much different from chemically synthesized vanillin, and was identical with natural vanillin from Rhovanil? Natural.The immobilized cells of P. cinnabarinus were researched, and 0.499 g/L of vanillin was produced at 72 h. After immobilized cells were used four times, vanillin yield was obviously decreased. The research on immobilized cells of P. cinnabarinus would be further studied.