English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Background  Bacteria in the genus  Ruminococcus  are ubiquitous members of the mammalian gastrointestinal tract. In particular, they are important in ruminants where they digest a wide range of plant cell wall polysaccharides. For example,  Ruminococcus albus  7 is a primary cellulose degrader that produces acetate usable by its bovine host. Moreover, it is one of the few organisms that ferments cellulose to form ethanol at mesophilic temperatures  in vitro . The mechanism of cellulose degradation by  R. albus  7 is not well-defined and is thought to involve pilin-like proteins, unique carbohydrate-binding domains, a glycocalyx, and cellulosomes. Here, we used a combination of comparative genomics, fermentation analyses, and transcriptomics to further clarify the cellulolytic and fermentative potential of  R. albus  7.    Results  A comparison of the  R. albus  7 genome sequence against the genome sequences of related bacteria that either encode or do not encode cellulosomes revealed that  R. albus  7 does not encode for most canonical cellulosomal components. Fermentation analysis of  R. albus  7 revealed the ability to produce ethanol and acetate on a wide range of fibrous substrates  in vitro . Global transcriptomic analysis of  R. albus  7 grown at identical dilution rates on cellulose and cellobiose in a chemostat showed that this bacterium, when growing on cellulose, utilizes a carbohydrate-degrading strategy that involves increased transcription of the rare carbohydrate-binding module (CBM) family 37 domain and the tryptophan biosynthetic operon.    Conclusions  Our data suggest that  R. albus  7 does not use canonical cellulosomal components to degrade cellulose, but rather up-regulates the expression of CBM37-containing enzymes and tryptophan biosynthesis. This study contributes to a revised model of carbohydrate degradation by this key member of the rumen ecosystem.    Electronic supplementary material  The online version of this article (doi:10.1186/1471-2164-15-1066) contains supplementary material, which is available to authorized users.

Unique aspects of fiber degradation by the ruminal ethanologen Ruminococcus albus 7 revealed by physiological and transcriptomic analysis