【摘要】 从云南腾冲火山热泉中筛选到一株产木聚糖酶芽孢杆菌YNUCCTCRQ1。其木聚糖酶的最适反应温度为80℃,最适pH值7.5。该木聚糖酶在pH值2～12、温度73℃以下比较稳定。Ca2+、K+、Mg2+、ED TA对该木聚糖酶有较强的促进作用,Co2+、Ni2+、Cu2+、Mn2+和Hg2+对该酶有较强的抑制作用。对该菌株16SrDNA的1471bp片段的序列分析结果表明,芽孢杆菌YNUCCTCRQ1与GeneBank中的嗜碱芽孢杆菌(Bacillushalodurans)C-125和DSM497T最为接近。更多还原

【Abstract】 An alkaliphilic strain namely YNUCCTCRQ1 of Bacillus sp.was isolated from hot spring of Tengchong,Yunnan.A 1 471 bp long fragment of 16S rDNA from the strain YNUCCTCRQ1 was sequenced and compared with closely related taxon in Gene Bank.The phylogenetic tree constructed by minimum evolution method indicated that YNUCCTCRQ1 was closely related to alkaliphilic B.halodurans C-125 and DSM 497T which produce xylanase. It was demonstrated that the YNUCCTCRQ1 xylanase was optimally active at pH value 7.5 and stable over a broad pH value range from 2 to 12.The optimum temperature for xylanase activity was 80 ℃ and the enzyme was relatively stable （below） 73 ℃.Co²⁺,Ni²⁺,Cu²⁺,Mn²⁺ and Hg²⁺ showed strong inhibition on the activity of the xylanase,while Ca²⁺,（K⁺,）Mg²⁺ and EDTA,bore a remarkable promotion on the enzyme activity.更多还原