| Address |
State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education, Gansu Tech Innovation Center of Western China Grassland Industry, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, P.R. China |
| Abstract |
Achnatherum inebrians, a perennial grass, is widely distributed
in China. When infected by the endophyte Epichloë
gansuensis, A. inebrians produces an abundance of alkaloids
that enhance plant survival but are toxic to animals. Here
we used in vitro fermentation to study the impact of endophyte-
infected A. inebrians (E+) addition on rumen fermentation
characteristics and on microbial community and diversity
as assessed with amplicon sequencing technology.
We examined E+ addition at five levels, E0, E25, E50, E75,
and E100, corresponding to 0%, 25%, 50%, 75%, and 100%
of the fermentation substrate, respectively. Both the fermentation
characteristics and rumen microbial community structure
differed significantly among treatments. E100 resulted
in the highest values for pH, the Shannon index, Kiritimatiellaeota,
and Lentisphaerae levels relative to the other treatments.
In contrast, E25 was associated with higher levels of
ammonia nitrogen, total volatile fatty acid, propionate, butyrate,
isobutyrate, valerate, of the phyla Bacteroidetes and
Firmicutes, and of the genus Prevotella_1, Succiniclasticum,
Family_XIII_AD3011_group, Rikenellaceae_RC9_gut_group,
Prevotellaceae_UCG-001, and Pyramidobacter as compared
with other treatments. E50 resulted in the greatest values
for the abundance-based coverage estimator (ACE) and the
Chao1 index as compared with other treatments. E0 resulted
in the greatest values for digestibility of dry matter, gas production,
acetate, and Ruminobacter as compared with other
treatments. This approach avoided animal toxicity experiments
and confirmed that rumen fermentation characteristics and
rumen microbiota were affected by E+ toxin. Therefore, E25
showed higher abundance in Prevotella_1, Prevotellaceae_
UCG-001, and Lachnospiraceae_XPB1014_group that implied
they should play significant roles in E+ alkaloids degradation.
And then, we can infer that rumen microorganisms should
function as an antidote with respect to this poisoning reaction
at moderate dietary percentages of E+. |
