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Newly cultured bacteria with broad diversity isolated from eight-week continuous culture enrichments of cow feces on complex polysaccharides

Permanent URL:
http://handle.nal.usda.gov/10113/58712
File:
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Abstract:
One of the functions of the mammalian large intestinal microbiota is the fermentation of plant cell wall components. In ruminant animals, the majority of their nutrients are obtained via pregastric fermentation; however, up to 20% can be recovered from microbial fermentation in the large intestine. Eight-week continuous culture enrichments of cattle feces with cellulose and xylan-pectin were used to isolate bacteria from this community. A total of 459 bacterial isolates were classified phylogenetically using 16S rRNA gene sequencing. Six phyla were represented: Firmicutes (51.9%), Bacteroidetes (30.9%), Proteobacteria (11.1%), Actinobacteria (3.5%), Synergistetes (1.5%), and Fusobacteria (1.1%). The majority of bacterial isolates had <98.5% identity to cultured bacteria with sequences in the Ribosomal Database Project and thus represent new species and/or genera. Within the Firmicutes isolates, most were classified in the families Lachnospiraceae, Ruminococcaceae, Erysipelotrichaceae, and Clostridiaceae I. The majority of the Bacteroidetes were most closely related to Bacteroides thetaiotaomicron, B. ovatus, and B. xylanisolvens and members of the Porphyromonadaceae family. Many of the Firmicutes and Bacteroidetes isolates were related to species demonstrated to possess enzymes which ferment plant cell wall components; the others were hypothesized to cross-feed these bacteria. The microbial communities that arose in these enrichment cultures had broad bacterial diversity. With over 98% of the isolates not represented as previously cultured, there are new opportunities to study the genomic and metabolic capacities of these members of the complex intestinal microbiota.
Author(s):
Cherie J. Ziemer
Subject(s):
Actinobacteria , Bacteroides thetaiotaomicron , Clostridiaceae , Fusobacteria , Proteobacteria , bacteria , cell wall components , cellulose , cows , enzymes , feces , fermentation , genes , intestinal microorganisms , large intestine , microbial communities , new species , nucleotide sequences , nutrients , pectins , ribosomal RNA , species diversity , xylan
Note:
USDA Scientist Submission
Source:
Applied and environmental microbiology 2013 11 8 v.80 no.2
Language:
English
Year:
2013
Collection:
Journal Articles, USDA Authors, Peer-Reviewed
Rights:
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.