With the passage of time, energy sources are decreasing day by day. In order to meet the world's demand, much attention is being paid to the study of enzymes with xylanolytic activity as a potential means of generating energy. A thermophilic xylanolytic bacterium, Bacillus sp., was isolated from naturally decaying material by enrichment culture and serial dilution methods. The bacterium was grown in MH medium at 50°C and pH 7 for 10 h. The xylanolytic Bacillus sp. produced clear yellow haloes around the colonies in the presence of p-nitrophenyl beta-D-xylopyranoside (pNPX) as a substrate. After condition optimization, it was found that the organism produced the higher level of xylosidase activity after 14 h in the presence of arabinose as a carbon source and ammonium sulfate as a nitrogen source in the pH 7 medium of at 55°C. The maximum β-xylosidase activity after optimizing the culture condition was 5.0 U/mL. Later this thermophilic Bacillus sp. was used as a donor in cloning of the β-xylosidase gene. A genomic library of Bacillus sp. was prepared by digesting the genomic DNA of the Bacillus with the restriction endonuclease BamHI, ligating the fragments in the pUC18 cloning vector and then transforming the competent E. coli DH5α cells with the resultant chimeric plasmid. The β-xylosidase gene was identified by screening the transformants in duplicates on LB agar plates overlaid with pNPX as a substrate. Commercial production of β-xylosidase to be used as a methanol-producing enzyme can help to overcome fuel shortages.

中文翻译：

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嗜热木聚糖分解细菌芽孢杆菌属细菌的重组β-木糖苷酶的细菌表达和鉴定。

随着时间的流逝，能源日趋减少。为了满足世界的需求，对具有木聚糖分解活性作为产生能量的潜在手段的酶的研究受到了很多关注。通过富集培养和连续稀释法从自然腐烂的物质中分离出嗜热的木聚糖分解细菌芽孢杆菌。使细菌在MH培养基中于50°C和pH 7的条件下生长10小时。木聚糖分解芽孢杆菌。在对硝基苯基β-D-吡喃吡喃糖苷（pNPX）作为底物的存在下，在菌落周围产生了透明的黄色光环。条件优化后，发现该生物体在55℃的pH 7培养基中存在阿拉伯糖作为碳源和硫酸铵作为氮源的情况下14小时后产生了更高水平的木糖苷酶活性。优化培养条件后的最大β-木糖苷酶活性为5.0 U / mL。后来这个嗜热芽孢杆菌属。β-木糖苷酶基因的克隆被用作供体。芽孢杆菌属的基因组文库。通过用限制性核酸内切酶BamHI消化芽孢杆菌的基因组DNA，将片段连接到pUC18克隆载体中，然后用所得的嵌合质粒转化感受态大肠杆菌DH5α细胞，制备了DNA片段。通过在以pNPX为底物的LB琼脂平板上一式两份地筛选转化子来鉴定β-木糖苷酶基因。商业化生产用作甲醇生产酶的β-木糖苷酶可以帮助克服燃料短缺。β-木糖苷酶基因的克隆被用作供体。芽孢杆菌属的基因组文库。通过用限制性核酸内切酶BamHI消化芽孢杆菌的基因组DNA，将片段连接到pUC18克隆载体中，然后用所得的嵌合质粒转化感受态大肠杆菌DH5α细胞，制备了DNA片段。通过在以pNPX为底物的LB琼脂平板上一式两份地筛选转化子来鉴定β-木糖苷酶基因。商业化生产用作甲醇生产酶的β-木糖苷酶可以帮助克服燃料短缺。β-木糖苷酶基因的克隆被用作供体。芽孢杆菌属的基因组文库。通过用限制性核酸内切酶BamHI消化芽孢杆菌的基因组DNA，将片段连接到pUC18克隆载体中，然后用所得的嵌合质粒转化感受态大肠杆菌DH5α细胞，制备了DNA片段。通过在以pNPX为底物的LB琼脂平板上一式两份地筛选转化子来鉴定β-木糖苷酶基因。商业化生产用作甲醇生产酶的β-木糖苷酶可以帮助克服燃料短缺。大肠杆菌DH5α细胞与产生的嵌合质粒。通过在以pNPX为底物的LB琼脂平板上一式两份地筛选转化子来鉴定β-木糖苷酶基因。商业化生产用作甲醇生产酶的β-木糖苷酶可以帮助克服燃料短缺。大肠杆菌DH5α细胞与产生的嵌合质粒。通过在以pNPX为底物的LB琼脂平板上一式两份地筛选转化子来鉴定β-木糖苷酶基因。商业化生产用作甲醇生产酶的β-木糖苷酶可以帮助克服燃料短缺。