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As yet uncultured bacteria phylogenetically classified as Prevotella , Lachnospiraceae incertae sedis and unclassified Bacteroidales , Clostridiales and Ruminococcaceae may play a predominant role in ruminal biohydrogenation
Author(s) -
Huws Sharon A.,
Kim Eun J.,
Lee Michael R. F.,
Scott Mark B.,
Tweed John K. S.,
Pinloche Eric,
Wallace R. John,
Scollan Nigel D.
Publication year - 2011
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2011.02452.x
Subject(s) - lachnospiraceae , biology , rumen , clostridiales , prevotella , microbiology and biotechnology , temperature gradient gel electrophoresis , conjugated linoleic acid , bacteria , food science , fatty acid , 16s ribosomal rna , biochemistry , linoleic acid , genetics , fermentation , firmicutes
Summary Microbial biohydrogenation of dietary poly‐unsaturated fatty acids (PUFA) to saturated fatty acids (SFA) in the rumen results in the high ratio of SFA/PUFA in ruminant products, such as meat and milk. In vitro , Butyrivibrio proteoclasticus ‐related bacteria extensively biohydrogenate PUFA to SFA, yet their contribution in the rumen has not been confirmed. The aim of this study was to evaluate the role of Butyrivibrio proteoclasticus group bacteria in ruminal biohydrogenation and to assess the possible role of other bacteria. Fish oil at 0%, 1.5% and 3% dry matter intake was fed to eight Holstein × Friesian steers, in order to elicit changes in the extent of PUFA biohydrogenation. Fatty acid and B. proteoclasticus group 16S rRNA concentrations in rumen digesta were determined. Correlation between digesta 18:0 concentration and B. proteoclasticus group 16S rRNA concentration was low. Terminal restriction fragment length polymorphism and denaturing gradient gel electrophoresis (DGGE) coupled with multivariate statistics revealed that many terminal restriction fragments (T‐RFs) and DGGE bands were linked to cis ‐9, trans ‐11 conjugated linoleic acid (CLA), 18:1 trans ‐11 and 18:0 ruminal concentrations. MiCA T‐RF predictive identification software showed that these linked T‐RFs were likely to originate from as yet uncultured bacteria classified as Prevotella , Lachnospiraceae incertae sedis, and unclassified Bacteroidales , Clostridiales and Ruminococcaceae. Sequencing of linked DGGE bands also revealed that as yet uncultured bacteria classified as Prevotella , Anaerovoax (member of the Lachnospiraceae incertae sedis family), and unclassified Clostridiales and Ruminococcaceae may play a role in biohydrogenation.