Xylanase production through solid state fermentation by endophytes of the mopane tree (Colophospermum mopane) and...

Different studies showed the potential of endophytes as sources of enzymes and other valuable metabolites. In this study two xylanase producing endophytes, Bacillus sp ML6 and Aureobasidium sp. MS40, were isolated from the mopane tree (Colophospermum mopane), a plant native to southern Africa. Both organisms grew under solid-state culture and produced xylanases that are active and stable between 30 to 50 °C and in the acidic to neutral pH range. The whole solid-state culture was dried and used as enzyme source. When stored at room temperature, both enzymes retained 100% of their original activity after 323 days at room temperature. To test potential application as feed additives, the enzymes were mixed with a maize-based commercial chicken feed at a rate of 3,200 U/kg and fed to Cobb broilers. All experimental animals grew well indicating that the enzyme preparation had no negative impact on the animals. However, no weight gain was observed up on addition of the enzymes which may be a result of a low arabinoxylan content of the commercial corn feed used. Previous studies demonstrated that no weight gain was observed up on addition of xylanases to chicken feed prepared from corn varieties with low arabinoxylan content.