耐热β-淀粉酶高产菌株的筛选及其产酶条件优化  

Screening and Fermentation Optimization for a High-yield Thermostableβ-Amylase Producing Strain

作　　者：邹艳玲[1] 徐美娟[1] 饶志明[1] 

机构地区：[1]江南大学生物工程学院工业生物技术教育部重点实验室,无锡214122

出　　处：《应用与环境生物学报》2013年第5期845-850,共6页Chinese Journal of Applied and Environmental Biology

基　　金：教育部新世纪优秀人才计划项目(NCET-10-0459);国家重点基础研究发展计划("973"计划)项目(2012CB725202);国家高技术研究发展计划("863"计划)项目(2011AA02A211);国家自然科学基金项目(21276110;30970056);高等学校博士学科点专项科研基金项目(20110093120001);中央高校基本科研业务费专项资金项目(JUSRP31001);江苏高校优势学科建设工程项目资助~~

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-1min-1,控制pH在6.5-7.5之间,发酵48h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.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

关 键 词：枯草芽孢杆菌 Β-淀粉酶 耐热酶 菌种筛选 发酵条件优化 

分 类 号：TQ925[轻工技术与工程—发酵工程] Q936[生物学—微生物学]