玉米秸秆低温降解菌剂降解效果的研究

发布时间：2018-05-18 18:26

本文选题：玉米秸秆 + 低温(10℃)　；参考：《内蒙古农业大学》2015年硕士论文

【摘要】：秸秆还田是提高作物秸秆利用效率、提高土壤肥力、改变土壤微环境的有效方式,但由于其自身结构、温度等原因,自然条件下降解速度慢,造成了资源的浪费。本文对已筛选出的降解玉米秸秆的复合菌系的降解效果进行研究,为研究北方低温降解秸秆的生物制剂提供技术支撑。主要研究结果如下：在10℃条件下,对已保存的35个复合菌系,进行复筛、传代的稳定性、秸秆降解效果的测定,选出3个复合菌系,编号为GF-S72、GF-S18、GF-S77。选出的三株在液态条件下对其生长特性和降解效果进行测定：在10℃条件下,三株复合菌系的生长曲线在接菌后直接进入对数期：pH值在培养初期迅速下降,随后稳定在7.2左右；FPA、C1、Cx、Cb酶活在添加菌液后均先升高,培养后期下降,GF-S72最高酶活分别为0.82、1.41、1.33、1.25IU, GF-S18最高酶活分别为0.82、1.31、1.35、1.35IU; GF-S77最高酶活分别为0.80、1.23、1.26、1.32IU; GF-S72、 GF-S18、GF-S77培养15d降解率分别为25.60%、21.20%、21.41%,显著高于CK；GF-S72、GF-S18、GF-77、CK纤维素残余量分别从培养前的0.45g降解到0.32、0.32、0.33、0.39g；半纤维素残余量分别从0.27g降解到0.17、0.19、0.18、0.20g；木质素残余量分别从0.09g降解到0.06、0.05、0.06、0.08g,其中纤维素、木质素残余量显著高于CK。探讨其中两组玉米秸秆低温降解复合菌系GF-S72、GF-S18、GF-S77接种于土壤模拟还田秸秆的促腐效果。结果表明：在10℃条件下,施加复合剂GF-S72、GF-S18、GF-S77提高玉米秸秆的降解效果。45d降解率分别为51.50%、37.59%、34.74%,显著高于CK1; 45d GF-S72、GF-S18、GF-S77纤维素残余量分别从培养前的2.44g降解到1.12、1.35、1.30g,半纤维素残余量分别从1.32g降解到0.72、0.87、0.82g,木质素残余量分别从0.42g降解到0.27g、0.31g、0.29g,显著高于CKl。腐殖质碳组成、土壤酶活均高于未添加复合菌系的土壤。因此,复合菌系GF-S72和GF-S18是具有开发潜力的复合菌系。利用PCR-DGGE技术研究土微生物多样性,结果表明,施加秸秆复合菌剂的土壤DNA丰富度和Shannon指数高于CK0(原始土壤)、CK1(不加菌)。通过切胶回收条带、连接转化及测序分析后,主要包括变形菌门(Proteobacteria),厚壁菌门(Firmicutes)、拟杆菌门(Bacteroldetes)。
[Abstract]:Straw returning is an effective way to improve the utilization efficiency of crop straw, improve soil fertility and change the soil microenvironment. However, due to its own structure, temperature and other reasons, the degradation rate is slow under natural conditions, resulting in the waste of resources. This paper studies the degradation effect of the compound bacteria system which has been screened out in order to study the north. The biological agents of low temperature degradation of straw provide technical support. The main results are as follows: under the condition of 10 centigrade, the 35 composite strains were rescreened, the stability of the generation and the degradation effect of straw were determined, and 3 compound strains were selected, and the three strains selected by GF-S72, GF-S18 and GF-S77. were grown under the liquid condition. The degradation effect was determined: at 10 C, the growth curve of three strains of composite strains entered the logarithmic phase directly after inoculation: the pH value declined rapidly in the early stage of culture and then stabilized at about 7.2; FPA, C1, Cx, Cb enzyme increased first, and decreased in the later culture, and the highest GF-S72 activity was 0.82,1.41,1.33,1.25IU, GF-S18, respectively. The highest enzyme activity was 0.82,1.31,1.35,1.35IU, the highest enzyme activity of GF-S77 was 0.80,1.23,1.26,1.32IU, and the degradation rates of 15d in GF-S72, GF-S18 and GF-S77 were 25.60%, 21.20%, 21.41%, respectively, higher than CK, GF-S72, GF-S18, GF-77. The residues of lignin were degraded from 0.27g to 0.17,0.19,0.18,0.20g, respectively, and the residual lignin residues were degraded from 0.09g to 0.06,0.05,0.06,0.08g, respectively. The residue of cellulose and lignin was significantly higher than that of CK., among which two groups of corn straw low temperature degradation compound bacteria GF-S72, GF-S18, GF-S77 were inoculated in soil simulated returning straw. The results showed that: in 1 Under 0 centigrade, GF-S72, GF-S18, GF-S77 were applied to improve the degradation of corn straw, and the degradation efficiency of corn straw was improved by 51.50%, 37.59%, 34.74%, significantly higher than CK1; 45d GF-S72, GF-S18, and GF-S77 cellulose residue were degraded from 2.44g to 1.12,1.35,1.30g, and the residue of hemicellulose was degraded from 1.32g to wood, respectively. The residual mass of the particles was degraded from 0.42g to 0.27g, 0.31g, and 0.29g, which was significantly higher than that of the CKl. humus. The soil enzyme activity was higher than that of the soil that did not add compound bacteria. Therefore, the composite strain GF-S72 and GF-S18 were the complex strains with potential for development. The microbial diversity of soil was studied by PCR-DGGE technology. The results showed that the compound microbial agent was applied to the soil. The DNA richness and Shannon index of soil were higher than that of CK0 (original soil), CK1 (non bacteria). After reclaiming the strip by cutting the glue, the connection transformation and sequencing analysis mainly included the deformable bacteria gate (Proteobacteria), the thick wall fungus gate (Firmicutes), and the bacteriobacteria (Bacteroldetes).
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S141.4

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