玉米秸秆低温高效降解复合菌系发酵条件优化及其制剂的初步研究

发布时间：2018-04-30 05:37

  本文选题：玉米秸秆 + 低温(10℃)　； 参考：《内蒙古农业大学》2016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、改善土壤微环境的有效方法,但由于北方地区秋收后玉米秸秆原位还田因低温而腐熟太慢,对耕整地、播种质量等产生不利影响而不能普及应用,大量秸秆运出农田或焚烧,造成了秸秆资源的浪费和环境污染。因此本研究选用课题组从自然界锯末中分离出的高效降解玉米秸秆复合菌系对GF-S3、GF-S72,研究其产酶特性,优化发酵条件及液态发酵条件下对秸秆的降解能力,并制成生物菌剂,应用于大田。为解决北方低温条件下玉米秸秆田间降解难的问题提供理论基础和技术支撑。主要研究结果如下：1.对GF-S3、GF-S72复合菌系测定生长曲线、pH值、纤维素酶活性、秸秆降解率、木质纤维素组成,GF-S3、GF-S72复合菌系15d的玉米秸秆降解率分别为23.50%、25.50%。纤维素、半纤维素、木质素残余量分别从培养前的2.60g、1.38g、0.42g；2.56g、1.37g、0.42g降解到1.27g、1.17g；0.70g、0.65g;0.24g、0.23g。2.通过测定纤维素酶活性及玉米秸秆降解率并且进行正交试验,研究了玉米秸秆低温高效降解复合菌系的发酵条件,复合菌系GF-S72的最佳摇瓶培养条件为：接种量2%、初始pH=8、培养温度10℃、培养时间6d、装液量18mL、以尿素为氮源、氮源浓度为0.1%、混合氮源比2：1、碳氮比20：1。3.研究玉米秸秆低温高效降解菌系的制剂配方。结果发现最佳载体为硅藻土,菌液：载体=3：1、菌剂与秸秆配比为0.05 g/2 g,GF-S72复合菌剂pH值为8.2；含水量为1.42%；纤维素酶活性为0.879 U·mL-1；OD为0.302;保藏湿度为10%,保藏温度为15℃,此条件下保藏期目前可达3个月。4.结合玉米秸秆的降解率及多种酶活性指标,来验证玉米秸秆降解复合菌剂性能。GF-S72对玉米秸秆的降解率：在室内土培条件下为15℃10℃;在室外土培条件下为GF-S72LKCK;在大田试验条件下为LKGF-S72CK。GF-S72处理后的土壤酶活性：在室内土培条件下,14d时10℃、15℃的纤维素酶活性分别为1.14 mg/g、1.42mg/g；28d时10℃磷酸酶、脲酶分别为51.73 mg/g、3.42mg/g；15℃磷酸酶、脲酶分别为58.23 mg/g、4.10mg/g。在室外土培条件下,14d时GF-S72、LK的纤维素酶活性分别为1.30 mg/g、1.20mg/g；28d时GF-S72的磷酸酶、脲酶分别为47.29 mg/g、3.40mg/g,LK的磷酸酶、脲酶分别为45.05 mg/g、3.22mg/g。在大田试验条件下,14d时GF-S72、LK的纤维素酶活性分别为1.28 mg/g、1.42mg/g；28d时GF-S72的磷酸酶、脲酶分别为51.90 mg/g、3.49mg/g,LK的磷酸酶、脲酶最高分别为57.30mg/g、3.59mg/g。
[Abstract]:Straw returning is an effective method to improve the utilization efficiency of crop straw, improve soil fertility and improve soil microenvironment. Sowing quality and other adverse effects can not be popularized and a large amount of straw is transported out of farmland or burned resulting in waste of straw resources and environmental pollution. Therefore, in this study, we selected the high efficient biodegradable corn straw compound strain from natural sawdust to study the enzyme production, the optimum fermentation conditions and the degradation ability of the straw under the liquid fermentation conditions, and to make the biological bacteriological agent, and to study the enzyme production characteristics of GF-S3N GF-S72, and to optimize the degradation ability of the straw under the conditions of fermentation and liquid fermentation. Applied to the field. It provides theoretical basis and technical support for solving the problem of field degradation of corn straw under low temperature conditions in northern China. The main results are as follows: 1. The growth curve pH value, cellulase activity, straw degradation rate and lignocellulose composition of GF-S3GF-S72 composite strain were measured for 15 days. The degradation rates of corn straw were 23.50% and 25.50%, respectively. The residual amounts of cellulose, hemicellulose and lignin were degraded from 2.60 g / L 1.38 g / L 0.42 g / L ~ 2.56 g / L ~ (1.37) g ~ (-1) ~ 0.42 g to 1.27 g ~ (-1) ~ (17) g ~ (-1) ~ 0.70 g ~ (-1) N ~ (0.24) g ~ (-1) ~ 0.24 g ~ (2) ~ (2) respectively. By measuring cellulase activity and the degradation rate of corn straw, the fermentation conditions of low temperature and high efficiency degradation of composite bacteria by corn straw were studied. The optimum culture conditions of GF-S72 were as follows: inoculation amount 2: 1, initial pH = 8, culture temperature 10 鈩，

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