【摘要】 从云南洱源县热泉中分离到一株产木聚糖酶嗜热真菌ThermomyceslanuginosusYNUCC4 15 4 .对其 2 8SrD NA的 5′端约 90 0bp的片段进行了扩增和测序 ,并与GenBank中最相似的 12个分类单位进行了比较 .邻近接合法构建的系统发育树显示 ,T .lanuginosusYNUCC4 15 4与几个产木聚糖酶的嗜热真菌关系较近 .在 30L全自动发酵罐中5 5℃发酵 5 0h后 ,木聚糖酶酶活达 10 32UmL-1.该木聚糖酶最适反应温度为 73℃ ,最适pH为 6 .5 ,在 10～ 6 7℃和pH 3～ 12时比较稳定 ,表明这是一种热稳定耐碱木聚糖酶 ,在造纸工业中具有良好的应用前景 .图 7表 1参 2 4更多还原

【Abstract】 A strain namely YNUCC4154 of Thermomyces lanuginosus was isolated from a hot spring in Eryuan,Yunnan. Sequenced 28S rDNA fragment from T. lanuginosus YNUCC4154 was compared with closely related taxon in GenBank. The phylogenetic tree constructed by neighbor-joining method indicated that T. lanuginosus YNUCC4154 was closely related to several thermophilic fungi which produce xylanase. The strain YNUCC4154 produced a maximum amount of xylanase (1 032 U mL -1) in 30 L-BIOSTATNA14C C Fermentor at 55 ℃ for 50 h. The crude xylanase exhibited the highest activity at pH 6.5 and at the temperature 73 ℃. Xylanase was stable over at an abroad pH range between pH 3.0～pH 12 and at temperature up to 67 ℃. Hg 2+,Cu 2+ and Mn 2+ showed strong inhibition on the activity of the xylanase, while K +, Ca 2+ and Mg + born a remarkable promotion on the enzyme activity. The xylanase is a thermostable alkali-tolerant xylanase with potential value for pulp process in paper industry. Fig 7, Tab 1, Ref 24更多还原