Hong Youwei, Liao Dan, Chen Jinsheng, Khan Sardar, Su Jianqiang, Li Hu
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen, 361021, China,
Environ Sci Pollut Res Int. 2015 May;22(9):7071-81. doi: 10.1007/s11356-014-3912-6. Epub 2014 Dec 11.
These pot experiments aimed to investigate the effects of polycyclic aromatic hydrocarbons (PAHs) on plant uptake, rhizophere, endophytic bacteria, and phytoremediation potentials of contaminated sediments. Salt marsh plant Spartina alterniflora was selected and cultivated in phenanthrene (PHE)- and pyrene (PYR)-contaminated sediments (for 70 days). The results indicated that the amount of PHE removed from the sediments ranged from 13 to 36 %, while PYR ranged from 11 to 30 %. In rhizophere sediment, dehydrogenase activities were significantly (P < 0.05) enhanced by higher concentration of PHE treatments, while polyphenol oxidase activities were prohibited more than 10 % in non-rhizophere sediment. Compared with the control, PHE treatments had also significantly (P < 0.05) lower total microbial biomass; especially for gram-negative bacteria, this decrease was more than 24 %. However, the PYR treatments had little effect on the dehydrogenase, polyphenol oxidase, and total phospholipid fatty acid analysis (PLFA) biomass. The greatest abundance of PAH-ring hydroxylating dioxygenases isolated from gram-negative bacteria (PAH-RHDα-GN) of rhizoplane and endophyte in roots were found at high concentration of PHE treatments and increased by more than 100- and 3-fold, respectively. These results suggested that PAH pollution would result in the comprehensive effect on S. alterniflora, whose endophytic bacteria might play important roles in the phytoremediation potential of PAH-contaminated sediments.
这些盆栽实验旨在研究多环芳烃（PAHs）对植物吸收、根际、内生细菌以及污染沉积物植物修复潜力的影响。选择盐沼植物互花米草，在菲（PHE）和芘（PYR）污染的沉积物中培养70天。结果表明，沉积物中去除的菲量在13%至36%之间，而芘在11%至30%之间。在根际沉积物中，较高浓度的菲处理显著（P < 0.05）提高了脱氢酶活性，而非根际沉积物中多酚氧化酶活性被抑制超过10%。与对照相比，菲处理的总微生物生物量也显著（P < 0.05）降低；特别是革兰氏阴性菌，减少超过24%。然而，芘处理对脱氢酶、多酚氧化酶和总磷脂脂肪酸分析（PLFA）生物量影响较小。在高浓度菲处理下，从根际平面和根部内生菌的革兰氏阴性菌中分离出的PAH环羟基化双加氧酶（PAH-RHDα-GN）丰度最高，分别增加了100倍以上和3倍。这些结果表明，PAH污染会对互花米草产生综合影响，其内生细菌可能在PAH污染沉积物的植物修复潜力中发挥重要作用。
