摘要
北方高寒地区温度低、气候干燥等环境条件会使秸秆、牛羊粪等纤维素类物质的原位还田和当季降解缓慢,造成下一年耕作困难、播种质量低.为提高北方高寒地区纤维素类物质的降解效率,通过室内培养试验,选择高寒草原地区矿区土壤与具有较好纤维素降解能力的菌剂作为菌源,以玉米秸秆中的纤维素类物质为降解对象,采用富集培养和温度梯度驯化方法筛选出耐低温(15℃)高效降解纤维素的复合菌系,明确其纤维素类物质降解特性及菌系组成多样性.结果表明:复合菌系SL15(以矿区土壤为菌源)、MM15(以纤维素降解菌剂为菌源)和MS15(以矿区土壤添加纤维素降解菌剂为菌源)在15℃下培养15 d纤维素类物质降解率分别为22.33%、26.33%和29.23%.其中复合菌系MS15对纤维素类物质的降解能力最强,滤纸酶和内切酶活性最高分别可达4.6925和2.2267 U/mL.由高通量测序可知,变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)、子囊菌门(Ascomycetes)和担子菌门(Basidiomycetes)为各复合菌系的优势菌门,鞘氨醇杆菌属(Sphingobacterium)、金黄杆菌属(Chryseobacterium)和布鲁氏菌属(Brucella)等共同促进纤维素类物质的降解,鞘氨醇杆菌属和担子菌门中的菌属作为复合菌系MS15中的优势菌群,显著增强了纤维素降解酶活性及纤维素类物质降解率.研究显示,筛选过程在富集了耐低温纤维素降解菌的同时淘汰了无关菌属,将外源纤维素降解菌剂加入土著微生物群落增强了微生物活性,显著提高了纤维素类物质的降解率,可为进一步开发纤维素降解复合菌系、促进低温条件下玉米秸秆等纤维素类物质原位还田提供技术支撑.
Environmental conditions such as low temperature and dry climate in the northern alpine region will make the in-situ degradation of cellulose substances such as straw,cattle and sheep manure slow,resulting in difficult cultivation and low seeding quality in the next year.In order to improve the degradation efficiency of cellulose substances in the northern alpine region,the soil at a mining area in the alpine grassland area and the microbial agent with good cellulose degrading ability were selected as the bacterial source materials through the laboratory culture experiments.Cellulose substances in corn straw were taken as the degradation objects.Enrichment culture and temperature gradient acclimation methods were used to select the complex bacteria that were resistant to low temperature(15℃)and efficient in degrading cellulose.The degradation characteristics of cellulose substances and the diversity of complex bacteria composition were determined.The results show that the cellulose degradation rates of SL15(the bacteria source is the soil of mining area),MM15(the bacterial source is cellulose degrading bacterial agent)and MS15(the bacteria source is the soil of mining area with added cellulose degrading bacteria agent)were 22.33%,26.33%and 29.23%,respectively,when they cultured at 15℃for 15 days.The composite strain MS15,which was selected by adding exogenous cellulose degrading bacteria from indigenous microorganisms,had the strongest cellulose degrading ability,and the highest filter paper enzyme activity and endonuclease activity,which were 4.6925 U/mL and 2.2267 U/mL,respectively.High-throughput sequencing revealed that Proteobacteria,Bacteroidetes,Firmicutes,Ascomycetes and Basidiomycetes were the dominant phyla in all complex bacteria.Sphingobacterium,Chryseobacterium,and Brucella all promoted the degradation of cellulose.Sphingobacterium and Basidiomycota were the dominant bacteria in MS15,which significantly enhanced the activity of cellulose degrading enzymes and the degradation rate of cellulose sub
作者
颜淑慧
孟庆俊
许瑞
李晟楠
王立艳
焦扬
宋超
YAN Shuhui;MENG Qingjun;XU Rui;LI Shengnan;WANG Liyan;JIAO Yang;SONG Chao(School of Environment Science and Spatial Informatics,China University of Mining and Technology,Xuzhou 221116,China;ZALAINUOER Coal Mine Co.,Ltd.,Manzhouli 021400,China)
出处
《环境科学研究》
CAS
CSCD
北大核心
2023年第7期1404-1415,共12页
Research of Environmental Sciences
基金
中国华能集团有限公司科技项目(No.HNMYKJ20-08)。
关键词
低温
纤维素
降解
复合菌系
筛选
low-temperature
cellulose
degradation
complex bacteria
screen
