摘要
为给冷凉地区秸秆还田提供菌株资源,以常年处于低温环境的土壤与富含纤维素的腐烂物为菌源,以富集、继代培养方法筛选秸秆降解菌系和生产中主推的秸秆腐熟剂为试材,在15℃和20℃,pH 4.5、5.5、6.5、7.5、8.5、9.5条件下发酵秸秆,每隔24 h测定发酵液OD_(600)值,发酵15天测定滤纸酶、纤维素酶活性和秸秆降解率,探讨其对玉米秸秆的降解效果。结果表明,继代培养5~6代菌系分解纤维素的速度加快;15℃2种试材不同pH发酵液OD_(600)值第6天达到峰值,最高峰值均在pH 7.5;20℃2种试材不同pH发酵液OD_(600)值第7天达到峰值,秸秆降解菌系8号最高峰值为pH 8.5,秸秆腐熟剂最高峰值为pH 5.5。15℃pH 8.5秸秆降解菌系8号滤纸酶活性显著高于秸秆腐熟剂;pH 7.5秸秆降解菌系8号纤维素酶活性显著高于秸秆腐熟剂;而秸秆腐熟剂纤维素酶活性在20℃pH 4.5时高于秸秆降解菌系8号。15℃和20℃条件下,秸秆降解菌系8号pH 7.5秸秆降解率高,而秸秆腐熟剂为pH 4.5和pH 5.5秸秆降解率高;相同发酵条件下,秸秆降解菌系8号秸秆降解率显著高于秸秆腐熟剂。秸秆降解菌系8号降解秸秆适宜条件为中低温中性偏碱性,而秸秆腐熟剂为中温偏酸性。
The paper aims to provide bacterial strain resources for straw returning to field in cold and cool areas.Taking the soil in low temperature environment and cellulose-rich decomposing materials as the bacterial source,the straw-degrading bacterial strains were screened by enrichment and subculture,and the straw decomposing agent,which is the main recommendation in production,was used as the test material.Fermentation of straw was conducted at 15℃and 20℃,and under pH 4.5,5.5,6.5,7.5,8.5,9.5,the OD_(600) value of the fermentation broth was measured every 24 hours,and the filter paper enzyme activity,cellulase and straw degradation rate were measured after 15 days of fermentation,to explore the degradation effect of corn straw.The results showed that the rate of cellulose decomposition was accelerated when the strain was subcultured for 5-6 generations;the fermentation broth of the two test materials with different pH reached the peak on the 6th day at 15℃,and the highest peak was at pH 7.5.The two test materials were different at 20℃.The OD_(600) value of pH fermentation broth reached the peak value on the 7th day,the highest peak value of straw-degrading bacterial strains No.8 was pH 8.5,and the highest peak value of straw decomposing agent was pH 5.5.The filter paper enzyme activity of straw-degrading bacterial strains No.8 at pH 8.5 and 15℃was significantly higher than that of straw decomposing agent,so did the cellulose activity at pH 7.5.The cellulase activity of straw decomposing agent was higher than that of straw-degrading bacterial strains No.8 at pH 4.5 and 20℃.Under the conditions of 15℃and 20℃,straw-degrading bacterial strains No.8 had higher straw degradation rate at pH 7.5,while the straw decomposing agent had higher degradation rate at pH 4.5 and pH 5.5.Under the same fermentation conditions,straw-degrading bacterial strains No.8 had significantly higher degradation rate of straw than straw decomposing agent.The suitable conditions for straw-degrading bacterial strains No.8 to degrade straw are neutral and alkaline under medium and low temperature,while the conditions for the straw decomposing agent are acidic under medium temperature.
作者
张云
萨如拉
包桂荣
萨茹拉其其格
邰继承
李响
ZHANG Yun;SA Rula;BAO Guirong;SA Rulaqiqige;TAI Jicheng;LI Xiang(College of Agriculture,Inner Mongolia Minzu University,Tongliao,Inner Mongolia 028000;Ordos City Forestry and Grassland Comprehensive Law Enforcement Detachment,Ordos,Inner Mongolia 017000)
出处
《中国农学通报》
2022年第28期21-27,共7页
Chinese Agricultural Science Bulletin
基金
国家自然基金项目“低温秸秆降解复合菌系作用机制与途径研究”(31960383)
内蒙古自治区自然科学基金项目(2018LH03007)。
关键词
秸秆降解菌系
PH
温度
秸秆降解率
酶活性
straw-degrading bacterial strains
pH
temperature
straw degradation rate
enzymatic activity
