摘要
在优化1株粘质沙雷氏菌发酵产过氧化氢酶(CAT)的培养基成分时发现,柠檬酸可以显著提高该菌胞内CAT的活力。结合先前报道,探究了柠檬酸促进粘质沙雷氏菌合成胞内CAT的原因。以等摩尔碳含量的柠檬酸、葡萄糖、柠檬酸与葡萄糖的混合物分别作为碳源,测定了在不同碳源发酵产CAT时粘质沙雷氏菌胞内抗氧化的相关数据。结果显示:添加柠檬酸(20g/L)后,该菌细胞内H_2O_2和羟自由基含量均比对照组(葡萄糖)高,说明柠檬酸代谢物对其产生了活性氧胁迫,进而诱导更多CAT的合成。考察了甲萘醌和百草枯(活性氧O^(2-)·的来源物)对该菌合成CAT的影响,实验结果验证了适量的活性氧能够诱导该菌合成CAT的结论。
In an experiment to optimize the culture conditions for the catalase（CAT） production by Serratia marcescens SYBCT02,an interesting phenomenon occurred that the addition of ctric acid to the culture medium significantly stimulated the accumulation of CAT.To explore the reason for this finding,an experiment was designed based on the previous reports.Three kinds of carbon source,i.e.glucose,ctric acid and a mixture constituted by glucose and citric acid,with the same amount of carbon element,were used in the culture medium for CAT production by Serratia marcescens SYBCT02.After determining the contents of cellular antioxidant substrates and the activities of cellular antioxidant enzymes,an occurrence of oxidative stress was found in the cells of Serratia marcescens SYBCT02 cultivated in the media with citric acid.Compared with the control,the increased amounts of hydrogen peroxide（H2O2） and hydroxyl radical（ ·OH ） induced the synthesis of CAT after an addition of citric acid to the culture medium. This conclusion was further confirmed by the addition of exogenous reactive oxygen（produced by menadione and paraquat） to the culture media.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2011年第11期1-5,共5页
Food and Fermentation Industries
基金
国家863计划项目(No.2010AA101501)
