Submitted to: Public Library of Science Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 28, 2011
Publication Date: January 12, 2012
Citation: Li, R.W., Wu, S., Li, W., Baldwin, R.L., Li, C. 2012. Perturbation dynamics of the rumen microbiota in response to exogenous butyrate. Public Library of Science Biology. 7(1):e29392. DOI:10.1371/journal.pone.0029392. Interpretive Summary: The rumen microbiota plays an essential role in nutrient production and utilization in cattle. Efficient microbial transformation of plant fibers results in production of various small molecules, which are subsequently used to produce meat and milk for human consumption. Understanding of microbial interactions and dynamics in the rumen microbial ecosystem provides a scientific basis for successful manipulation of ruminal fermentation for optimal outcomes. In this study, we characterized temporal changes of the rumen microbiota of dairy cows in response to an exogenous butyrate disturbance. Our results demonstrate that butyrate perturbation had a profound impact on resistance and resilience of the rumen microbial ecosystem and significantly altered the relative abundance of 19 genera and 43 species. Our findings provide insight into perturbation dynamics of the rumen microbial ecosystem and should guide efforts in formulating optimal uses of probiotic bacteria in enhancing ruminal fermentation and treating human diseases.
Technical Abstract: The capacity of the rumen microbiota to produce volatile fatty acids (VFA) has important implications in animal well-being and production. We investigated temporal changes of the rumen microbiota in response to butyrate infusion using pyrosequencing of the 16S rRNA gene. Phyla were identified in the rumen microbiota of dairy cows. The rumen microbiota harbored 54.5± 6.1 genera (mean ± SD) and 127.3 ± 4.4 operational taxonomic units (OTU), respectively. However, the core microbiome comprised of 26 genera and 82 OTU. Butyrate infusion altered molar percentages of 3 major VFA. Butyrate perturbation had a profound impact on the rumen microbial composition. A 72h-infusion led to a significant change in the abundance of 4 phyla, including 2 most abundant phyla, Bacteroidetes and Firmicutes. As many as 19 genera and 43 OTU were significantly impacted by butyrate infusion. Elevated butyrate levels in the rumen seemingly had a stimulating effect on butyrate-producing bacteria populations. The resilience of the rumen microbial ecosystem was evident as the abundance of the microorganisms returned to their pre-disturbed status after infusion withdrawal. Our findings provide insight into perturbation dynamics of the rumen microbial ecosystem and should guide efforts in formulating optimal uses of probiotic bacteria treating human diseases.