Degradation and utilization of hemicellulose from intact forages by Pseudobutyrivibrio xylanivorans.

GRILLI, D.; EGEA, V.; CERÓN, M.; PAEZ LAMA, S.; CARCAÑO, D.; ALLEGRETTI, L.; ARENAS, GN.

Mendoza

Jornada; XXXI Reunión Científica Anual de la Sociedad de Biología de Cuyo.; 2013

Sociedad de Biología de Cuyo

In NE of Mendoza, goats compose their diet with a predominance of native shrub species, such as Prosopis flexuosa, Atriplex lampa, Tricomaria usillo, Geoffroea decorticans, Mimosa ephedroides and Capparis atamisquea, which constitute an important source of vegetable fiber. From rumen of these goats, we isolated to Pseudobutyrivibrio xylanivorans, involved in ruminal digestion of fiber. 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. Hemicellulose concentration of the forages was estimated by hydrolysis in H2S04 and measurement of total pentose present with the orcinol reaction. 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 crude protein, neutral detergent fiber, acid detergent fiber, acid detergent lignin (ADL), and starch. A. lampa showed the maximum degradation value (61.2 ± 1.0%) and utilization (52.5 ± 4.5%) of hemicellulose and G. decorticans showed the lower value of degradation (27.5 ± 2.4%), in comparison with alfalfa hay. The correlation coefficient (R2=-0.79, p