OPTIMIZATION OF SOME CULTURE CONDITIONS FOR ASPERGILLUS ORYZAE DSM1863 AND ASPERGILLUS NIGER DSM1957 PRODUCING XYLANASE

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Abstract

Xylan is a β-1,4-linked polymer of xylose, often with 4-0-methylglucuronate and arabinose side chains, and is located in cell wall of higher plants, especially hardwoods and grasses. It is hydrolyzed by a combination of endoxylanase (1-4-D-xylan xylanohydrolase, EC 3.2.1.8) and 3-xylosidase (EC 3.2.1.37), produced by many bacteria and fungi. In this study, some culture conditions for Aspergillus oryzae DSMl863 and Aspergillus niger DSMI957 producing xylanase were optimized. Xylanase production of the fungus A. oryzae DSM 1863 was 8 times as high as that of the fungus strain A. niger DSM 1957. Highest xylanase production of both strains was obtained after 72 h of cultivation. Corncob induced maximum production of the xylanase in both strains Aspergillus in comparison to other tested carbon sources (bagasse, com cob, rice bran, soybean shell, dried mandarin shell and xylan). Corncob with the concentration of 5% and 4% induced the strain A. niger DSMI957 and A. oryzae DSMI863 producing xylanase maximum with an activity of 23 U/ml and 123 U/ml, respectively. Soybean powder was the best nitrogen source among nitrogen sources tested (NH4)2S04. fish powder, soybean powder, meat paste, casein and peptone) for xylanase production of both strains Aspergillus. The fungi A. niger DSMI957 and A. oryzae DSMI863 produced xylanase with a highest activity of 19 and 76 U/ml in media contained 2% and 1% soybena powder, respectively. Both fungi Aspergillus strain produced xylanase maximum at the temperature of 30°C and pH 7 and cultivation time of 72 hours. These both enzymes were purified and characterized

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Đỗ Thị Tuyên
điểm /   đánh giá
Published
2011-11-25
Section
Articles