骆驼瘤胃内降解含氮杂环化合物细菌的多样性

【目的】作为典型的荒漠动物,骆驼能够采食其他动物不能够食用的具有强烈气味的或有毒的植物,而不影响其正常生理代谢。研究发现骆驼采食的植物毒素与吡啶、喹啉、吲哚等杂环化合物具有相似的化学结构,所以研究骆驼体内是否存在潜在的杂环化合物降解菌具有重要意义。【方法】本研究采集3头骆驼瘤胃内容物,分别以吡啶、喹啉和吲哚3种含氮杂环化合物为唯一碳源和氮源进行5代富集培养。通过高通量测序技术对瘤胃内容物和5代富集培养细菌进行了测序分析。【结果】骆驼肠道中降解杂环化合物(吡啶、喹啉、吲哚)细菌群体样品中变形菌门、放线菌门、拟杆菌门、浮霉菌门和厚壁菌门等5个门类丰富度最高。骆驼瘤胃内降解吡啶的优势菌可能属于鞘氨醇杆菌属和不动杆菌属,降解吲哚的优势菌主要属于芽孢杆菌属,而降解喹啉的优势菌可能以赖氨酸芽孢杆菌属和鞘氨醇杆菌属为主。【结论】骆驼瘤胃原始样品经过吡啶、喹啉、吲哚富集5代后,与原始样品比较优势菌群发生了较大的改变,这说明骆驼瘤胃内蕴含降解吡啶、吲哚和喹啉的细菌,但对吡啶、吲哚和喹啉的降解过程中发挥降解作用的细菌群落存在差异。

Diversity of camel rumen bacteria degrading nitrogen heterocyclic compounds

Objective] As a typical desert animal, camel can eat pungent poisonous plants that are not eaten by other animals, and without affecting their normal physiological metabolism. Many studies found that phytotoxic substances in plants eaten by camel have similar chemical structure to that of pyridine, quinolone, indole and other heterocyclic compounds. However, few studies explored the biodiversity of bacteria degrading potentially heterocyclic compounds in camel rumen. Methods] We used pyridine, quinolone and indole as the only carbon and nitrogen resources, and five generations of enrichment culture method to cultivate camel rumen bacteria, and used high throughput sequencing (Illumina Miseq) to sequence the total DNA of the five generations culture broth. Results] Proteobacteria, Actinobacteria, Bacteroidetes, Planctomycetes and Firmicutes constitute the highest abundance of five categories of camel rumen bacteria degrading heterocyclic compounds. The dominant bacteria of degrading pyridine, quinolone, indole may belong to Sphingobacterium and Acinetobacter, Bacillus, Lysinibacillus and Sphingobacterium. Conclusion] Camel rumen has heterocyclic compounds degrading bacteria.