玉米秸秆低温高效降解复合菌系GF-20的筛选及其特性研究

发布时间：2018-02-14 17:03

本文关键词： 玉米秸秆降解低温复合菌系菌种组成稳定性　出处：《内蒙古农业大学》2016年博士论文　论文类型：学位论文

【摘要】：我国玉米秸秆资源非常丰富,但目前对其利用很不充分。秸秆还田可以提高土壤养分,实现农业生产的可持续发展。但在我国北方春玉米区秋收后低温等气候因素限制还田秸秆的当季腐解,秸秆在土壤中腐解转化的时间较长,不仅不能作为当季作物的肥源还会影响后季作物播种质量。为加快原位还田玉米秸秆的分解速率,提高腐解质量,本研究从低温(年平均气温-7℃-8℃)生态环境中采集长年秸秆还田土壤、牛羊粪、腐烂树叶等样品为菌源材料,通过富集培养、碳源限制性继代培养与低温驯化等过程,筛选低温条件(4℃～10℃)下高效降解玉米秸秆的复合菌系,并明确其秸秆分解特性、菌种组成特性、稳定性和适应性以及应用效果,为北方地区低温条件(4℃～10℃)下玉米秸秆快速、高效腐解以及合理利用提供理论依据,并提供菌株资源。主要研究结果如下：1.玉米秸秆低温高效降解复合菌系的筛选：利用富集培养、限制性继代培养、低温逐代驯化等技术对128份采集于高寒地区玉米秸秆还田土壤、牛羊粪、腐烂树叶等菌源材料进行筛选,获得7个低温(10℃)、中温(15℃)双高效型菌系和20个低温(10℃)高效型菌系。进一步通过对不同代数菌系玉米秸秆降解率及纤维素酶活性动态分析,最终获得一组可在低温条件(4℃～10℃)下高效产纤维素酶,并稳定降解玉米秸秆的复合菌系GF-20,其在接种后12h内进入对数生长期,分泌纤维素酶,分解玉米秸秆成简单酯类或烃类。在10℃低温条件下培养15d,玉米秸秆降解率达到32.29%,较对照复合菌系No.8(本研究小组2013年筛选,温度15℃条件下降解率为22.02%)高出10.27%。2.玉米秸秆低温高效降解复合菌系菌种组成多样性：复合菌系GF-20由22种细菌和4种真菌组成。细菌组成分别为Azonexus hydrophilus、Azospira oryzae、Variovorax boronicumulans、Hydrogenophaga caeni、Herbaspirllum frisingense、Arcobacter cloacae、 Pseudomonas fuscovaginae、Cellvibrio mixtus subsp.mixtus、Seleniivibrio woodruffii、 Rhodococcus qingshengii、Terribacillus saccarophilus、Planococcus antarcticus、Bacillus licheniformis、Bacillus tequilensis、Clostridium populeti、Clostridium xylanolyticum、 Paludibacter propionicigenes、Pedobacter agri、Sphingobacterium cladoniae和Uncultured bacterium等。真菌主要为Lotharella globosa、Trichosporon sp.、Trichosporon loubieri和Chlamydomonas leiostraca。3.玉米秸秆低温高效降解复合菌系稳定性及适应性：复合菌系GF-20在分解玉米秸秆过程中区系变化较稳定,关键菌株稳定存在；在不同温度(4℃-30℃)和pH值(6.0-9.0)条件下继代培养、在变温条件(0℃-40℃)下连续培养,复合菌系性质、功能与组成均保持稳定,具有较强的稳定性和适应性；碳源为玉米秸秆、氮源为硫酸铵时复合菌系GF-20菌种组成更稳定,诱导复合菌系产纤维素酶,促进底物分解；复合菌系GF-20的临界稀释梯度为1014倍。4.玉米秸秆低温高效降解复合菌系应用：在接种量10%、pH值6.5、玉米秸秆和硫酸铵添加比40：1、温度10℃、渗透压浓度2.0%条件下发酵制成的腐解菌剂GF-20具有良好的促分解效果。在4℃、10℃和30℃条件下腐解60d,玉米秸秆降解率分别为29.00%、36.75%和59.47%,较对照绿康菌剂高出7.21%、9.78%和10.26%；碱解氮、有效磷、速效钾和有机质含量分别增加0%-5.32%、5.26%-14.17%、2.07%-3.57%和0.44%～2.94%；显著提高土壤过氧化氢酶、脲酶、碱性磷酸酶、蔗糖酶、B-葡萄糖苷酶和纤维素酶活性；增加土壤微生物丰富度指数与多样性指数,新增Candidatus saccharibacteria和Planctomycetia等微生物类群,促进Herbaspirillum lusitanum、Bacillus sp.、Cellvibrio fibrivorans和Melanocarpus albomyces等功能微生物数量的增加,且菌剂GF-20对玉米种子发芽率无影响。玉米秸秆低温高效降解复合菌系GF-20具有稳定的玉米秸秆分解活性和菌种组成稳定性,能在低温条件(4℃～10℃)下有效加快秸秆分解进程,提高土壤速效养分含量及酶活性,增加土壤微生物群落多样性,具有良好的开发潜力和应用前景。
[Abstract]:Corn straw resources are very rich in China, but its use is not sufficient. Returning straw can increase soil nutrients, to achieve the sustainable development of agricultural production. But in the area of northern China spring maize harvest after low temperature climatic factors such as seasonal restrictions of straw decomposition, stalk rot in soil solution into a long time not only can not be used as fertilizer, when will affect crop after crop sowing quality. In order to speed up the decomposition rate in situ returning maize straw decomposition, improve quality, this study from the low temperature (average temperature of -7 DEG -8 DEG) set for straw returning soil, mining ecological environment in cattle and sheep dung, rotting leaves samples for bacteria the source material, through enrichment culture, carbon source of subculture and the process of cold acclimation, screening of low temperature (4 DEG to 10 DEG) composite microbial system efficient degradation of corn straw, the straw decomposition and clear characteristics, bacteria Composition characteristics, stability and adaptability and application effect, for low temperatures in North China (4 to 10 DEG C) of maize straw fast, high decomposition efficiency and provide a theoretical basis for rational use, and provide strain resources. The main results are as follows: 1. screening of corn straw degrading composite microbial system: low temperature using enrichment culture. Of subculture, low temperature acclimation by generation techniques on the 128 samples collected from corn straw soil, alpine cattle and sheep dung, rotting leaves such as bacteria source materials were selected, 7 low temperature (10 DEG C), temperature (15 DEG C), two type strains and 20 low temperature (10 DEG C) high efficient strains. Further through the analysis of the degradation rate of corn straw and cellulase activity of different strains of dynamic algebra, finally obtain a set at a low temperature (4 DEG to 10 DEG) under High Cellulase Producing Strain GF-, composite and stable degradation of corn straw 20, in the 12h after inoculation into the logarithmic growth phase, cellulase, corn stalk decomposition into simple hydrocarbons or esters. Cultured 15d at 10 DEG C under low temperature conditions, corn straw degradation rate reached 32.29%, compared with a composite microbial system No.8 (the research group in 2013 selected 15 Deg. C degradation rate was 22.02%) 10.27%.2. high efficient low temperature degradation of corn straw composite strains of species composition diversity: a composite microbial system GF-20 consists of 22 kinds of bacteria and 4 fungi. Bacteria were Azonexus hydrophilus, Azospira oryzae, Variovorax boronicumulans, Hydrogenophaga caeni, Herbaspirllum frisingense, Arcobacter cloacae, Pseudomonas fuscovaginae, Cellvibrio Mixtus subsp.mixtus, Seleniivibrio woodruffii, Rhodococcus qingshengii Terribacillus, saccarophilus, Planococcus antarcticus, Bacillus licheniformis, Bacillus tequile NSIS, Clostridium populeti, Clostridium xylanolyticum, Paludibacter propionicigenes, Pedobacter agri, Sphingobacterium cladoniae and Uncultured bacterium. Lotharella globosa Trichosporon is the main fungi, sp., Trichosporon loubieri and Chlamydomonas leiostraca.3. of corn straw degrading composite microbial system of low temperature stability and adaptability: a composite microbial system GF-20 in corn straw decomposition process in central changes is relatively stable, there is the key strain stability; at different temperature (4 DEG -30 DEG) and pH value (6.0-9.0) under the condition of subculture, the temperature (0 DEG -40 DEG) under continuous cultivation, the composite microbial system properties, compositions and functions are stable, has strong stability and adaptability; carbon source for corn straw, nitrogen source when ammonium sulphate composite strains GF-20 strain which is more stable, induced by complex strains producing cellulase, promote the decomposition of substrate Critical dilution; gradient composite microbial system GF-20 was 1014 times higher than that of.4. corn straw degrading composite microbial system in low temperature application: 10% inoculation amount, pH value 6.5, corn straw and ammonium sulfate added than 40:1, 10 degrees Celsius temperature, osmotic concentration of 2% under the conditions of fermentation decomposition agent GF-20 can promote the decomposition of good results at 4 C, 10 C and 30 60d solution rot C conditions, corn straw degradation rate were 29%, 36.75% and 59.47%, 7.21% higher than the control lvkang agents, 9.78% and 10.26%; available nitrogen, available phosphorus, available potassium and organic matter content were increased by 0%-5.32%, 5.26%-14.17%, 2.07%-3.57% and 0.44% ~ 2.94%; significantly increased soil catalase, urease, alkaline phosphatase, invertase, B- glucoside enzyme and cellulase activity increased; soil microbial richness index and diversity index, the new Candidatus saccharibacteria and Planctomycetia. Material group, Herbaspirillum Bacillus sp., promoting lusitanum, fibrivorans and Cellvibrio increase the functional microbes such as albomyces and Melanocarpus, agent GF-20 on maize seed germination rate had no effect. The corn straw degrading composite microbial system GF-20 with low temperature stable corn straw decomposition activity and bacterial composition, in the condition of low temperature (4 DEG to 10 DEG C) under effectively accelerate straw decomposition process, improve the nutrient content and enzyme activity of soil available, increase soil microbial diversity, with good development potential and application prospect.

【学位授予单位】：内蒙古农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S141.4

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