Exploring rumen microbe-derived fibre degrading activities for improving feed digestibility

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dc.contributor.authorMoon, CDen_US
dc.contributor.authorGagic, Den_US
dc.contributor.authorCiric, Men_US
dc.contributor.authorNoel, Sen_US
dc.contributor.authorSummers, ELen_US
dc.contributor.authorLi, Den_US
dc.contributor.authorAtua, RMLen_US
dc.contributor.authorPerry, Ren_US
dc.contributor.authorSang, Cen_US
dc.contributor.authorZhang, YLen_US
dc.contributor.authorSchofield, LRen_US
dc.contributor.authorLeahy, SCen_US
dc.contributor.authorAltermann, Een_US
dc.contributor.authorJanssen, PHen_US
dc.contributor.authorArcus, VLen_US
dc.contributor.authorKelly, WJen_US
dc.contributor.authorWaghorn, GCen_US
dc.contributor.authorRakonjac, Jen_US
dc.contributor.authorAttwood, GTen_US
dc.contributor.editorRoche, Jen_US
dc.coverage.spatialHamilton, New Zealanden_US
dc.date.available2014en_US
dc.date.finish-date2014-11-21en_US
dc.date.issued2014en_US
dc.date.start-date2014-11-19en_US
dc.description.abstractcrucial for optimal dairy productivity. Enzymes produced by rumen microbes are primarily responsible for degrading the complex structural polysaccharides that comprise fibre in the plant cell walls of feed materials. Because rumen microbes have evolved with their ruminant hosts over millions of years to perform this task, their enzymes are hypothesised to be optimally suited for activity at the temperature, pH range, and anaerobic environment of the rumen. However, fibre-rich diets are not fully digested, which represents a loss in potential animal productivity. Thus, there is opportunity to improve fibre utilisation through treating feeds with rumen microbe-derived fibrolytic enzymes and associated activities that enhance fibre degradation. This research aims to gain a better understanding of the key rumen microbes involved in fibre degradation and the mechanisms they employ to degrade fibre, by applying cultivation-based and culture-independent genomics approaches to rumen microbial communities of New Zealand dairy cattle. Using this knowledge, we aim to identify new opportunities for improving fibre degradation to enhance dairy productivity. Rumen content samples were taken over the course of a year from a Waikato dairy production herd. Over 1,000 rumen bacterial cultures were obtained from the plant-adherent fraction of the rumen contents. Among these cultures, two, 59 and 103 potentially new families, genera and species of rumen bacteria were identified, respectively. Many of the novel strains are being genome sequenced within the Hungate 1000 rumen microbial reference genome programme, which is providing deeper insights into the range of mechanisms used by the individual strains for fibre degradation. This information has been used to guide the selection of rumen bacterial strains with considerable potential as fibrolytic enzyme producers in vitro, with the intent of developing the strains so that their enzymes may be used as feed pre-treatments for use on farm. Culture-independent metagenomic approaches were also used to explore the activities involved in fibre degradation from the rumen microbial communities. Functional screening has revealed a range of novel enzymes and a novel fibre disrupting activity. Enrichment for the cell-secreted proteins from the community revealed evidence of a diverse range of cellulosomes, which are cell-surface associated multi-enzyme complexes that efficiently degrade plant cell wall polysaccharides. Biochemical and structural characterisation of these proteins has been conducted. In conclusion, cultivation and culture-independent genomic approaches have been applied to New Zealand bovine rumen microbial communities, and have provided considerable new insights into ruminal fibre degradation processes. Novel activities and bacterial species that display desirable activities on fibrous substrates in vitro are now being explored for their potential to improve ruminal fibre degradation, to allow the development of new technologies that will enhance dairy productivityen_US
dc.description.confidentialfalseen_US
dc.format.extent377 - 379en_US
dc.identifier.citationProceedings of the 5th Australasian Dairy Science Symposium 2014, 2014, pp. 377 - 379en_US
dc.identifier.elements-id260075
dc.identifier.harvestedMassey_Dark
dc.publisherAustralasian Dairy Science Symposiumen_US
dc.relation.isPartOfProceedings of the 5th Australasian Dairy Science Symposium 2014en_US
dc.relation.urihttp://www.adssymposium.com.au/inewsfiles/2014proceedings/ADSS2014_FULL.pdfen_US
dc.sourceAustralasian Dairy Science Symposium 2014en_US
dc.subjectDigestibilityen_US
dc.subjectenzymesen_US
dc.subjectfibreen_US
dc.subjectnutritionen_US
dc.subjectplant cell wallsen_US
dc.subjectrumen microbesen_US
dc.subjectsupplemental feedsen_US
dc.titleExploring rumen microbe-derived fibre degrading activities for improving feed digestibilityen_US
dc.typeConference Paper
pubs.notesNot knownen_US
pubs.organisational-group/Massey University
pubs.organisational-group/Massey University/College of Sciences
pubs.organisational-group/Massey University/College of Sciences/School of Natural Sciences
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