Characterization Of The Bacterial Diversity In Faeces From Captive Giant Panda During Diet Conversion Period

Diet conversion period is a special stage for giant panda. In captive conditions, the subadult panda’s that was ten months old enter the diet conversion period. During this period, giant panda need adapt to highly fibrous bamboo as their main food from high-protein diet and form a special digestion system to digest cellulose and hemicellulose. Other studies proved that diet alterations affect intestinal microbiota composition and host resistance. Intestinal microbiotas play a key role for giant panda to digest highly fibrous bamboo.In order to explore the diversity of intestinal bacterium of giant panda during diet conversion period, ERIC-PCR was used to choose samples with higher diversity, and constructed 16S rDNA clone library of intestinal flora of giant panda, Hint I and Msp I were Used to cluster analysis and sequencing analysis. The contents are summarized as follows:1. The intestinal flora’s DNA was extracted from three giant panda in diet conversion period, subsequently used as templates with ERIC-PCR to generate community fingerprint. Choosing higher diversity samples (F6, F7, G8, J9, G10, J11, J12) by similarity and diversity of fingerprint.2. The diversity of intestinal bacteria of giant panda in diet conversion period was analyzed by 16S rDNA cloning library and RFLP.787 positive sequences were obtained, and they were classified into 224 opertional taxonomic units (OTUs). In diet conversion period, the coverage of clone library was more than 78.5% (from 78.6% to 86.2%), which indicate that we have detected the majority of the present microbioma in diet conversion period. The all diversity index of Shannon index (H’), Simpson index (1/D) and SChaol (S) indicated that the diversity of intestinal flora of giant panda of diet conversion was very rich, and the diversity of intestinal bacterium in earlier and later of diet conversion period was higher than the middle of diet conversion period.3.16S rDNA sequence analysis revealed that intestinal floras inhibited in giant panda gut were affiliated with the phyla Firmacutes, Proteobacteria, Bacteroidetes, Fusobacteria and uncultured bacterium. The phyla Firmacutes and Proteobacteria were the predominant bacteria in the all of giant panda’s diet conversion. In the diet conversion of giant panda,482 clones (61.25% of total clones) were included in the phylum Proteobacteria, clustering within three subdivisions (α-, γ-or ε-Proteobacteria). The 482 clones were affiliated to 17 groups. and 241 clones (30.62% of total clones) were distributed within 10 genuses. Their proportion was changed during the period of diet conversion. In the phyla Firmacutes, the predominant bacteria were Clostridium and Coccus, while in the phyla Proteobacteria, the predominant bacteria were Escherichia and Acetobacter.