CONICET | Buscador de Institutos y Recursos Humanos

In the NE of Mendoza (Argentina), the diet of Creole goats is composed basically with high proportion of shrub species, which constitute an important source of vegetable fibers. The high efficiency in the utilization of fiber by goats may be due, in part, to the characteristics of ruminal fibrolytic bacteria and their enzymes. Therefore, the study of bacterial populations and their enzymes in goat rumen become a priority for improving the breeding of these ruminants. Recently, we have isolated and characterized Pseudobutyrivibrio xylanivorans from rumen of Creole goats. Moreover, we have identified the xynAPx gene to encoding glycosyl hydrolase enzymes and measured enzyme activity related to the presence of this gene. This activity was related to the ruminal bacterial species involved in the digestion of xylan, a major component of hemicellulose contained in the wall of plant cells. Based on these findings, we propose the use of P. xylanivorans as probiotic bacteria. Bacteria with probiotic capability synthesize hydrolytic enzymes for an efficient digestion of fibers. This study was performed to determine the degradation and utilization of hemicellulose from intact forages by P. xylanivorans. Fermentations by pure culture were run to completion by using alfalfa hay and native forages selected by goats grazing. Degradation was defined as the solubilization of 80% ethanol-insoluble pentose, whereas utilization was defined as a loss in total pentose. The nutritional components measured from intact forages were cutin, neutral detergent fiber, acid detergent fiber, acid detergent lignin, hemicellulose, cellulose, crude protein and starch. A. lampa showed the maximum (p