Comparison of Bacterial and Fungal Community Structure and Potential Function Analysis of Yak Feces before and after Weaning

Abstract

Weaning is one of the most stressful periods in yak growth. However, the impact of weaning on microbial diversity, structure, and potential function of yak feces is not clear. In this study, 12 Xinjiang yaks aged 3, 4, 5, and 6 months old were selected to collect fresh feces before and after weaning. Through 16S rRNA and ITS high-throughput sequencing, the dynamic distribution and potential function of yak fecal, bacterial, and fungal communities in each month were revealed. The study found that the richness of fungi had a significant impact on weaning. At the phylum level, Firmicutes, Bacteroidetes, Ascomycota, and Basidiomycota, and at the genus level, 5-7N15, Oscillospira, Roseburia, Dorea, Preussia, Neoascochyta, Naganishia, and Sporormiella were enriched in yak feces of different months old. The abundance and proportion of bacteria Firmicutes, Bacteroidetes, 5-7N15, and fungi Mucoromyceta changed significantly before and after weaning. With the increase of months, Verrucomicrobia and Akkermansia have shown a downward trend. Through the prediction and analysis of fecal microbial function, it was found that at the level of primary pathways, weaning has a significant impact on cellular processes, environmental information processing, genetic information processing, metabolism, and organismal systems. At the level of secondary metabolic pathways, weaning has a significant impact on cell motility, signal transduction, folding, sorting and degradation, translation, amino acid metabolism, glycan biosynthesis and metabolism, metabolism of terpenoids and polyketides, and xenobiotics biodegradation and metabolism. In addition, by analyzing the differences in functional pathways and microbial composition between sample groups of different months, it was found that the differences in functional pathways were related to the abundance differences of some microorganisms. In general, the changes in the composition and structure of yak fecal microflora may reflect the adaptability of the intestinal microbiota.

Figure 1

Fecal microbial amplicon sequence variants (ASVs) in different months. (a) Bacterial Venn diagram, where the overlapping area represents the number of ASVs shared between overlapping groups. (b) Fungal Venn diagram. (c) Bacteria rarefaction curves for each sample. (d) Fungal rarefaction curves for each sample. A: at 3 months; B: at 4 months; C: at 5 months; and D: at 6 months.

Figure 2

The composition of fecal bacteria in yaks of different months at phylum and genus levels. (a) Relative abundance of different phylum in samples of different months. (b) Relative abundance of different genus in samples of different months.

Figure 3

The composition of fecal fungal in yaks of different months at phylum and genus levels. (a) Relative abundance of different phyla in samples of different months. (b) Relative abundance of different genus in samples of different months.

Figure 4

Histogram showing taxa with statistically significantly LDA values of yaks at different ages. (a) LEfSe analysis of fecal bacterial communities. (b) LEfSe analysis of fecal fungal communities. f: family; g: genus; s: species; o: order.

Figure 5

Prediction of potential functions of fecal fungi from yaks of different ages. (a) Predictive functional components (%) of fecal fungi in yaks of different months of age at level 1. (b) Predictive functional components (%) of fecal fungi in yaks of different months of age at level 2.

Figure 6

Analysis of different functional pathways and species composition of yaks in different months. (a) Analysis of metabolic pathways in 4-month-old and 3-month-old yaks. (b) Species composition of GLUCOSE1PMETAB-PWY, glucose, and glucose-1-phosphate. (c) Analysis of metabolic pathways in 5-month-old and 4-month-old yaks. (d) Species composition of PWY-7374,1,4-dihydroxy-6-naphthoate biosynthesis I. (e) Species composition of PWY-6107 chlorosalicylate degradation. (f) Species composition of P341-PWY glycolysis V (Pyrococcus). (g) Analysis of metabolic pathways in 6-month-old and 5-month-old yaks. (h) Species composition of PWY-7446 sulfoglycolysis.