Fractionation of crude pentosanase (arabinoxylanase) for improvement of the nutritional value of rye diets for broiler chickens
1989
Groot Wassink, J.W.D. | Campbell, G.L. | Classen, H.L.
A pentosanase component of a crude enzyme product was concentrated and added to chick diets. Four levels of purity were examined: (a) the crude enzyme product, (b) a crude water extract, (c) a pentosanase purified using ion-exchange chromtography (non-bound fraction), and (d) residual pentosanase eluted with 0.4 M NaCl salt from the ion-exchange column (salt-eluted fraction). All preparations exhibited high viscosity-reduction capabilities when tested against a soluble pentosan preparation isolated from rye grain. The absence of arabinose release during rapid viscosity reduction of pentosan indicated that the non-bound pentosanase was an endoxylanase (1,4-beta-D-xylan xylanohydrolase, EC 3.2.1.8) without alpha-L-arabino-furanosidase activity. When added to broiler chick diets containing rye as the only cereal, all enzyme preparations significantly improved growth and feed conversion. At equivalent viscosity-reduction activity the non-bound pentosanase was less effective than other preparations, suggesting that multiple enzymes may be necessary to elicit maximum benefit. Alternatively, since the non-bound enzyme was less pH stable it may have lost activity in the acidic environment of the foregut.
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