耐高温木质纤维素降解菌株的分离筛选、鉴定及降解工艺的研究

Lignocellulose Degradation Strains with High-temperature Resistance:Isolation, Screening, Identification and Degradation Process

本研究旨在筛选出在高温条件下具有较强木质纤维素降解酶活性的细菌菌株,探究其降解秸秆木质纤维素的特性。从太白山林区温泉采集土壤样品并在高温条件下进行富集培养,利用脱色圈试验和比色法筛选出目标菌株,通过形态观察和16S rDNA序列分析鉴定菌株种类。对高温富集初筛所得菌株的纤维素酶、漆酶、木质素过氧化物酶和锰过氧化物酶活性进行测定。菌株X-08的纤维素酶活为0.02872 U/mL,菌株M-17的MnP、LiP和Lac酶活分别为51 U/mL、672 U/mL和192 U/mL。鉴定出菌株X-08为Anoxybacillus rupiensis,M-17为Geobacillus thermocatenulatus。采用双菌降解玉米秸秆,20天后木质素和纤维素的降解率分别达到24.51%和20.47%。研究结果为农业废弃物生物降解提供了新的细菌菌种资源,并为秸秆中木质纤维素的降解处理方法提供了新的思路。

This study aims at screening out the bacterial strains with higher lignocellulolytic degradation enzyme activity under high temperature, and to explore the characteristics of straw lignocellulose degradation by bacterial strain. Soil samples were collected around forest hot spring in Mount Taibai and were used for enrichment culture at high temperature. The target strains were selected by decolorization circle method and colorimetric method. The types of strains were identified by morphological observation and 16 S rDNA sequence analysis. The activities of cellulase, laccase, lignin peroxidase and manganese peroxidase were determined.The results showed that the cellulase activity of X-08 strain was 0.02872 U/mL, and the activity of MnP, LiP and Lac in M-17 strain was 51 U/mL, 672 U/mL and 192 U/mL, respectively. The X-08 strain was identified as Anoxybacillus rupiensis and M-17 strain was Geobacillus thermocatenulatus. With double bacteria degradation, the degradation rate of lignin and cellulose was 24.51% and 20.47% respectively after 20 days.The results could provide new bacterial resources for the biodegradation of agricultural waste, and a new idea for the degradation of lignocellulose in straw.