| Heavy metal pollution has become a serious environmental problem of the global.It is not only harmful to the ecological environment,but also to human health through the food chain.This study was aim to screen of bacteria and fungi resistant to high concentrations of Pb,Cd from the Pb,Cd-contaminated soil by the dilution plate,and to determin effects of bacteria and fungi on the removal of heavy metals through liquid culture,and then selected two strains for pot experiment,in order to study the restoration effects on heavy metal contamination soil.The main results are as follows:1.22 microorganisms resistant to Pb,Cd were screened from the Pb,Cd contaminated soil.No.1 to No.10 strains were fungi,and No.11 to No.22 were bacteria.The concentration of fungi and bacteria resistant to heavy metal Pb was up to 1500 and 500 mg·kg-1, respectively.The concentration of them resistant to heavy metal Cd was up to 600 and 700 mg·kg-1,respectively.And the concentration of them resistant to heavy metals Pb,Cd combined pollution was up to 1200 and 600 mg·kg-1.The 22 strains had removal effect of Pb, Cd in liquid culture medium,the removal rate of 1ts,2ts,6ts to Pb was over 60%,and the content of the bacteria in vivo is 22.52,7.39,0.4 mg·kg-1,respectively.What's more,the removal rate of 1st(resistant to Pb pollution) was as high as 72.45%,the removal rate of 9ts (resistant Pb and Cd combined pollution) to Pb,Cd reached 54.82%and 20.86%, respectively.The content of hyphal body reached 18.46 and 0.206 mg·kg-1,respetively.In orde to compare the removal effect of a single strain and combined strain to heavy metal pollution,we selected 1th and 9th strain for certification.By morphology observation and sequence of DNA,1th strain was Cephalosporium chrysogenum and 9th strain was Cephalosporium.2.Pot trial showed that two species strains can significantly promote the growth of Chinese cabbage,and the growth of Chinese cabbage was better in sterilization than un-sterilization treatment.The growth of Chinese cabbage was the best in sterilized treatment with inoculated 10mL of 1st strain,and the cumulative content of Pb,Cd in Chinese cabbage plants was only 0.142μg/plant/(DW)and 0.117μg/plant/(DW),respectively,which was only half of the control.3.Pot trial showed that the two strains can promote Pb,Cd from into low bioavailability, and the effect was the best in seedling stage,when the bioavailability of heavy metals Pb,Cd was lowest.In the seedling stage(19d),the content of the exchangeable Pb,Cd have decreased in sterilized soil or in un-sterilization soil,the content of iron-manganese oxide bound and residual was no significant difference,but the content of the organic integration increased significantly.And the conversion rate of Pb,Cd reached 83.54%,78.04% respectively in inoculating 10mL No.1 strains with sterilization treatment.Inoculated 1th and 9th strains can effectively reduce the heavy metals Pb,Cd toxicity in the soil,and decline the absorption of crops to heavy metals,which were helpful to crop growth.
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