培菌白蚁菌圃和粪便微生物多样性分析

Symbiotic microorganism diversity in comb and feces of fungus-growing termite

摘要:

【背景】培菌白蚁是属于白蚁科的一类与鸡枞菌属真菌共生的高等白蚁，其与体内肠道微生物和体外菌圃微生物形成三维共生体系。【目的】分析培菌白蚁菌圃和粪便的微生物多样性，并与肠道微生物进行比较。【方法】通过Illumina MiSeq高通量测序方法对培菌白蚁菌圃和粪便样品进行细菌16S rRNA基因和真菌ITS测序分析。【结果】高通量测序获得培菌白蚁菌圃和粪便样品细菌和真菌的有效序列和OTU数目。5个样品细菌OTU数目在90?199之间，而真菌OTU在10?58之间，细菌的种类多样性明显大于真菌。不论是细菌还是真菌，粪便样品的OTU数目多于菌圃样品。经物种分类分析，菌圃样品主要优势细菌是变形菌门(Proteobacteria)，其相对含量超过82.4%；其次是拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)；粪便样品中优势细菌为拟杆菌门，其次是变形菌门，粪便优势菌属为别样杆菌属和营发酵单胞属，这与培菌白蚁肠道菌多样性组成一致。培菌白蚁菌圃和粪便样品共生真菌主要为担子菌门(Basidiomycota)和子囊菌门(Ascomycota)。菌圃优势真菌为鸡枞菌属(Termitomyces)，相对含量在51.83%以上，菌圃中还鉴定到炭角菌属(1%，Xylaria)。【结论】为今后培菌白蚁-体内外微生物共生关系研究以及微生物的分离培养提供了依据和参考。

Abstract:

[Background] Fungus-growing termites are a kind of higher termites belonging to the family Macrotermitinae that cultivated monofungus (Termitomyces spp.) in their nest. Fungus-growing termites form a three-dimensional symbiosis system with intestinal microbes and microorganisms in the fungus garden. [Objective] To analyze the microbial diversity of fungus combs and termite feces, and compares with intestinal microbes of fungus-growing termites. [Methods] The bacterial 16S rRNA gene mplicon and fungal ITS rRNA analysis were performed by the Illumina MiSeq high-throughput sequencing method. [Results] The number of filtered sequences and OTU numbers of bacteria and fungi in samples of fungus comb and feces were obtained. The number of bacterial OTU in the five samples was between 90?199, while the fungal OTU was between 10?58. The diversity of bacteria was significantly greater than that of fungi. Both the number of OTU in bacteria and fungi in fecal samples are more than that in fungus comb samples. According to the analysis of taxa classification, the dominant phylum in the fungus comb samples are Proteobacteria, with a relative content of over 82.4%; followed by Bacteroidetes and Firmicutes; the dominant bacteria in fecal samples are Bacteroides, followed by Proteobacteria. The dominant bacteria belong to Alistipes and Dysgonomonas, which is consistent with the diversity of intestinal bacteria in fungus-growing termites. The dominant fungi in termite comb and fecal samples are mainly Basidiomycota and Ascomycota. The dominant fungi genus in fungus comb is Termitomyces, with a relative content of more than 51.83%. Xylaria is also identified in the comb. [Conclusion] This study provides a basis and reference for the future research on the symbiosis of fungus-growing termites with in vivo and in vitro microorganisms and the isolation and culture of microorganisms.