海洋类固醇降解菌初步研究生物化学与分子生物学专业论文.docxVIP

汕头 汕头大学硕士学位论文 PAGE PAGE VI Abstract Environmental hormone is a type of chemical substances existing in the environment, which have the same chemical structure and hormone activity when access to people and animals. Once these compounds enter human body through the digestive system and respiratory system, it will influences the synthesis, transportation, release, and metabolism of hormone, disrupts and causes functions obstacles of the endocrine system, and the reproductive system and the nervous system of human body. As one kind of environmental hormone, steroids and its derivatives was let out with animal manure and factory sewage. Exceed standard level of estrogen have been detected in coastal waters, which means marine environmental has been polluted by steroids. Take the advantages of microorganisms in environment pollutant degradation and removing, this study was set out to explore the possibility and feasibility of steroid microbial degradation in marine. The results are as followed: 39 strains of steroid-degrading bacteria were isolated from Shantou Port and the Nanao Island marine culture zones. Most bacterial strains can degrade 3-4 kinds of substrates, X and Y3 can degrade all of the substrate used in the experiment, the strain N8 and Y18 can only degrade estradiol, N9 and N12 can only degrade cholesterol and Y12 can only degrade 17β-ethinyl estradiol. From the neighbor-joining tree N1, N3 and N6 are belong to Vibrio, and strains C and Y2 were P. ganghwense and A. venetianus respectively. Bacteria culture concentration, total protein, the degradation rate and the different of protein expression were used in studying the ability of testosterone degradation of testosterone-degrading bacteria N1, N3, N6 and N13. In addition to good at testosterone degradation, bacterium Vibrio sp.N3 could also use 17β-estradiol (E2), 17β-ethinyl estradiol (EE2), estriol (E3), and cholesterol as the sole carbon source. (1) In order to enhance its capability of testosterone