蔬菜废弃物堆肥中耐高温菌QK降解木质纤维素的特征

Characteristics of lignocellulose degradation by thermotolerant bacteria QK in vegetable waste composting

为探究添加微生物对好氧堆肥中木质纤维素降解特征,本研究以番茄、甜瓜蔬菜废弃物为原料,设置不添加菌剂对照组CK和添加自主筛选的耐55℃高温芽孢杆菌QK进行高温好氧堆肥试验,采集0、7、15和31 d样品分析木质纤维素含量、酶活性以及微生物多样性,探究蔬菜废弃物堆肥中耐高温菌QK降解木质纤维素的特征。结果表明,添加QK对纤维素、半纤维素、木质素的降解率分别为65.14%、58.28%、48.51%,较CK提高了8.27%、7.26%、15.21%。添加QK提升了羧甲基纤维素酶、半纤维素木聚糖酶、木质素过氧化物酶、锰过氧化物酶、漆酶活性,较CK显著提升22.64%、25.46%、50%、186.25%、61.70%。添加QK改变了细菌和真菌群落结构及多样性,其Shannon指数均得到显著提高,增加促进木质纤维素降解的拟诺卡氏菌属(Nocardiopsis)、短杆菌属(Brachybacterium)等相对丰度,同时降低病原菌棒杆菌属(Corynebacterium)、气球菌属(Aerococcus)相对丰度。耐高温芽孢杆菌QK的表现特征掲示它可以作为堆肥的良好促腐菌剂,并为解析木质纤维素降解转化机制提供了理论依据。

This study explored the degradation characteristics of lignocellulose by adding microorganisms to aerobic composting.Tomato and melon vegetable wastes were used for high temperature aerobic composting with adding 55°C temperature tolerant bacillus QK and without bacterial agent as the CK group.Samples were collected on 0 day,7 day,15 day and 31 day to analyze lignocellulose content,enzyme activity and microbial diversity.The results showed that the degradation rates of cellulose,hemicellulose and lignin by adding QK were 65.14%,58.28%and 48.51%,which were 8.27%,7.26%and 15.21%higher than those of the control.The addition of QK significantly increased the activities of carboxymethyl cellulase,hemicellulose xylanase,lignin peroxidase,manganese peroxidase and laccase by 22.64%,25.46%,50%,186.25%and 61.70%compared with the control,respectively.The community structure and diversity of bacteria and fungi were changed by the addition of QK.The Shannon index was significantly increased.The relative abundance of Nocardiopsis and Brachybacterium that promoted lignocellulose degradation was increased.While the relative abundance of pathogenic bacteria Corynebacterium and Aerococcus was decreased.The characteristics of heat-resistant bacteria QK showed that it could be used as a good rot-promoting agent for composting.This study provided a theoretical basis for analyzing the degradation and transformation mechanism of lignocellulose.