Diversity Of Intestinal Microbiota Of Healthy Pastoral Livestock In Inner Mongolia Xilin Gol

Intestinal microorganism were isolated and identified using pure culture method and16S rRNA gene sequencing from feces samples of36healthy pastoral livestock, including cattle, horses, goats and sheep, which were collected from Inner Mongolia Xilin Gol. Meanwhile, denaturing gel gradient electrophoresis (DGGE) and real-time quantity PCR (qPCR) were applied to analyze the diversity and population of intestinal flora. The conclusions of this study would like to lay a foundation for the exploitation and screening of probiotics for pastoral livestock. Several main results were obtained as follows:Intestinal bacteria were isolated by modified MRS agar, and179pure isolates were acquired by means of morphological method. According to the16S rRNA gene sequences, all the isolates were classified into32species, which belonged to14genera, including Lactobacillus, Propionibacterium, Streptococcus, Escherichia, Staphyloccus, Bacteroides, Actinomycetes, Blautia, Clostridium, Enterococcus, Bifidobacterium, Enterobacter, Kluyvera and Ruminococcus. As far as biodiversity was concerned, the isolates in the feces of cattle were mainly Firmicutes (61.4%), Proteobacteria (25.0%) and Actinobacteria (11.4%); for the horses, the isolates were mainly Firmicutes (87.2%) and Bacteroidetes (10.3%); for goats and sheep, the main isolates were Firmicutes (61.5%) and Actinobacteria (32.3%).The diversity of intestinal micobiota and Lactobacillus were evaluated using PCR-DGGE. The results showed that the constitution of intestinal flroa and Lactobacillus of different livestock is different, and some certain differences existed in the inter-group. The biodiversity of total intestinal bacteria in cattle is higher, followed by sheep and goats, while it was poor in horses. Species which were discrepant in all the samples were mainly Bacillus megaterium, Aeromonas veronii, Veillonella parvula, Staphylococcus schleiferi, Pseudomonas tolaasii and so on. Besides, compared to the horses and goats, the biodiversity of intestinal Lactobacillus is higher in sheep, and poorer in cattle. The main different Lactobacillus among samples were L. acidophilus, L. kitasatonis, L. pontis, L. taiwanensis, L. equi and L. fermentum or L.vaginalis.qPCR was performed to detect the population of dominant bacterium group. The results revealed that for Lactobacillus and Clostridum coccoides, compared to cattle, there was a significantly higher number in the intestinal of goats, sheep and horses, while no distinct difference existed among them. For Desulfovibrio, the population was balanced among all the samples. For Megasphaera, the population in sheep’s gut was remarkably more than that in cattle and horses, and there was no significant difference between goat and other three groups. For Bifidobacterium and Ruminococcus, the population in goats was markedly larger than that in cattle and horses, but sheep was indifferent. For Treponema, the population in horses was greater than other samples. Specially, comparing the population of above mentioned7genera in each group, the number of both Lactobacillus and Bifidobacterium was lower than the other5genera.