College of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China.
Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
Environ Sci Pollut Res Int. 2020 Oct;27(30):37668-37676. doi: 10.1007/s11356-020-09846-2. Epub 2020 Jun 30.
The principal objective of this study was to investigate the strengthened remediation effect and relevant mechanism of P. aeruginosa on ryegrass (Lolium multiflorum Lam.) for soil contaminated by Cu-Pb-Cd compound heavy metals. The results showed that the complex heavy metals' contamination had remarkable inhibiting effect on the growth of plants (P < 0.01), and the biomass of ryegrass's stem and leaves declined by 28.2%, while that of roots decreased by 34.7% after 45 days. The inoculation of P. aeruginosa promoted the growth of ryegrass in polluted soil, in which the biomass recovered to the same level of that in normal plant; the activity of both catalase and urease in the soil also increased strikingly (by 29.3% and 75.7%, respectively); the ratio of residual heavy metals in the soil decreased, while the acid extractable heavy metals increased notably. Therefore, the absorption and accumulation of ryegrass to the heavy metals in soil were improved to some extent; the bioconcentration factor of Cu, Pb, and Cd in ryegrass increased by 35.9%, 55.6%, and 283.5%, respectively. The exterior microorganism allowed the accumulation of Cu, Pb, and Cd in shoots of ryegrass increasing remarkably, while in roots, only the accumulation of Pb increased by 16.3%, and that of both Cu and Cd decreased. Besides, in the P. aeruginosa-inoculated system, the transfer factor of Cu and Cd in plants increased strikingly, while that of Pb decreased.
本研究的主要目的是研究铜-铅-镉复合重金属污染土壤中铜绿假单胞菌对黑麦草（Lolium multiflorum Lam.）的强化修复效果及相关机制。结果表明，复合重金属污染对植物生长有显著抑制作用（P < 0.01），45 d后黑麦草茎和叶的生物量下降了 28.2%，而根的生物量下降了 34.7%。铜绿假单胞菌的接种促进了污染土壤中黑麦草的生长，使生物量恢复到正常植物水平；土壤中过氧化氢酶和脲酶的活性也显著增加（分别增加了 29.3%和 75.7%）；土壤中残留重金属的比例降低，而酸可提取的重金属明显增加。因此，黑麦草对土壤中重金属的吸收和积累在一定程度上有所提高；黑麦草对 Cu、Pb 和 Cd 的生物浓缩系数分别增加了 35.9%、55.6%和 283.5%。外生微生物使黑麦草地上部对 Cu、Pb 和 Cd 的积累显著增加，而根部仅使 Pb 的积累增加了 16.3%，Cu 和 Cd 的积累则减少。此外，在铜绿假单胞菌接种系统中，植物体内 Cu 和 Cd 的转移因子显著增加，而 Pb 的转移因子则减少。
