Degradation of forage chicory by ruminal fibrolytic bacteria

Abstract

Aims: Determine the susceptibility of forage chicory (Cichorium intybus L.) to degradation by ruminal fibrolytic bacteria and measure the effects on cell‐wall pectic polysaccharides. Methods and Results: Large segments of fresh forage chicory were degraded in vitro by Lachnospira multiparus and Fibrobacter succinogenes, but not by Ruminococcus flavefaciens or Butyrivibrio hungatei. Cell‐wall pectins were degraded extensively (95%) and rapidly by L. multiparus with a simultaneous release of uronic acids and the pectin‐derived neutral monosaccharides arabinose, galactose and rhamnose. Fibrobacter succinogenes also degraded cell‐wall pectins extensively, but at a slower rate than L. multiparus. Immunofluorescence microscopy using monoclonal antibodies revealed that, after incubation, homogalacturonans with both low and high degrees of methyl esterification were almost completely lost from walls of all cell types and from the middle lamella between cells. Conclusions: Only two of the four ruminal bacteria with pectinolytic activity degraded fresh chicory leaves, and each showed a different pattern of pectin breakdown. Degradation was greatest for F. succinogenes which also had cellulolytic activity. Significance and Impact of the Study: The finding of extensive removal of pectic polysaccharides from the middle lamella and the consequent decrease in particle size may explain the decreased rumination and the increased intake observed in ruminants grazing forage chicory.

A metagenomic analysis of the camel rumen’s microbiome identifies the major microbes responsible for lignocellulose degradation and fermentation

“…However, they were diverse with respect to both CBMs and PLs. F. succinogenes is a fibrolytic and pectin-degrading species capable of utilizing cellulose as its sole energy source [ 49 , 50 ], highlighting its potential as a lignocellulose degrader in the camel rumen. The Spirochaetes bins (#174, #101 and #103) harbored genes encoding members of 36 GH families, of which the most frequently occurring were GH3, GH13, GH23, GH43, GH51, GH57 and GH77.…”

“…On this basis, the conclusion is that from a taxonomical viewpoint, the species composition of the camel rumen is not so dissimilar to that of either the bovine [ 13 , 16 , 20 ] or the moose [ 39 , 60 ] rumen. A notable difference, however, was the relatively strong representation of Fibrobacteres species, known to target plant fiber and pectin [ 49 , 50 ]. The presence of these microbes may reflect the uniqueness of the camel’s diet, which typically includes material having a high content of lignocellulose.…”

BOARD-INVITED REVIEW: St. Anthony's Fire in livestock: Causes, mechanisms, and potential solutions1,2

“…Indeed, the rumen flora degrade exogenous loline alkaloids both in vitro and in vivo (Westendorf et al, 1992), though metabolism of ergot alkaloids has not been shown definitively. However, rumen fermentation does release plant compoinids that are not primary metabolites (Sun et al, 2008). Toxicants, such as ergot alkaloids, appear to be among the compounds that are liberated by fermentation (Ayers et al, 2009).…”

Impact of chicory inclusion in a cereal-based diet on digestibility, organ size and faecal microbiota in growing pigs

“…No studies on the effects of chicory forage on the pig microbiota have yet been reported. An in vitro study using ruminal fibrolytic bacteria has shown that chicory forage is efficiently degraded by the pectinolytic bacteria Lachnospira multiparus and Fibrobacter succinogenes (Sun et al, 2008). The chicory root has a high content of inulin and fructo-oligosaccharides.…”