Study On The Degradation Of Steroid Compounds By Engineering Bacteria

In this study, the experimental materials contained three drinking water and 27 environmental water samples from different regions in China. It makes a detection of five major steroid hormones (Estrone, Estradiol, Estriol, Cholesterol, Testosterone) with high performance liquid chromatography (HPLC) method combining with solid phase extraction (SPE). At the same time, it continued to detect the content of major steroid substances in water form four different water sampling sites along the Minjiang River in the section of Fuzhou and its inflows. Comamonas testosteroni has the ability of degradation to a variety of refractory compounds and of digestion steroid compounds as sole carbon and energy.This study uesed Comamonas testosteroni and its genetically engineered bacteria (P8, Ca3) to degradate the steroid hormones in polluted water Engineering bacteria have a high practical value in bioremediation,and it provides a theoretical basis for bioremediation of environmental pollution.The main results were as follows:1. The HPLC-SPE was used to detect steroids (Estrone, Estradiol, Estriol, Cholesterol, Testosterone) in water sumples from different sits. The results showed that:27 water samples collected from different regions in China contained residues of the steroids (estrone, estradiol, estriol, testosterone, cholesterol) and the content of the steroids are significantly different. At the same time, The steroid matters were not detected in such 3 drinking water samples:commercial pure water, mineral water and.2. This study detected the concentration trends of steroidal(Estrone, Estradiol, Estriol, Testosterone) in different seasons during a year. The water sumples were collected from four sits along the Minjiang River in the section of Fuzhou and its inflows. The results showed that:the content trends of the above steroid were exactly inconsistent. Estradiol,the most potential impact on the environment, was relatively higher in January and November and relatively lower in May and August. The variance analysis of steroidal content(estrone、17-beta-Estradiol、Estriol、Testosterone) in different seasons (months) showed the content of the steroid matters were significantly different. The content of main ingredient substances of steroids in total were the lowest in May. The content variance analysis of steroidal showed it was significant differences with other three months.3. This study uesed wild-type Comamonas testosteroni and engineered bacteria (P8, Ca3) to degradate the steroid hormones (estrone, estradiol, estriol, testosterone) in polluted water. The results showed that the degradation rate of steroid was significant difference at the level of each factor:water types, strains, seasons. The ability of genetically modified strains P8 and Ca3 to degradate steroids was better than the wild type strain Ct. The degradation rate of genetically modified strains P8 is 1.13 to 1.33 times higher than the wild type strain Ct. It can reach 68.32%～ 70.22%. But the ability of adaptation of wild-type strain Ct. was higher than that of genetically modified strains P8, Ca3. in environmental water.The population density of strains showed exponential decay in the whole degradation process. After the 60 h, the number of live cells remaining three strains is that Ct> P8> Ca3.