耐低温降解纤维素菌株的筛选及复合菌系构建  

Screening of Low Temperature Cellulose Degradation Strains and Construction of Complex Microbial System

作　　者：路垚 刘雅辉[2] 孙建平[2] 何宗均[1] 赵琳娜 戴相林 赵子婧 LU Yao;LIU Ya-hui;SUN Jian-ping(Institute of Agricultural Resources and Environment Sciences,Tianjin Academy of Agricultural Sciences,Tianjin 300384;Institute of Coastal Agriculture,Hebei Academy of Agriculture and Forestry Sciences,Tangshan,Hebei 063299)

机构地区：[1]天津市农业科学院农业资源与环境研究所,天津300384 [2]河北省农林科学院滨海农业研究所,河北唐山063299

出　　处：《安徽农业科学》2022年第10期6-10,27,共6页Journal of Anhui Agricultural Sciences

基　　金：河北省省级科技计划项目(19227307D);天津市农业科技成果转化与推广项目(201701090)。

摘　　要：[目的]筛选适合我国北方冬春季秸秆降解的高效低温纤维素降解菌株。[方法]在低温地区采集土壤,10℃初筛耐低温菌株,通过刚果红染色液法进行复筛,利用DNS法测定CMC酶活性。将筛得菌株和实验室自存菌株结合拮抗试验构建复合菌系,测定复合菌系CMC酶活性,测定秸秆降解率,并对代表性菌株进行产酶条件优化,对最终确定的复合菌系中的菌株进行分子生物学鉴定。[结果]10℃低温培养初筛得到55株耐低温菌株,刚果红染色法复筛得到8株具有明显水解圈的单菌株,其中包括细菌3株、真菌2株、放线菌3株,其中纤维素酶活性最高达到47.0 U/mL;根据拮抗试验构建了2个复合菌系,其纤维素酶活性分别达到31.0和53.0 U/mL;秸秆降解试验中,实验室和沙袋法的复合菌系2对秸秆的降解率分别达31.8%和45.1%,显著高于复合菌系1和对照组;对JGDZTX3进行产酶条件优化,确定最佳氮源为牛肉膏,培养温度为10℃,培养时间为4 d,初始pH为7,在此条件下CMC酶活性达到66.5 U/mL,这4个条件对产酶均有显著影响(P<0.05);对复合菌系2的4个未知菌株进行鉴定,鉴定结果分别为白蚁菌、葡萄球菌、长柄木霉、芬莱氏链霉菌。[结论]通过该试验筛选得到的耐低温可降解纤维素复合菌系有较强的纤维素分解能力,在北方低温地区有良好的应用前景。[Objective] In order to screen the high efficiency low temperature cellulose degradation strains suitable for winter and spring straw degradation in north China. [Method]Soil samples were collected in low temperature area, low temperature strains were screened at 10 ℃, the isolated strains were screened by Congo red staining solution, and CMC enzyme activity was determined by DNS method. The complex microbial system was constructed by combining the screened strain and the laboratory self-existing strain with antagonistic test. CMC enzyme activity of the complex microbial system was determined, and the straw degradation rate was determined. The enzyme production conditions of the representative strain was optimized, and the strains in the final determined complex microbial system were identified by molecular biology. [Result]A total of 55 low temperature strains were obtained by initial screening at 10 ℃, and 8 strains were obtained by Congo red staining after screening, including 3 strains of bacteria, 2 strains of fungi and 3 strains of actinomycetes with obvious hydrolytic circles. The highest cellulase activity reached 47.0 U/mL. According to the antagonistic test, the cellulase activity of two complex microbial systems reached 31.0 and 53.0 U/mL, respectively. In the straw degradation test, the degradation rates of the compound strain 2 in the laboratory and the sandbag method were 31.8% and 45.1%, respectively, which were significantly higher than those of the compound strain 1 and the control group.The optimum conditions for JGDZTX3 enzyme production were optimized, and the optimal nitrogen source was beef paste, culture temperature was 10 ℃, culture time was 4 d, and initial pH was 7. Under the optimum conditions, CMC enzyme activity reached 66.5 U/mL,all the four conditions had significant effects on enzyme production(P< 0.05).The four unknown strains of the complex microbial system were identified, and the identification results were Isoptericola sp., Staphylococcus sp., Trichoderma longibrachiatum

关 键 词：纤维素降解菌 复合菌系 低温 纤维素酶 筛选 菌株鉴定 

分 类 号：S182[农业科学—农业基础科学]