摘要
以沙雷氏菌JXJ-7为供试菌株,采用单因素试验确定了其最适发酵培养基配方、最佳胞外产酶条件,并对其粗酶酶学性质进行了研究。结果表明:该菌株的最佳发酵培养基为葡萄糖3.750 g/L、牛肉浸膏8.75 g/L、K2HPO4 2 g/L、菜籽油乳化液体积分数1.75%,初始pH值9;最佳发酵条件为培养温度30℃、装样量20 mL/250 mL、接种量1.0%、发酵时间28 h;沙雷氏菌JXJ-7所产胞外脂肪酶粗酶最适底物为对硝基苯酚辛酸脂,在10～35℃的温度范围内具有较高的酶活力,其中35℃时酶活力最高,但热稳定性较差;该酶具有良好的酸碱耐受性,pH值为9.5～10.5时酶活力较高;酶样品受到供试金属离子的抑制,在供试有机溶剂中具有良好的耐受性,对供试表面活性剂有一定的耐受性。总之,JXJ-7脂肪酶为低温碱性脂肪酶,在低温碱性环境的工业领域中有一定的应用潜力。
Using Serratia JXJ-7 as the test strain,the optimum fermentation medium formulation and the optimum conditions for extracellular enzyme production were determined by single factor test,and the crude enzymatic properties of Serratia JXJ-7 were studied.The results showed that the optimum fermentation medium was glucose 3.750 g/L,beef extract 8.75 g/L,K2HPO4 2 g/L,and rapeseed oil emulsion 1.75%at an initial pH 9.The optimum fermentation conditions were incubation temperature 30℃,sample loading 20 mL/250 mL,inoculum concentration 1.0%and fermentation time 28 hours.Serratia JXJ-7 produced crude extracellular lipase and the optimum substrate was p-nitrophenol octanoic acid lipid.The enzyme activity was higher in the temperature range of 10 to 35℃,and the highest was at 35℃,but the thermal stability was poor.It had good acid-base tolerance and high enzyme activity when pH value was 9.5-10.5.Enzyme samples were inhibited by metal ions,well tolerated in organic solvents,and a certain tolerance to the tested surfactants.In conclusion,JXJ-7 lipase is a low-temperature alkaline lipase,which has a certain application potential in the industrial field of low-temperature alkaline environment.
作者
陈芳
石红璆
查代明
余甜甜
张炳火
李汉全
CHEN Fang;SHI Hong-qiu;ZHA Dai-ming;YU Tian-tian;ZHANG Bing-huo;LI Han-quan(School of Pharmacy and Life Sciences,Jiujiang University,Jiujiang 332000,PRC)
出处
《湖南农业科学》
2018年第11期1-6,9,共7页
Hunan Agricultural Sciences
基金
九江学院校级科研项目(8500350)
关键词
沙雷氏菌属
培养基
发酵条件
酶学性质
低温碱性脂肪酶
Serratia
culture medium
fermentation conditions
enzymatic properties
low temperature alkaline lipase
