摘要
从内蒙古呼伦贝尔草原的盐碱湖中分离到的一株低度嗜盐嗜碱细菌Bacillus sp F26，能积累高水平过氧化氢酶（CAT）。对Bacillus sp F26发酵产过氧化氢酶的环境与营养条件的研究结果表明，其积累高水平过氧化氢酶的适宜环境条件为：温度37℃，种龄20-22h，接种量5％，装液量50mL／（250mL的摇瓶）。适宜发酵培养基组成（g／L）为：葡萄糖15，牛肉膏10，玉米浆10，酵母膏5，磷酸二氢钾1，氯化镁0．2，氯化钠50，碳酸钠10。采用上述条件进行摇瓶分批发酵实验，发酵20h，过氧化氢酶酶活达到16．32U／mL，细胞干重为4．12g／L。进一步研究发现，在对数生长后期（16h）添加2mmol／L的H2O2可以明显刺激产酶，在5L的发酵罐上进一步以指数速率方式流加H2O2，由于该流加方式可降低H2O2对细胞的毒害作用，过氧化氢酶酶活达到29．89U／mL，与分批发酵相比提高了92．8％。
The effects of culture conditions and medium compositions on the fermentative production of catalase （CAT） by a slight halophilic and alkaliphilic bacterium Bacillus sp F26, isolated from Haoji Soda Lake, P. R China, were investigated. The optimal culture conditions were obtained as following, temperature 37 ℃, age seed 20-22 h , inoculum size 5% and volume 50 mL in 250 mL shaking-flask. The optimal fermentation medium contained 15 g/L of glucose, 10 g/L of beef extract, 10 g/L of corn liquid, 5 g/L of yeast extract, 1 g/L of KH2PO4, 0. 2 g/L of MgCl2, 50 g/L of NaCl and 10 g/L of Na2CO3. High CAT activity （16.32 U/mL） and dry cell weight （4. 12 g/L） were observed at 20 h in shaking-flask culture. It was also found that addition of H2O2（2 mmoL/L in the medium） at later exponential phase greatly induced the synthesis of CAT. The maximum CAT activity （29.89 U/mL） was obtained by using exponential H2O2 feeding strategy in 5 L fermentor, which was 92.8% higher than that in batch fermentation.
出处
《食品与生物技术学报》
CAS
CSCD
北大核心
2007年第1期77-83,共7页
Journal of Food Science and Biotechnology
基金
国家自然科学基金资助项目(20676056)
国家高技术研究发展计划(863)资助项目(No.2003AA322050)
江苏省创新人才(学术)基金资助项目(BK2004401)
