Wang Le, Tang Pingwah, Fan Xiaoguang, Yuan Qipeng
State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, 100029, Beijing, China; College of Bioengineering, Henan University of Technology, 450000, Zhengzhou, China.
Biotechnol Prog. 2013 Sep-Oct;29(5):1181-9. doi: 10.1002/btpr.1774. Epub 2013 Jul 11.
The effects of four aldehydes (furfural, 5-hydroxymethylfurfural, vanillin and syringaldehyde), which were found in the corncob hemicellulose hydrolysate, on the growth and xylitol fermentation of Candida tropicalis were investigated. The results showed that vanillin was the most toxic aldehyde for the xylitol fermentation, followed by syringaldehyde, furfural and 5-hydroxymethylfurfural. Moreover, the binary combination tests revealed that furfural amplified the toxicity of other aldehydes and the toxicities of other binary combinations without furfural were simply additive. Based on the fermentation experiments, it was demonstrated that the inhibition of aldehydes could be alleviated by prolonging the fermentation incubation, increasing the initial cell concentration, enhancing the initial pH value and minimizing the furfural levels in the hydrolysate evaporation process. The strategies that we proposed to suppress the inhibitory effects of the aldehydes successfully avoided the complicated and costly detoxifications. Our findings could be potentially adopted for the industrial xylitol fermentation from hydrolysates.
研究了在玉米芯半纤维素水解物中发现的四种醛（糠醛、5-羟甲基糠醛、香草醛和丁香醛）对热带假丝酵母生长和木糖醇发酵的影响。结果表明，香草醛对木糖醇发酵毒性最大，其次是丁香醛、糠醛和5-羟甲基糠醛。此外，二元组合试验表明，糠醛会放大其他醛的毒性，而不含糠醛的其他二元组合的毒性只是简单相加。基于发酵实验，结果表明，通过延长发酵培养时间、提高初始细胞浓度、提高初始pH值以及在水解物蒸发过程中尽量降低糠醛水平，可以减轻醛的抑制作用。我们提出的抑制醛抑制作用的策略成功避免了复杂且昂贵的解毒过程。我们的研究结果可能会被应用于工业水解物木糖醇发酵。
