Abstract：
Pre-hydrolysate liquor, as an inevitable by-product, contains a large amount of xylose, and is therefore an inexpensive feedstock that can be upgraded to value-added chemical xylonic acid. However, inhibitors, simultaneously formed in lignocellulose pretreatment process, are regarded as the major obstacle for effectively bio-converting xylose in pre-hydrolysate into xylonic acid. In this study, Gluconobacter oxydans, with highly selective and efficient, was employed for xylonic acid production; the impacts of five typical toxic inhibitory compounds on xylonic acid productivity and the activity of the membrane-bound dehydrogenase were evaluated. The results revealed that the inhibitors showed different degrees of influence toward xylonic acid production, and the order of inhibitory effect for acidic inhibitors was formic acid > acetic acid > levulinic acid; the inhibitory effect of aldehyde inhibitors was furfural > 5-hydroxymethyl-furfural. This study provides an important basis of metabolic modification and detoxification process for enhancing inhibitor tolerance and xylonic acid productivity.
摘要：
预水解液,作为不可避免的副产品，含有大量的木糖,因此是一种廉价的原料，可以升级为增值的化学木糖酸。然而,抑制剂，在木质纤维素预处理过程中同时形成，被认为是有效地将预水解产物中的木糖生物转化为木糖酸的主要障碍。在这项研究中,氧化葡糖杆菌,具有高度选择性和高效，用于木质酸生产；评估了五种典型的毒性抑制化合物对木质酸生产率和膜结合脱氢酶活性的影响。结果表明，抑制剂对木糖酸的生产有不同程度的影响，酸性抑制剂的抑制作用顺序为甲酸>乙酸>乙酰丙酸；醛抑制剂的抑制作用为糠醛>5-羟甲基糠醛。本研究为提高抑制剂耐受性和木质酸生产率提供了代谢修饰和解毒过程的重要依据。
