Researches And Application Of Bioassay Methods

The development of science and technology has enabled people to synthesize more and more compounds, as a result, environment as the receiver of industrial and living wastes was sufferring from contamination greatly. The traditional method for environmental monitor was chemical analyse, by means of which the types and the concentration of pollutants could be detected quickly and sensitively. However, it wasted a lot of time and effort when we detected large pollutants one by one by this method; Besides, we couldn't get the comprehensive effect of many pollutants. In view of this, bioassay comed with the tide of fashion, especially the recombinant receptor gene/reporter gene yeast assay based on the new hormone-receptor communicated theory. The recombinant yeast assay is popular because of its simple, quickness, sensitiveness, and aptness to bulk screening and detection, what is more, the yeast test system is similar to the mechanism of mammal's endocrine system. In this paper, the endocrine disruptive effect of the sewage sludge in Beijing and some substituted phenols were tested using the recombinant gene yeast assay, meanwhile, the aromatic effect of the sewage sludge in Beijing was obtained using the vitro H4IIE assay. The application of the two assays validated the superiority of the recombinant gene yeast assay and the necessity of building two-hybrid yeast recombinating aromatic receptor gene. The main results were summarized as follows.1 In the bioassay for the sewage sludge, results showed that both androgenic and progestogenic activity couldn't be found, estrogenic activity was at a low level; but there were the obviously inhibitory effect for androgen receptor and progestogen receptor, as well as the strong aromatic effect. The composting process played a little part in removing endocrine disruptors and aromatic compounds efficiently.2 In the recombinant gene yeast assay for phenols, results revealed that the inducible/inhibitory effect for estrogenic receptor was related to the substituent structure on phenolic ring. All of the structure characters contribute to exhibit estrogenic activity, which included alkyl group in the para-position, the substituent impelling electron withdrawal on the alkylphenol ring and the structure symmetry; However, some features tended to decrease the estrogenic activity, which included alkyl group in the ortho-position,nitro-substitution in the ortho-position,multiple hydroxyl groups on a single ring and amidogen substituent on benzene ring. The key characteristic properties for inhibiting E2-inducing-β-Galactosidase activity are associated with the substitution of at least three nonhydrogen atoms (excluding three-carbon alkyl group) on a monohydroxy phenolic ring.3 In this study Ahr LBD gene has been cloned successfully and joined to yeast expression vector PGBKT7 orientationally to build bait plasmid PGBKT7-Ahr using gene cloning and yeast two-hybrid assay; the prey plasmid PGAD424-GRIP1 was extracted and separated, with the following identification by sequencing.