睾丸酮丛生假单胞杆菌甾醇降解酶活力研究
发布时间：2018-10-15 18:57
【摘要】：目前,冠心病日益严重地威胁着人类的健康和生命,在欧美等发达国家冠心病死亡已超过所有癌症死亡的总和,占总死亡率的27.4%。如果再加上脑中风的死亡率,则以动脉粥样硬化为基础病变导致的死亡率更高。产生这些疾病的主要因素就是人体内甾醇含量的严重超标,所以必需限制食用甾醇含量高的食物。本研究利用睾丸酮丛生假单胞杆菌(菌株c.test+act5、菌株c.test+tac、菌株c.test)具有消化甾醇这一特性,以胆固醇为底物筛选其降解甾醇的培养条件,使胆固醇降解酶的活力相对提高,以期为高效降解甾醇类物质的工程菌的筛选奠定基础。主要研究结果如下: 1、通过对影响胆固醇降解的诱导时间、培养基pH值、诱导温度、装液量等因素的研究后,发现诱导时间、培养基pH值、诱导温度对三种菌株胆固醇降解酶的活力影响较大,装液量也有一定的影响。由此筛选出最佳诱导时间14小时、培养基最佳pH7.0、最佳诱导温度30℃、及最佳装液量50ml于250ml摇瓶中。根据上述筛选好的培养条件用平板稀释法测定三个稀释度下10~(-7)、10~(-8)、10~(-9)三个菌株的活菌数,同一培养条件下每毫升菌液中菌株c.test+act5中的活菌数最高达1.275×10~8个,菌株c.test+act中的活菌数达0.824×10~8个,菌株c.test中的活菌数最少为0.300×10~8个。 2、本研究同时对睾丸酮丛生假单胞杆菌三个菌株降解胆固醇的发酵培养基组分进行筛选。结果表明,不同原料对发酵液中胆固醇降解酶活力影响相差较大,本研究以有机质(酵母膏、蛋白胨、葡萄糖、吐温)和无机盐(NaCl、K_2HPO_4、MgSO_4、FeSO_4)分别设计L_(18)(3~7)和L_9(3~4)正交试验,通过比较胆固醇降解酶活力的大小获得有机质的最佳配方分别为:5g/L酵母膏、10g/L蛋白胨、5g/L葡萄糖粉、0.5ml/L吐温。
[Abstract]:At present, coronary heart disease is threatening human health and life day by day. In developed countries, such as Europe and America, the death rate of coronary heart disease has exceeded the sum of all cancer deaths, accounting for 27.444% of the total death rate. If combined with stroke mortality, atherosclerotic disease causes higher mortality. The main cause of these diseases is the severe excess of sterols in the human body, so it is necessary to limit the consumption of foods with high levels of sterols. In this study, we used the characteristic of c.test act5, c.test tac, (c.test) to digest sterol, and used cholesterol as substrate to screen the culture conditions of sterol degradation, so that the activity of cholesterol degrading enzyme was improved. In order to lay a foundation for the screening of engineering bacteria that can efficiently degrade sterols. The main results are as follows: 1. The induction time was found through the study of the factors influencing the degradation of cholesterol, such as the induction time, the pH value of the medium, the induction temperature, the amount of liquid, and so on. The pH value of culture medium and induction temperature had great influence on the activity of cholesterol degrading enzyme of the three strains, and the amount of liquid was also affected to some extent. The optimum induction time was 14 hours, the optimal induction temperature of pH7.0, was 30 鈩，
本文编号：2273516
[Abstract]:At present, coronary heart disease is threatening human health and life day by day. In developed countries, such as Europe and America, the death rate of coronary heart disease has exceeded the sum of all cancer deaths, accounting for 27.444% of the total death rate. If combined with stroke mortality, atherosclerotic disease causes higher mortality. The main cause of these diseases is the severe excess of sterols in the human body, so it is necessary to limit the consumption of foods with high levels of sterols. In this study, we used the characteristic of c.test act5, c.test tac, (c.test) to digest sterol, and used cholesterol as substrate to screen the culture conditions of sterol degradation, so that the activity of cholesterol degrading enzyme was improved. In order to lay a foundation for the screening of engineering bacteria that can efficiently degrade sterols. The main results are as follows: 1. The induction time was found through the study of the factors influencing the degradation of cholesterol, such as the induction time, the pH value of the medium, the induction temperature, the amount of liquid, and so on. The pH value of culture medium and induction temperature had great influence on the activity of cholesterol degrading enzyme of the three strains, and the amount of liquid was also affected to some extent. The optimum induction time was 14 hours, the optimal induction temperature of pH7.0, was 30 鈩，
本文编号：2273516
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