大熊猫粪便微生物多样性分析及纤维素降解产氢菌的筛选鉴定

Microbial diversity analysis of giant panda excrement and separation identification of cellulose degradation hydrogenogens

利用宏基因组测序技术对大熊猫粪便微生物进行了多样性分析,发现大熊猫粪便样品中含有大量可以降解纤维素的厌氧微生物种类,如梭菌科、瘤胃菌科和毛螺菌科等,因此,将熊猫粪便样品作为降解纤维素微生物菌种分离的来源具有可行性。采用刚果红染色法从大熊猫粪便样品中筛选具有降解纤维素产氢能力的菌株,分离获得1株纤维素降解产氢菌株Cel10,根据菌株的形态和生理生化特征并结合分子生物学,鉴定菌株Cel10属于缓纤维梭菌(Clostridium lentocellum),其16S rDNA序列的同源性为98%。菌株Cel10在pH 4.0～8.0、温度25～50℃范围内可以利用纤维素进行生长,其最适pH 7.0,最适生长温度37℃。本文丰富了大熊猫肠道纤维素降解菌的种类,为木质纤维素类农产品加工废弃物的开发和综合利用提供了良好的菌种资源和科学依据。

Microbial diversity analysis of giant panda excrement was carried out using metagenomics sequencing technology. The result showed that a lot of anaerobic microbial species which could degrade and use cellulose were in giant panda excrements, such as Clostridiaceae, Ruminococcaceae and Lachnospiraceae. It was feasible to make giant panda excrement as a source to isolate the microorganism of cellulose degradation. Using CMC-Na as the only carbon source, the strain of cellulose degradation hydrogenogens named Cel10 was screened from giant panda excrement by using Congo red staining method. According to the morphological characteristics and physiological and biochemical characteristics of the strain, the new strain was identified as Clostridium lentocellum by molecular biology, while the homology of its 16 S rDNA sequence was 98%. The strain Cel10 could use cellulose to grow at pH 4.0 ~ 8.0 under 25 ~ 50 ℃. The optimal pH was 7.0 and the optimal growth temperature was 37 ℃. This study not only enriched the cellulose degradation bacteria species of panda guts but also provided good strain resources and scientific basis for development and comprehensive utilization of wastes during the processing of lignocellulosic agricultural products.