低温秸秆降解菌的酶活、降解效果及对土壤养分、酶活的影响

发布时间：2018-03-04 08:21

本文选题：低温秸秆降解菌　切入点：秸秆还田　出处：《吉林农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：秸秆还田是一项提高秸秆利用率,提高土壤肥力的有效措施,也是秸秆资源化利用的主要方式。但是在北方由于温度等原因影响,秸秆进入土壤之后,腐解较慢,达不到预期的效果。为了使秸秆在低温或常温条件下快速腐解,起到培肥土壤,又不影响下季耕种的作用,在秸秆还田的同时施用低温高效快速分解秸秆的菌剂是非常必要。低温秸秆降解菌剂的施用对土壤养分有一定的影响。因此,弄清低温秸秆降解菌剂的施用对土壤养分、土壤酶活力的影响,具有重要的理论和实践意义。本文通过模拟秸秆还田的盆钵培养试验与室内分析相结合的方法,研究了低温秸秆降解菌的酶活特性、秸秆还田下低温秸秆降解菌对秸秆降解效果以及土壤养分、土壤酶活力的影响,为弄清低温秸秆降解菌的在低温条件下降解秸秆的机理,为秸秆菌剂在田间应用提供理论依据。研究结果表明,本试验所选择的A14和A41两株菌剂,在12℃的条件下培养8d时,菌剂的酶活力达到了最大值,其中A14的纤维素酶活力为28.95U/ml,而A14和A41的混合菌株,纤维素酶活力达到了36.54U/ml。各个菌剂的纤维素酶活力、淀粉酶活力、果胶酶活力以及木质素酶活力均在培养8d时出现了峰值,因此说明了在培养8d时,菌剂的酶活力最强。混合菌剂的酶活力较高,因此在降解过程中,降解速度也较其他菌剂快。培养8d后,同一种菌株各种酶的活力不同。其中,菌株A14表现为:菌株A14表现为:纤维素酶果胶酶淀粉酶木质素酶;A41表现为纤维素酶淀粉酶果胶酶木质素酶;与A14表现出同样的规律,混合菌表现为:纤维素酶果胶酶素酶淀粉酶木质素酶,且混合菌剂的酶活力均高于单一菌株的酶活力;这说明,两种菌剂混合会促进酶活力的增加;在低温的条件下,能产生较多的纤维素酶活力的菌株对秸秆的降解效果较好,同时具有较高的淀粉酶和果胶酶对秸秆的降解也是有益的。在模拟秸秆还田的盆栽培养实验中,在培养20d后,菌株A14、A41及混合菌株对玉米秸秆的纤维素降解率达到了35.10%、34.12%和38.90%,均比无菌对照高13.67%~18.45%。施用菌剂的玉米秸秆的纤维素、半纤维素和木质素的降解率也明显高于无菌对照。同时结合电镜扫描的结果显示,菌株对秸秆的降解从内部开始进行,然后使整个秸秆组织结构开始呈现松散状态,施用混合菌剂处理的玉米秸秆对结构的破坏程度较高。秸秆还田下施用秸秆降解菌剂对提高土壤养分含量及土壤有机质的含量有促进作用,不同处理均明显高于未施加菌剂的处理。施加菌剂对土壤有机质含量可增加11.64%~27.46%,比空白对照高出29.33%~44.12%,施用秸秆降解菌剂使土壤速效氮、磷、钾均有不同程度的增加,其中土壤速效磷含量增加可达12.46%~42.2%,尤其是施加混合菌剂的增加程度最为明显。同时施用菌剂对土壤酶活力的提高也有明显作用,其中土壤脲酶的增加最为明显,可达55.88%~68.21%,而施加混合菌剂对土壤脲酶含量的增加最大,较未施加菌剂的高61.42%。对土壤转化酶、土壤磷酸酶以及土壤过氧化氢酶,均有不同程度的增加。
[Abstract]:Straw is an improved straw utilization, effective measures to improve soil fertility, it is also a main way of straw resources utilization. But in the North due to temperature and other factors, after the straw into the soil, decaying slowly, reach the expected effect. In order to make the straw in the fast rot low temperature solution. To fertilize the soil, and not under the influence of season cultivation, while straw application of low temperature and high efficiency rapid decomposition of straw inoculants is very necessary. The application of low temperature straw degrading bacteria have certain effects on soil nutrients. Therefore, low temperature straw degrading bacteria to fertilization on soil nutrient, soil enzyme activity and it has important theoretical and practical significance. The pot simulation of straw cultivation analysis combined with laboratory test, studied the low temperature straw degrading enzyme activity of straw. Returning straw degrading bacteria under low temperature on the degradation of straw and soil nutrients, soil enzyme activity, to clarify the mechanism of low temperature straw degrading bacteria under the condition of low temperature degradation of straw, to provide a theoretical basis for straw inoculants in field application. The results show that the choice of the A14 and A41 of two strains of bacteria cultivation, 8D at the temperature of 12 DEG C, microbial enzyme activity reached the maximum value, the cellulase activity of A14 was 28.95U/ml, A14 and A41 mixed strains, cellulase activity reached 36.54U/ml. cellulase activity, amylase activity were each inoculum, pectinase activity and lignin enzyme activity peak appeared in 8D culture, therefore the 8D in culture, the strongest activity agent. High enzyme activity of mixed agents, so in the process of degradation, the degradation rate was also lower than that of other agents. After 8D, the same kind of bacteria All kinds of enzyme activity in different strains. Among them, strain A14 showed: strain A14 showed: cellulase amylase pectinase lignin enzyme; A41 showed cellulase amylase pectinase enzyme lignin; and A14 showed the same regularity, mixed bacteria showed: cellulase enzyme amylase enzyme lignin pectin enzyme, enzyme activity and enzyme activity mixed agents were higher than that of single strain; this shows that the two increase will promote the activity of mixed bacteria; in low temperature condition, the better degradation effect of cellulase produced more strains on the straw degradation, but also has high amylase and pectinase on straw is useful. In the simulation of straw pot culture experiment, in cultured 20d, strain A14, A41 and mixed strains of corn straw cellulose degradation rate reached 35.10%, 34.12% and 38.90% were 13.67%~18 higher than aseptic The application of.45%. agent of corn straw cellulose, hemicellulose and lignin degradation rate is significantly higher than the control. At the same time combined with aseptic scanning electron microscopy showed that the degradation of straw was started from the inside, then the whole organization structure has a loose straw state, maize straw mixed agents applied to structural damage a higher degree. Under the application of straw straw degrading bacteria have effect on improving the content of soil nutrient content and soil organic matter, different treatments were significantly higher than the treatment without inoculum. Imposetheagents on soil organic matter content increased 11.64%~27.46%, 29.33%~44.12% higher than the blank control, the application of straw degrading bacteria to soil available nitrogen, phosphorus K, increased, the content of soil available phosphorus increased up to 12.46%~42.2%, especially applying mixed agents increase process Is the most obvious. At the same time improve the application of microbial inoculum on soil enzyme activity also has obvious effect, which increased soil urease was the most, up to 55.88%~68.21%, while applying mixed agents on soil urease content increase, high 61.42%. is applied to agents on soil invertase, phosphatase and catalase, there were different the degree of increase.

【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X712;X172

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