摘要
目的:优化菌株Bacillus cereus SG03在10L发酵罐中产胆固醇氧化酶的工艺条件,为该菌株的进一步应用提供依据。方法:在10L发酵罐中,通过单因素实验,分别考察了培养液起始pH、搅拌速率、溶解氧(DO)浓度对Bacillus cereus SG03产胞外胆固醇氧化酶的影响。结果:较佳的发酵条件为培养液起始pH6.8、搅拌速率250r/min、溶解氧(DO)浓度80%。在此基础上,对发酵过程进行了两阶段DO控制,发酵前20h DO控制在90%,然后调整为20%,直至发酵结束。较单一DO控制,最大胞外胆固醇氧化酶产量、生产效率分别提高了30.2%和20.0%,达到了1.38U/mL和0.03U/(mL·h)。
Objective：The technique of producing cholesterol oxidase by the strain of Bacillus cereus SG03 in a IOL fermenter was optimized,in order to provide the basis for further application of the strain.Methods.The effect of pH of the culture medium,stirring rate and DO on the production of cholesterol oxidase in the broth by Bacil/us cereus SG03 was studied in a IOL fermentor. Results：The optimum fermentation conditions were initial pH at 6.8, stirring rate at 250r/min and DO at 80%.Based on the results, a strategy of two stage DO manipulation was proposed, controlling DO at 90% before the 20h and at 20% from the 20h to at the end during the fermentation.The maximum COD activity in the broth and production efficiency reached 1.38U/mL and 0.03U/（ mL. h）, respectively improved 30.2% and 20.0% higher than with one stage manipulation.
出处
《食品工业科技》
CAS
CSCD
北大核心
2014年第17期137-140,146,共5页
Science and Technology of Food Industry
基金
安徽省高等学校优秀青年人才基金项目(2011SQRL079)
安徽省高等学校省级自然科学研究重点项目(KJ2013A049)
