复合菌群协同发酵烟梗的降解特性及微生物多样性研究

Study on degradation characteristics and microbial diversity of tobacco stem by synergistic fermentation with microbial community

采用枯草芽孢杆菌(Bacillus subtilis)与植物乳杆菌(Lactobacillus plantarum)复合发酵烟梗,研究复合菌群固态厌氧发酵前后烟梗细胞壁成分的变化、烟梗的结构性质和热解反应特性、致香成分及细菌群落结构的变化。结果表明:发酵5 d烟梗中木质素降解率达到50.55%,复合菌群主要通过断裂木质素与半纤维素之间的共价键、甲氧基脱甲基化、苯环开环等过程,增强对木质素的降解作用;复合菌群固态厌氧发酵更有利于烟梗热解反应的进行,发酵5 d烟梗的热解失重率增加了4.85%,最大热解反应速率提高了13.28%;发酵5 d烟梗中总致香成分含量提高了7.88%,其中类胡萝卜素降解产物总量提升效果显著;除枯草芽孢杆菌与植物乳杆菌外,与木质素降解相关功能菌群的相对丰度显著增加,多菌群协同作用增强了烟梗中木质素的降解转化。

The bacterial community composed by Bacillus subtilis and Lactobacillus plantarum was used to ferment tobacco stem, the degradation of cell wall components, the structural properties and thermal reaction characteristics, the changes of aroma components and bacterial community structure of tobacco stem by solid-state anaerobic fermentation were studied. Results showed that after 5 days of anaerobic fermentation, the degradation rate of lignin in tobacco stem was 50.55%. Degradation of lignin was enhanced mainly by the breakdown of covalent bond between lignin and hemicellulose, demethylation, benzene ring decomposition, etc. After anaerobic fermentation, the pyrolysis weight loss of tobacco stem was increased by 4.85% and the maximum pyrolysis rate was increased by 13.28%, which was more conducive to the pyrolysis reaction. The content of total aroma components in tobacco stem after fermentation was increased by 7.88%, and the content of degraded carotene products increased significantly. In addition to Bacillus subtilis and Lactobacillus plantarum, the relative abundance of functional bacteria related to lignin degradation was greatly increased, and the degradation and transformation of tobacco stem lignin was improved by the synergistic fermentation with microbial community.