Degradation of pectic polysaccharides in forage chicory (Cichorium intybus L.) by rumen bacteria

摘要

In vitro degradation of fresh chicory (L.) leaves were studied using rumen bacteria Lachnospira multiparus (pectinolytic) and Fibrobacter succinogenes (cellulolytic). L. multiparus did not release cellulose- and "hemicellulose"-associated monosaccharides glucose, xylose or mannose, but released the rhamnogalacturonan-associated monosaccharides arabinose, galactose and rhamnose, and rapidly released homogalacturonan-associated monosaccharides uronic acids. F. succinogenes also released uronic acids extensively, but at a slower rate than L multiparus and also released glucose, xylose and mannose. F. succinogenes released these monosaccharides sequentially in the order uronic acid, rhamnose, and then arabinose and galactose together, suggesting that pectic polysaccharides degrade faster than cellulose and "hemicelluloses", among pectic polysaccharides homogalacturonan faster than rhamnogalacturonan I. It appears the degradation of pectic polysaccharides by rumen bacteria may contribute significantly to the high digestibility of forage chicory.