Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China.
Carbohydr Polym. 2019 Jul 15;216:369-375. doi: 10.1016/j.carbpol.2019.04.018. Epub 2019 Apr 5.
Lignocellulosic-like materials are potentially low-cost fermentation substrates, but their pretreatment brings about by-products. This work investigated the effects of furfural on xanthan gum (XG) production, and product quality was evaluated by structure, viscosity and antioxidant capacities. Xanthomonas campestris maintained steady polysaccharide yield (above 13 g·L) with enhanced cell growth at low furfural concentrations (below 3.2 g·L). The products were verified as XG by FT-IR, XRD, NMR and monosaccharide analysis. Moreover, they were found to have reduced acetyl, rising pyruvate and up-to-down glucuronic acid groups as increasing furfural concentration. Furthermore, XG product with 1 g·L furfural addition showed the best hydroxyl scavenging effects, though reducing powers presented no variation. It was demonstrated that furfural, the common hydrolysis by-product, was not necessarily an inhibitor for fermentation, and an appropriate amount of furfural was beneficial to XG production with steady yield and good quality.
木质纤维素样材料是具有成本效益的潜在发酵基质，但它们的预处理会带来副产物。本研究考察了糠醛对黄原胶（XG）生产的影响，并通过结构、黏度和抗氧化能力评估了产物质量。在低浓度糠醛（低于 3.2 g·L）下，木杆菌保持了稳定的多糖产量（高于 13 g·L），同时促进了细胞生长。通过傅里叶变换红外光谱（FT-IR）、X 射线衍射（XRD）、核磁共振（NMR）和单糖分析验证了产物为 XG。此外，随着糠醛浓度的增加，发现产物的乙酰基减少，丙酮酸增加，葡萄糖醛酸基团先增加后减少。此外，添加 1 g·L 糠醛的 XG 产物具有最佳的羟基清除效果，尽管还原力没有变化。结果表明，糠醛是常见的水解副产物，它不一定是发酵的抑制剂，适量的糠醛有利于稳定产率和良好质量的 XG 生产。
