Department of Biotechnology, College of Chemical Engineering of Lorena, PO Box 116, Lorena, São Paulo, Brazil.
Bioresour Technol. 2010 Mar;101(6):1858-65. doi: 10.1016/j.biortech.2009.09.072. Epub 2009 Oct 12.
The effect of lignin degradation products liberated during chemical hydrolysis of lignocellulosic materials on xylose-to-xylitol bioconversion by Candida guilliermondii FTI 20037 was studied. Two aromatic aldehydes (vanillin and syringaldehyde) were selected as model compounds. A two-level factorial design was employed to evaluate the effects of pH (5.5-7.0), cell concentration (1.0-3.0 g l(-1)), vanillin concentration (0-2.0 g l(-1)) and syringaldehyde concentration (0-2.0 g l(-1)) on this bioprocess. The results showed that in the presence of vanillin or syringaldehyde (up to 2.0 g l(-1)) the cell growth was inhibited to different degrees with a complete inhibition of the yeast growth when the mixture of both (at 2.0 g l(-1) each) was added to the fermentation medium. The xylitol yield was not significantly influenced by vanillin, but was strongly reduced by syringaldehyde, which showed a more pronounced inhibitor effect at pH 7.0. The yeast was also able to convert vanillin and syringaldehyde to the corresponding aromatic acids or alcohols and their formation was dependent of the experimental conditions employed.
研究了木质纤维素材料化学水解过程中释放的木质素降解产物对毕赤酵母 FTI 20037 转化木糖为木糖醇的影响。选择两种芳香醛（香草醛和丁香醛）作为模型化合物。采用两因素析因设计来评估 pH（5.5-7.0）、细胞浓度（1.0-3.0 g/L）、香草醛浓度（0-2.0 g/L）和丁香醛浓度（0-2.0 g/L）对该生物过程的影响。结果表明，在添加浓度高达 2.0 g/L 的香草醛或丁香醛时，细胞生长受到不同程度的抑制，当混合物（每种 2.0 g/L）添加到发酵培养基中时，酵母生长完全受到抑制。香草醛对木糖醇的产率没有显著影响，但丁香醛强烈抑制了木糖醇的生成，在 pH 7.0 时表现出更明显的抑制作用。酵母还能够将香草醛和丁香醛转化为相应的芳香酸或醇，其形成取决于所采用的实验条件。
