棉秆纤维素降解复合菌系的筛选及其分解特性研究

[目的]从自然环境中筛选降解棉秆的纤维素分解复合菌系,以降解棉秆中的纤维素.[方法]采用PCS培养基,从牛粪、土壤、羊的瘤胃液和发酵粪中筛选纤维素分解复合菌系,通过连续继代培养,获得相对稳定的复合菌系,再获得粗酶液,测定三种酶活(CMC、FPA、纤维二糖酶)和酶解效果.[结果]牛粪的降解纤维素复合系,酶活分别为CMC 11.95 U/mL、FPA 8.29 U/mL、纤维二糖酶11.03 U/mL,产酶动态变化在4～5d酶活性比较高,确定发酵周期为5d,pH值先上升后下降,在发酵的4～5d,pH值相对较高,以后开始下降,维持稳定,呈现弱碱性.[结论]来自牛粪的纤维素降解菌降解能力最强,降解棉花秸秆效果较好,棉秆失重率为18;,糖化率为19.39;.

Screening of Microbial Community with Capacity of Degrading Cellulose Effectively and Its Characteristics

【Objective】A group of cellulose degrading microbial flora was screened from natural environments.【Method】The cellulose degrading microbial flora was screened from decomposed cellulose bacteria from cow dung,soil,rumen of sheep and fermentation manure by PCS nutrient medium and continuous culture.Stability compound bacteria were screened from ox dung.【Result】The flora showed a stable and strong capability of degrading cellulose.CMC was respectively 11.95 U/mL and FPA 8.29 U/mL.-glycosidase enzyme was 11.03 U/mL.Enzyme production dynamic change in 4-5 d of the enzyme activity was higher,and sure fermentation period was 5 d,pH value after rising first dropped in fermentation of 4-5 d,and pH value was relatively higher,and started to decline later,maintaining a stable but weak alkaline.【Conclusion】The cellulose degrading microbial flora from cow dung has the strongest degradation ability in cotton stalk.