Tuesday, May 3, 2011
Majority of vanillin (4-hydroxy-3-methoxybenzaldehyde) supplied to the world market today is chemically synthesized from a petroleum-based raw material, raising an increasing concern among the consumers regarding to the product safety. In this research, an organic solvent-tolerant Brevibacillus agri 13 previously reported for a strong predilectic property was utilized as a whole-cell biocatalyst for bioproduction of vanillin from isoeugenol, an economical starting material from clove oil. In order to obtain a large amount of biomass required for a whole-cell bioconversion process, growth medium was optimized using statistical designs like Plackett-Burman and a response surface method (RSM). Also, an extreme level of organic solvent tolerance of Br. agri 13 allowed us to utilize it in a biphasic system using organic solvents generally considered as highly toxic to most bacteria. In this study, an addition of butyl acetate at 30% (v/v) as an organic second phase significantly reduced the toxicity of isoeugenol exerted onto the resting cells as well as resulted in higher vanillin production.