摘要
对呼伦贝尔森林土壤中的常温纤维素降解细菌进行筛选,将酶活性高的菌株分别混合构建降解复合系并测定其滤纸降解能力。分别以微晶纤维素、CMC和D-水杨苷3种不同的底物为碳源在25℃下筛选纤维素降解细菌,以16S rDNA序列进行菌株的鉴定和系统发育分析,用DNS法测定单菌株的外切葡聚糖酶、内切葡聚糖酶和β-葡萄糖苷酶的酶活性和复合系的滤纸酶活性。结果共分离到258株常温纤维素降解细菌,以微晶纤维素为底物分离到的细菌分属于5个纲,以CMC或D-水杨苷为底物分离到的细菌分属于6个纲,第一优势菌纲均为γ-Proteobacteria;其次为α-Proteobacteria;第一优势菌属均为假单胞菌属(Pseudomonas),其次为根瘤菌属(Rhizobium)、厄氏菌属(Oerskovia)、芽孢杆菌属(Bacillus)和Lelliottia。构建的27个常温降解复合系中滤纸酶活性最高的降解复合系为C11′3″、C32′2″和C33′2″,酶活性分别为200.60、200.05和208.79 U/mL,是复合系中单独菌株的6~10倍,滤纸降解率分别为26.8%、22%和32.4%。C11′3″、C32′2″和C33′2″为常温降解复合系最优菌群组合,具有较高的应用潜力。
The room temperature cellulose-degrading bacteria were screened from the forest soil of Hulunbeier city. The strains of high enzyme activity were separately mixed to construct room temperature cellulose-degrading consortia, and filter paper degradation abilities were measured, using three different substrates(avicel, CMC and D-salicin) as carbon source respectively to isolate cellulose-degrading bacteria at 25 ℃. The 16 S rDNA sequence was used for identification and phylogenetic analysis of strains, and DNS method was used to determine the enzyme activity of exogenous glucanase, endogenous glucanase and β-glucanase of the isolated strains, as well as the filter paper enzyme activity of the cellulose-degrading consortia. As a result, 258 room temperature cellulose-degrading bacteria were isolated. Among them, the bacteria isolated with avicel as substrates belong to five classes, and the bacteria isolated with CMC or D-salicin as substrates belong to six classes. The first dominant class was γ-Proteobacteria, and the second dominant class was α-Proteobacteria. The first dominant genera was Pseudomonas, followed by Rhizobium, Oerskasty, Bacillus and Lelliottia. In 27 cellulose-degrading consortia, C11′3″, C32′2″ and C33′2″ had the highest filter paper enzyme activity, and the enzyme activity was 200.60, 200.05 and 208.79 U/mL, respectively, which is 6-10 times more than the filter paper enzyme activity of single strain in its consortia. The degradation rate of filter paper was 26.8%, 22% and 32.4%, respectively. In conclusion, C11′3″, C32′2″ and C33′2″ are optimal flora combination of cellulose-degrading consortia, which have higher application potential.
作者
孟建宇
冀锦华
郭慧琴
陶羽
冯福应
赵鸿彬
MENG Jian-yu;JI Jin-hua;GUO Hui-qin;TAO Yu;FENG Fu-ying;ZHAO Hong-bin(Institution for Applied and Environmental Microbiology of Life Sciences College,Inner Mongolia Agricultural University,Hohhot 010011,China)
出处
《生物学杂志》
CAS
CSCD
北大核心
2020年第3期86-90,共5页
Journal of Biology
基金
国家自然科学基金项目(31460002,31760154)
内蒙古自治区自然科学基金项目(2018MS03042)。
关键词
常温纤维素降解菌
降解复合系
滤纸酶活
碳源
room temperature cellulose-degrading bacteria
degradation consortia
filter paper enzyme activity
carbon source
