烟梗纤维素降解菌株HF-09的分离鉴定和降解特性

Isolation,identification and degradation characteristics of tobacco stem lignocellulose-degrading bacteria HF-09

为了降低烟梗中的木质纤维素含量,解决其工业利用价值低的问题,筛选具有降解烟梗木质纤维素应用潜力的细菌,利用纤维素酶筛选培养基,从昆明市的烟草栽培土壤中分离得到1株烟草木质纤维素降解菌株HF-09。经形态学观察和生理生化分析,结合16S rRNA测序和系统进化分析将该菌株鉴定为贝莱斯芽孢杆菌(Bacillus velezensis)。该菌在pH 5~9的范围内或75℃以下存活率均达90%以上,在培养8~20 h生长达到对数生长期,具有很强的适应性。经过对烟梗(红大C3F)进行10 d的降解处理,发现纤维素降解率为20.82%、半纤维素降解率为30.28%、木质素降解率为19.34%。同时,电镜扫描显示,该菌具有显著的破坏烟梗组织结构的能力。

In order to reduce the content of lignocellulose in tobacco stems and solve the problem of low industrial use value,bacteria with potential for degradation of tobacco stem lignocellulose were screened.A cellulase screening medium was used to isolate a tobacco lignocellulose-degrading strain HF-09 from tobacco cultivation soil in Kunming city.After morphological observation and physiological and biochemical analysis,combined with 16S rRNA sequencing and phylogenetic analysis,the strain was identified as Bacillus velezensis.The survival rate of the bacterium was above 90%in the range of pH 5~9 or below 75℃,and it reached the logarithmic growth phase in 8~20 h,which had strong adaptability.After 10-day degradation of tobacco stems of Hongda(C3F),the cellulose degradation rate was 20.82%,the hemicellulose degradation rate was 30.28%,and the lignin degradation rate was 19.34%.At the same time,scanning electron microscopy showed that the bacteria had a significant ability to damage the structure of tobacco stems.