Biotransformation Of Isoeugenol To Vanillin By Microorganisms

As one of the most important components of natural flavours, vanillin (4-hydroxy-3- methoxybenzaldehyde) is widely used in foods, beverages, perfumes, pharmaceuticals and medical industries. Natural vanillin extracted from vanilla pods features both a high price and a limited supply. The increasing concern for health and nutrition and the limit of chemistry food additive in USA and EU stimulate a worldwide demand for natural vanillin.Biotransformation is an alternative or equivalent technology to get natural vanillin. Natural isoeugenol from essential oil are the available and economical substrate for the vanillin production. Therefore, the bioconversion of isoeugenol to vanillin becomes more and more attractive.This paper focused on the biotransformation of isoeugenol to vanillin by microorganisms. After the isolation of Bacillus sp. SW-B9 from soil, its physiological, biochemical characteristics and the 16S rDNA were analyzed. Condition optimization for its efficient fermentation was also carried out. The reaction and separation system with the addition of resin HD-8 and the isoeugenol/aquoeus biphasic system of the biotransformation of isoeugenol to vanillin by Bacillus fusiformis CGMCC1347 were set up. The isolation and purification of isoeugenol and vanillin in both systems were studied. The reuse of the immobilized cells in biphasic system was successfully applied.The biotransformations of isoeugenol to vanillin with various strains available in our lab were tested. It was found that several baterica including Bacillus subtilus 7658, Alcaligenes AS1.7617, Brevibacterium flavum 1.7a and Brevibacterium flavum AS1.013 could convert isoeugenol to vanillin. The maximum vanillin concentration was 0.31 g/L. Nocardia sp. 33, Nocardia tartic 58, Nocardia sp. 56, Nocardia sp. 44 and Nocardia sp. 13-1.58 could produce 0.12 g/L~0.63 g/L vanillin. Some other fungi yielding vanillin were Saccharomyces cerevisiae 4.1, yeast16-7, 2.16-8, 2.21f, 2.21h and yeast SW-57.14 strains beneficial to transform isoeugenol to vanillin were isolatied from soil based on the screening model using high concentration of isoeugenol. Strain SW-B9 could produce 1.10 g/L vanillin from 2% (v/v) isoeugenol and its degrading capacity of vanillin was weak. Among the strains avaible in lab and isolatied from soil, Bacillus sp. SW-B9 was selected for further study due to its highest vanillin production ability.According to physiological and biochemical characteristics of strain SW-B9 and the 16S rDNA gene sequence analysis, strain SW-B9 was identified as a kind of Bacillus fusiformis. The sequence data has been assigned accession number AY907676 in the GenBank database. Strain SW-B9 was conserved in China General Microbiological Culture Collection Center...