高活性秸秆降解菌群的构建及产酶条件优化

纤维素的开发与利用在当今资源紧缺的社会下是当务之急,秸秆含有大量的纤维素,木质素.它从一个农业废弃物逐渐变为了再生资源开发的焦点.为了将秸秆资源充分利用起来,我们以牛粪,羊粪及含腐烂树叶土壤的混合物为材料,利用限制性培养技术,对其中能够降解纤维素的微生物进行驯化培养,并得到一组高效降解纤维素的菌群.利用CMC糖化力法和滤纸酶法测定该菌群的纤维素降解能力.对菌群进行菌种的分离,并进行生理生化试验分析各个菌株的特性.通过正交试验对该菌群的最佳产酶条件进行优化.得到的菌群CMCase酶活的高达80U/mL,滤纸酶活高达152U/mL.得到的最佳产酶条件为蛋白胨纤维素培养基以滤纸为碳源,pH 5.0条件下35℃静置培养.筛选性能稳定的高产秸秆降解菌群,为充分利用秸秆等农业废弃物提供了新的方向.

Construction of Straw Degradation Bacteria Group and Conditions Optimization of Their Highly Active Enzyme

The exploitation and use of cellulose should be placed before everything in this society with resource scarcity.Straw contains a lot of cellulose and lignin.It gradually becomes the focus of the renewable resources development from an agricultural waste.In order to make full use of straw resources,a mixture of cow muck,sheep droppings and soil which contains decayed leaves for material was used to set a flora with high cellulose degradation ability by limit culture method.Besides,the ability of this group of high efficiency degradation bacterium was decised by determining its activity of CMCase and filter paper activity.Then each strains of bacteria in this group was separated.What's more,physiology and biochemistry of each bacteria were analysed.The best enzyme production conditions the flora is optimized through orthogonal test.A flora with CMCase activity living up to 80 U/mL and filter paper activity is as high as 152 U/mL was achieved.The best enzyme production conditions which is using the PCS culture medium with filter paper cellulose culture medium for carbon sources,pH 5.0,35 ℃ for stationary culture was achieved.It will become a new direction to screen high stable yield bacteria group for straw degradation.