玉米秸秆降解菌群CDS-10筛选及其特性研究

Study on the selection and characteristics of CDS-10 for degradation of corn straw

为筛选出对玉米秸秆等农业固体废弃物能够快速降解的微生物菌群,从不同畜禽粪便和秸秆腐熟物中分离出5类初始菌群并相互组配,通过继代培养筛选出高效稳定的降解菌群CDS-10,测定其不同培养代数的降解能力,酶活性和降解成分变化。结果表明:随着培养代数的增加,CDS-10菌群的降解能力逐步增加并在第30代后趋于稳定,分解率为63.09%;外切葡聚糖酶,内切葡聚糖酶,滤纸酶活性在第30代后趋于稳定,其中,外切葡聚糖酶活性显著升高,达到11.63 U/mL;玉米秸秆中纤维素,半纤维素和木质素均有不同程度减少,半纤维素的降解率最高,达92%。说明在适宜条件下,CDS-10菌群对玉米秸秆具有稳定高效的分解能力,主要降解玉米秸秆成分中的半纤维素,且影响降解效果的酶主要是外切葡聚糖酶。

In order to screen out the microflora for rapidly decomposing the agricultural solid wastes such as maize straw,5 types of initial bacterial flora separated from livestock manure and fermented straw were used to collocate with each other for finding out the highly efficient and stable microflora.In which,CDS-10 was screened out by subculture and its degradation ability and enzymatic vigour were tested.The results showed that along with the increment of culture algebra the degradation ability of CDS-10 was gradually increasing and stabilizing,and decomposition rate was 63.09%when it reproduce to the 30 th generation;The enzymic vigour of exoglucanase,endoglucanase and filter paper enzyme tended to be stable since the 30 th generation.The exoglucanase vigour significantly increased to 11.63 U/mL;the content of the cellulose,hemicellulose and lignin in maize straw was decreased to certain degrees,among them,the degradation rate of hemicellulose was the highest(92%).This suggested that CDS-10 performed a stable and efficient ability to decompose ingredient of maize straw especially hemicellulose under the favorable conditions,and exoglucanase was the main enzyme to influence the degradation effect.CDS-10 showed a promising future in terms of straw resource utilization.