中文摘要：

为丰富产耐热β-淀粉酶菌种资源，从土样中筛选得到高产淀粉酶菌株B10-54，鉴定为枯草芽孢杆菌（Bacillus subtilis）。经硫酸铵沉淀、阴离子交换柱分离纯化获得β-淀粉酶，测定其最适作用温度为65 ℃，最适pH为6.0，Ni2＋、Mg2＋离子对其酶活有促进作用。对B10-54发酵产β-淀粉酶进行优化，确定最适培养基碳氮源为木薯粉2%、豆粕粉4%，最适发酵条件为初始pH 7.0、温度37 ℃、转速190 r/min、接种量4%，摇床培养64 h后酶活力可达6 724 U/mL，比优化前提高了3.06倍。在装液量为2.5 L的5 L发酵罐中发酵，转速350 r/min，通气量1 L L-1 min-1，控制pH在6.5-7.5之间，发酵48 h后酶活可达最高酶活6 920 U/mL，比摇瓶培养缩短了发酵时间。因此菌株B10-54产耐热β-淀粉酶并可利用廉价原料木薯、豆粕粉发酵，可大大降低生产成本。图7 表4 参22

英文摘要：

A high-yield amylase strain B10-54 was isolated from the soil in order to enrich the resources of β-amylase producing strains. The strain B10-54 was identified as a species of Bacillus subtilis by traditional physiological experimental method and 16S rRNA analysis. The single-factor and orthogonal experiments were performed to determine the optimal conditions for enzymatic production. The target enzyme β-amylase was purified by ammonium sulfate precipitation and Q Fast Flow-sepharose ion-exchanger chromatography. The temperature optima of the purified β-amylase was 65 ℃ and the optimum pH was 6.0. The β-amylase activity could be obviously stimulated by Ni2＋, Mg2＋. The optimal carbon source and nitrogen source were 2% cassava flour and 4% soybean dreg. The fermentation conditions were initial pH7.0, fermentation temperature 37 ℃, rotation speed 190 r/min with 4% inoculation volume. After 64 h fermentation, the enzyme activity was as high as 6 724 U/mL, 3.06 times higher than before. The conditions of B10-54 in 5 L fermentor were liquid volume 2.5 L/5 L, 1 L L-1 min-1, stirring speed 350 r/min, pH controlled between 6.5-7.5. The enzyme activity was 6 920 U/mL after only 48 h, a much shorter growth time than before. B10-54 strain produces thermostable β-amylase from cheap material such as cassava and soybean dreg to reduce production cost, therefore should be further studied. Fig 7, Tab 4, Ref 22