Rhodopseudanonas Palustris And Bacillus Subtilis Combined To Repair Field Soil Cadmium Pollution

This research used the potted plant approach,BCR four footwork,flame atomic absorption method,and the method of dilution coated tablet were used to determine the cadmium content in the soil,the number of microbial populations,soil urease,soil catalase,soil invertase,soil alkaline phosphatase activity and physiological and biochemical indicators,cadmium content in rhizomes of Chinese cabbage,in order to study the effect and safety of the combined use of Rhodopseudanonas palustris and Bacillus subtilis on remediation of heavy metal cadmium contamination in farmland soil for potted Chinese cabbage for remediation of cadmium pollution in farmland soil in order to explore its effectiveness and to provide theoretical basis for application of the new type bio-bacterial manure.The experimental results showed that:The first,the results showed that either Rhodopseudanonas palustris or Bacillus subtilis alone,or their combination could enhance the fixation of the metal in soil,i.e.to change cadmium from soluble state to insoluble state,thus decrease its bioavailability.There was a significant difference in the number of soil microorganisms(P<0.05),and the amount of bacteria reached105 CFU/g.The second,Adding medium and high concentrations of Bacillus subtilis and high concentration combined bacteria significantly increased soil urease,catalase,and alkaline phosphatase activities(P<0.05).Among them,soil urease increased by 89.37%,104.37% and 226.87% respectively;soil catalase increased by 65.72%,85.81% and 402.18% respectively;soil alkaline phosphatase increased by 497.82%,202.17% and 376.08%respectively;There was no significant change in invertase activity(P>0.05).Overall,the inoculation promoted soil enzyme activity and improved soil fertility.The third,the addition of Rhodopseudanonas palustris or Bacillus subtilis alone,or their combination effects significantly reduced(P<0.05)thecadmium content in the root and stem of Chinese cabbage.The combination treatment group had the highest repairing effect with the biomass of Chinese cabbage increased by 18.13-69.55%.The removal rates of cadmium in root and stem reached 58.06-71.37% and 73.66-76.70% respectively,and could reduce bioavailability of cadmium in soil by 32.7%.The results of this study demonstrated that Rhodopseudanona spalustris and Bacillus subtilis had a strong ability to remove cadmium from contaminated soil,and could significantly promote the growth of Chinese cabbage.It also showed that the combination of the two bacteria was a feasible and promising approach.