添加巨大芽孢杆菌与胶质芽孢杆菌对土壤DTPA提取态Cd的影响

Effect of Bacillus megateriumand Bacillus mucilaginosus on Soil DTPA Extractable Cd

采用短期和长期恒温培养的方法,研究巨大芽孢杆菌、胶质芽孢杆菌及两菌混合液对土壤DTPA提取态Cd的影响。结果表明,短期试验中巨大芽孢杆菌对土壤Cd有一定的活化作用,不同Cd污染水平条件下,巨大芽孢杆菌使土壤DTPA提取态Cd增加比例在3.8%～24.4%之间,其中50mg/kg CdCO3污染水平条件下,巨大芽孢杆菌加菌量为2ml时活化效果最好,而胶质芽孢杆菌和混合菌则对土壤Cd无显著影响或有一定的钝化作用。长期培养试验中,巨大芽孢杆菌也表现出了对土壤Cd的活化作用,未添加Cd条件下,巨大芽孢杆菌加菌量为10,20ml时,土壤DTPA提取态Cd较对照分别增加了44.0%,28.9%,而胶质芽孢杆菌和混合菌对土壤Cd无显著影响或有一定的钝化作用。

In order to investigate the impact of Bacillus megaterium, Bacillus rnucilaginosus and the mixture of both bacteria on soil DTPA extractable Cd, short-term and long-term incubation experiments were carried out. The results on short-term test showed that soil Cd was activated after adding Bacillus megateriurn to soil, soil DTPA extractable Cd increased by 3.8%-24.4% under different Cd pollution levels. Under 50 mg/kg CdCO3 level, soil Cd achieved maximum activation effect which adding 2 ml Bacillus megaterium to soil, but both Bacillus rnucilaginosus and the mixture bacteria had no significant impact on soil Cd or even passivation. Results on long-term test showed that Bacillus rnegateriurn also activated soil Cd under the original Cd polluted level, the soil DTPA extractable Cd increased by 44. 0% and 28. 9% respectively compared with the control after adding 10 ml and 20 ml Bacillus megaterium to soil, while both Bacillus mucilaginosus and the mixture bacteria had no significant impact on soil Cd or even passivation, which was similar to those obtained in short-term test.