Taxonomy & phylogeny Eubacterium eligens is a member of the
Bacillota (previously
Firmicutes) phylum, which is one of two phyla which constitute more than 90% of microflora in the human gut. Characteristics of this phylum include low GC content in the DNA and
Gram-positivity. Within the class
Clostridia,
E. eligens is placed in the order
Clostridiales, which includes a large variety of
anaerobic bacteria with varying metabolic capabilities.
E. eligens is a member of the
Eubacterium genus, a phylogenetically and phenotypically diverse genus. The genus was first proposed in 1938 by French bacteriologist
Prévot, grouping together beneficial bacteria from human feces. This finding prompted the potential renaming of
E. eligens to
Lachnospira eligens. Holdeman and Moore worked in the Anaerobe Lab at Virginia Tech where they were able to isolate and define almost 200 new microbes from the
human intestinal tract.
E. eligens was isolated and described alongside 12 other unknown
anaerobic species after being discovered during studies of the human fecal flora. Characterization was based on growth on or reaction to 32 different
substrates by the isolated bacterium. BacDive establishes that
E. eligens performs
arginine and
urea hydrolysis,
nitrate reduction, and utilizes
tryptophan as an energy source. What is known about the metabolism of
E. eligens generally centers around its ability to break down
carbohydrates, which makes it
heterotrophic. Studies have shown that bacteria in the gut microbiota – which is where
E. eligens can be found – interact with carbohydrates. In terms of testing the carbon acquisition of
E. eligens specifically, other studies have shown this species outcompete other species in piglet fecal samples when piglets were fed sugar beet pulp as well as
fructooligosaccharide, which were the only sources of carbon available to the gut microbiota. Additional research has also supported that this bacteria metabolizes the
pectin in sugar beets and apples, which is a
polysaccharide often found in fruit. Because of its metabolism, many of the
genes found and studied in
E. eligens focus on fermentation of carbohydrates. It has several genes that encode for
enzymes that are intended to break down various carbohydrates, especially pectin.
Genomics Eubacterium eligens has a total of 2,723
genes which constitute 2,613
protein genes, 66 RNA genes, and 44
pseudogenes. It consists of 2.83
Mb and can undergo 959 enzymatic reactions. The
Eubacterium species
E. rectale,
E. hallii, E. ventriosum, E. eligens, E. coprostanoligenes, and
E. limosum are the most closely related to one another with DNA
G+C content of the genus varying from 30 to 57 percent. Kageyama and Benno found success in using
nested PCR, a universal primer pair, and subsequent amplification of the bacterial sample using species-specific primers. The scientists used an assembler known as Athena, which builds high-quality genome drafts from a single shotgun sequencing operation by using barcode information from read clouds. == Applications ==