琼斯氏菌(Jonesia sp.)YNUCC0043耐碱木聚糖酶的特性

Production of Alkaline Xylanase by a Newly Isolated Alkaliphilic Jonesia sp. Strain YNUCC0043

从造纸黑液中筛选到一株产木聚糖酶琼斯氏菌YNUCC0043。在含3％玉米芯和0．5％牛肉膏的碱性无机盐培养基中，发酵液木聚糖酶活力达48．50U／ml。其木聚糖酶的最适反应温度为60℃，最适pH值8.0。该木聚糖酶在pH值6-11，温度60℃以下比较稳定。对该菌株16SrDNA的1456bp片段的序列分析结果表明，琼斯氏菌YNUCC0043与青海琼斯氏菌DSM15701和琼斯氏菌SC06的系统发育关系最近。

An alkaliphilic strain YNUCC0043 of Jonesia sp was isolated from black liquor of paper mill. A 1456bp long fragment of 16S rDNA from the strain YNUCC0043 was sequenced and compared with closely related taxon in GenBank. The phylogenetic tree constructed by Minimum Evolution and Maximum Parsimony methods indicated that YNUCC0043 was closely related to Jonesia sp. SC06 and Jonesia quinghaiensis DSM 15701. The optimum conditions for production of xylanolytic enzymes from alkaliphilie Jonesia sp. YNUCC0043 was performed in shake flasks. When the bacterium was grown in the alkaline mineral salt medium using 3% of corncob and 0.5% of beef extract as carbon source and nitrogen source, respectively, 48.50 U/ml xylanase activity was detected in the culture supernatant. It was demonstrated that the YNUCC0043 xylanase was optimally active at pH value 8.0 and stable over an pH range from pH value 6 to pH value 11. The optimum temperature for xylanase activity was 60℃ and the enzyme was relatively stable blow 60℃.