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DDT (1,1,1-trichloro-2 ,2-bis (p-chlorophenyl) ethane, DDT), is one of the world's first released by the United Nations Environment Programme priority treatment of 12 persistent organic pollutants in environmental residue the congener mainly include p, p'-DDT, o, p'-DDT, p, p'-DDE, o, p'-DDE, p, p'-DDD and o, p'-DDD, collectively referred DDTs . DDTs stable physical and chemical properties, difficult natural degradation, easy carcinogenic, teratogenic and organisms in the bio-accumulate, mutagenic, such as the role of the DDTs environmental cleanup technology is of great significance to ensure that human health and the sustainable development of society . In this thesis, diphenyl methane as the sole carbon source of energy substances obtained an efficient DDTs degrading bacteria from Dagu River sediment screening and identification of molecular biology and morphological observation, the strain was identified as Alcaligenes (Alcaligenes sp.), named DG-5, its 16S rDNA the GeneBank sequences have been included, the accession number FJ919599. Further DDTs substrate degradation characteristics of the strains of DDTs and compared with other strains of the laboratory results are as follows: (1) Alcaligenes sp.DG-5 concentrations were 0.5 mg / L, 5mg / L, 15 mg / L of DDTs mixtures 336h degradation rate, respectively, 94%, 77% and 51%, respectively. Plus co-metabolism substrates can effectively promote the degradation of the liquid phase of DDTs, promoting effect descending order of yeast extract> tryptone> β-cyclodextrin. Inoculum size will affect the degradation efficiency of DDTs, with bacterial concentration of the increase, along with increased the DDTs degradation rate. Formate to eliminate the the DDTs degradation process of NADPH lack inhibition, add a low concentration of formate can effectively improve the degradation efficiency of DDTs, the high concentration of degradation is caused by inhibition. Not found priority Alcaligeties sp.DG-5 for a DDT or its congeners selective. (2) DDTs degrading strain DG-5, DG-6, DG-M under aerobic conditions effectively degrade a variety of organic chlorine pesticides as well Aroclor1242 of that biodegradable organic chlorinated pollutants have some versatility. PAH degradation strains JH-M has a strong ability to degrade for a variety of chlorobenzoate. (3) Alcaligenes sp.DG-5 for the water content rate of 20%, 50%, 200% of the soil system the DDTs degradation rate of 1%, 5%, 2%, respectively, does not exhibit a good degradation effect. The DDTs molecules adsorbed to soil particles is difficult to activated carbon felt desorption. The above results show that under aerobic conditions, Alcaligenes sp.DG-5 can be quickly and effectively degrade DDT and its congeners, the degradation of other organic chlorinated pollutants also has a certain versatility bad environment, which is further applied DDTs point pollution bioaugmentation repair efficiency basis.
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