Solid-State Fermentation with Streptomyces as an Ecofriendly
发布日期：2026-02-09 23:34 浏览次数：
The herein work analyzes the compositional and structural modification of extracted lignins from both barley and wheat straws biologically pretreated with Streptomyces by solid-state fermentation with two different strains, MDG147 and MDG301. The results showed that the MDG301 strain promoted major lignin solubilization, especially for wheat straw and alkaline extraction, and simultaneously exhibited a higher hydrolytic enzymatic profile than MDG147. Furthermore, the substrates were submitted to soda pulping, and the chemical composition and structural characteristics of the extracted soda-lignins were analyzed by analytical standard methods, Fourier transform infrared spectroscopy, thermogravimetric analysis, and nuclear magnetic resonance. Generally, soda-lignins showed high purity, with the remaining carbohydrate content in agreement with enzymatic patterns. Moreover, Streptomyces strains produced structural modifications, including a major degradation of β-alkyl-aryl ether and C–C linkages of soda-lignins, as well as an enrichment of syringyl units. Furthermore, these modifications also increased the hydroxyl group content, increasing entanglement possibilities and H-bonding. The obtained soda-lignins were focused on as binders for the adhesive formulation, showing excellent adhesion results. Those adhesives based on lignin coming from barley straw exhibited the best performance in shear strength tests, whereas those extracted from wheat straw provided the maximum values in peeling essays.
本研究分析了链霉菌（Streptomyces）两株菌MDG147和MDG301固态发酵生物预处理后，大麦秸秆和小麦秸秆提取木质素的组成与结构变化。结果表明，MDG301菌株显著促进了木质素的溶出，尤其对小麦秸秆及碱提取体系效果更为突出，同时表现出优于MDG147的水解酶活性谱。进一步将预处理原料进行苏打制浆，采用标准分析方法、傅里叶变换红外光谱（FTIR）、热重分析（TGA）及核磁共振（NMR）对所提取苏打木质素的化学组成与结构特征进行系统表征。总体而言，苏打木质素纯度较高，残余碳水化合物含量与酶学分析结果相吻合。此外，链霉菌预处理引起了木质素结构修饰，包括苏打木质素中β-烷基-芳基醚键和C–C键的显著断裂，以及紫丁香基（syringyl）单元的富集。上述结构变化还增加了羟基含量，从而增强了分子链缠结能力和氢键作用。所得苏打木质素作为胶粘剂配方中的粘合剂组分进行了性能评价，表现出优异的粘接效果。其中，源于大麦秸秆的木质素基胶粘剂在剪切强度测试中表现最佳，而源于小麦秸秆的胶粘剂则在剥离试验中呈现最高数值。
