Project description:Beef represents a major diet component and source of protein in many countries. With an increment demand for beef, the industry is currently undergoing changes towards natural produced beef. Consumers not only concern about product quality, but also for the well-being of animals. Therefore, the consumption of grass-fed meat is continuously growing. However, the nutritional true differences between feeding systems are still unclear. The aim of this study was to examine latissimus dorsi muscle quality and animal welfare by transcriptome and metabolome profiles, and to identify biological pathways related to the differences between grass- and grain-fed Angus steers. By RNA-Seq analysis of latissimus dorsi muscle, we have recognized 241 differentially expressed genes (FDR < 0.1). The metabolome examination of muscle and blood revealed 163 and 179 altered compounds in each tissue (P-value < 0.05), respectively. Accordingly, alterations in glucose metabolism, divergences in free fatty acids and carnitine conjugated lipid levels, and altered β-oxidation, have been observed. In summary, this study demonstrates a unique transcriptomic and metabolic signature in the muscle of grain and grass finished cattle. Results support the accumulation of anti-inflammatory n3 polyunsaturated fatty acids in grass finished cattle, while higher levels of n6 PUFAs in grain finished animals may promote inflammation and oxidative stress. Furthermore, grass-fed animals produce tender beef with lower total fat and higher omega3/omega6 ratio than grain fed animals, which could potentially benefit consumer health. Finally, blood cortisol levels strongly indicate that grass fed animals experience less stress than the grass fed individuals The steers came from a closed Wye Angus herd with very similar genetics. The grass-fed group was comprised of steers that received alfalfa and orchard grass hay, clover and orchard grass pasture, or orchard grass and alfalfa pasture. The grass-fed individuals consumed grazed alfalfa upon availability and bales during winter and were not exposed to any corn, any form of grain or feed by-products. The alfalfa and grass hay were harvested from land that has had minimal fertilizer and no application of pesticides or inorganic chemicals. The control group was fed a conventional diet consisting of corn silage, soybean, shelled corn and minerals. The pastures were managed as organic landsâwithout fertilizers, pesticides or any chemical additives. At the slaughter plant, 10 ml whole blood sample from the jugular vein was collected in EDTA tubes and directly storage at -80°C. Then, a small piece of longissimus dorsi muscle was obtained from each hot carcass at the level of the 12th intercostal space and immediately frozen in dry ice for posterior analysis.
Project description:Functional redundancy in bacterial communities is expected to allow microbial assemblages to survive perturbation by allowing continuity in function despite compositional changes in communities. Recent evidence suggests, however, that microbial communities change both composition and function as a result of disturbance. We present evidence for a third response: resistance. We examined microbial community response to perturbation caused by nutrient enrichment in salt marsh sediments using deep pyrosequencing of 16S rRNA and functional gene microarrays targeting the nirS gene. Composition of the microbial community, as demonstrated by both genes, was unaffected by significant variations in external nutrient supply, despite demonstrable and diverse nutrient–induced changes in many aspects of marsh ecology. The lack of response to external forcing demonstrates a remarkable uncoupling between microbial composition and ecosystem-level biogeochemical processes and suggests that sediment microbial communities are able to resist some forms of perturbation.
Project description:Functional redundancy in bacterial communities is expected to allow microbial assemblages to survive perturbation by allowing continuity in function despite compositional changes in communities. Recent evidence suggests, however, that microbial communities change both composition and function as a result of disturbance. We present evidence for a third response: resistance. We examined microbial community response to perturbation caused by nutrient enrichment in salt marsh sediments using deep pyrosequencing of 16S rRNA and functional gene microarrays targeting the nirS gene. Composition of the microbial community, as demonstrated by both genes, was unaffected by significant variations in external nutrient supply, despite demonstrable and diverse nutrient–induced changes in many aspects of marsh ecology. The lack of response to external forcing demonstrates a remarkable uncoupling between microbial composition and ecosystem-level biogeochemical processes and suggests that sediment microbial communities are able to resist some forms of perturbation. nirS gene diversity from two salt marsh experiments, GSM (4 treatments, 8 samples, duplicate arrays, four replicate blocks per array, 8 arrays per slide) and PIE (2 treatments, 16 samples, duplicate arrays four replicate blocks per array, 8 arrays per slide)
Project description:In this study, microbial communities from triplicate leach-bed anaerobic bioreactors digesting grass were analysed. Each reactor comprised two microbial fractions, one immobilized on grass (biofilm) and the other in a planktonic state present in the leachate. Microbial communities from the two fractions were systematically investigated for community composition and function. This was carried out using DNA, RNA and protein co-extraction. The microbial structure of each fraction was examined using 16S rRNA deep sequencing, while the active members of the consortia were identified using the same approach on cDNA generated from co-extracted RNA samples. Microbial function was investigated using a metaproteomic workflow combining SDS-PAGE and LC-MS/MS analysis.
Project description:To determine whether and how warming affects the functional capacities of the active microbial communities, GeoChip 5.0 microarray was used. Briefly, four fractions of each 13C-straw sample were selected and regarded as representative for the active bacterial community if 16S rRNA genes of the corresponding 12C-straw samples at the same density fraction were close to zero.
Project description:The aim was to determine the changes in cell wall composition and transcriptome changes following treatment with the stress hormone precursor methyl jasmonate (MeJA) in the model grass Brachypodium distachyon. The correlation between transcript changes and cell wall composition changes allowed identification of candidate genes responsible for grass-specific features of the cell wall that are specifically changed in response to MeJA.