Project description:Anaerobic digestion is a popular and effective microbial process for waste treatment. The performance of anaerobic digestion processes is contingent on the balance of the microbial food web in utilizing various substrates. Recently, co-digestion, i.e., supplementing the primary substrate with an organic-rich co-substrate has been exploited to improve waste treatment efficiency. Yet the potential effects of elevated organic loading on microbial functional gene community remains elusive. In this study, functional gene array (GeoChip 5.0) was used to assess the response of microbial community to the addition of poultry waste in anaerobic digesters treating dairy manure. Consistent with 16S rRNA gene sequences data, GeoChip data showed that microbial community compositions were significantly shifted in favor of copiotrophic populations by co-digestion, as taxa with higher rRNA gene copy number such as Bacilli were enriched. The acetoclastic methanogen Methanosarcina was also enriched, while Methanosaeta was unaltered but more abundant than Methanosarcina throughout the study period. The microbial functional diversity involved in anaerobic digestion were also increased under co-digestion.
Project description:In animal production, the use of probiotics supplements to promote animal health is increasing. The objective of this study was to assess the impact of probiotics administration on global gene expression in dairy cows. Lactating Holstein-Friesian cows (n=10) from the North Carolina Agricultural and Technical State University dairy herd were used for the study. Treatment was a 50 ml oral drench of FASTtrak microbial pack (Probiotics) (Conklin Company, Kansas City, MO) at the recommended dose in sterile endotoxin-free water or sterile endotoxin-free water only (control). This treatment was carried out for 60 days. Whole blood was collected at the beginning (Day 0) and end of the study (Day 60) for microarray analysis. We employed microarray expression profiling as a discovery platform to identify genes with potential association with probiotics supplementation in cows. Gene expression analysis identified 10,859 differentially expressed genes- 1168 upregulated genes and 9691 downregulated gene. Results for pathway analysis showed significant pathways associated with innate immunity such as the Toll-like receptor (TLR) pathway, inflammation response and Wingless (Wnt) signaling pathway. Real-time PCR was used to validate the expression of the Wnt signaling pathway and immune response genes. Probiotic treatment impacted global gene expression, and particularly, the expression of immune response and Wnt signaling pathway genes. Oral administration of probiotics to dairy cows impacts global gene expression and particularly the expression of innate immune genes in dairy cows.