Teng Ying, Li Xiufen, Chen Ting, Zhang Manyun, Wang Xiaomi, Li Zhengao, Luo Yongming
a Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences , Nanjing China.
b University of Chinese Academy of Sciences , Beijing China.
Int J Phytoremediation. 2016;18(2):141-9. doi: 10.1080/15226514.2015.1073667.
A bacterial strain ZY1 capable of utilizing PCBs as its carbon source was isolated from the root nodules of Chinese milk vetch (Astragalus sinicus L.). The strain was identified as Mesorhizobium sp. according to its physiological-biochemical properties and the analysis of its 16S rRNA gene sequence. When the initial OD600 was 0.15, 62.7% of 15 mg L(-1) 3,3',4,4'-TCB in a liquid culture was degraded by Mesorhizobium sp. ZY1 within 10 days. Mesorhizobium sp. ZY1 also greatly increased the biotransformation of soil PCBs. Pot experiments indicated that the soil PCB concentrations of a single incubation of strain ZY1 (R) and a single planting of A. sinicus (P) decreased by 20.5% and 23.0%, respectively, and the concentration of PCBs in soil treated with A. sinicus and strain ZY1 decreased by 53.1%. We also observed that A. sinicus-Mesorhizobium sp. ZY1 treatment (PR) improved plant biomass and the concentration of PCBs in plants compared with a single A. sinicus planting treatment (P). The results suggest that the synergistic association between A. sinicus and PCBs-degrading Mesorhizobium sp. ZY1 can stimulate the phytoextraction of PCBs and the rhizosphere microflora to degrade PCBs, and might be a promising bioremediation strategy for PCB-contaminated soil.
从紫云英（Astragalus sinicus L.）根瘤中分离出一株能够以多氯联苯为碳源的细菌菌株ZY1。根据其生理生化特性和16S rRNA基因序列分析，该菌株被鉴定为中生根瘤菌属（Mesorhizobium sp.）。当初始OD600为0.15时，中生根瘤菌属ZY1在10天内可降解液体培养物中15 mg L(-1)的3,3',4,4'-四氯联苯的62.7%。中生根瘤菌属ZY1还显著提高了土壤中多氯联苯的生物转化。盆栽试验表明，单独接种菌株ZY1（R）和单独种植紫云英（P）后，土壤中多氯联苯浓度分别降低了20.5%和23.0%，而紫云英和菌株ZY1共同处理的土壤中多氯联苯浓度降低了53.1%。我们还观察到，与单独种植紫云英处理（P）相比，紫云英-中生根瘤菌属ZY1处理（PR）提高了植物生物量和植物中多氯联苯的浓度。结果表明，紫云英与降解多氯联苯的中生根瘤菌属ZY1之间的协同联合可以促进多氯联苯的植物提取以及根际微生物群落对多氯联苯的降解，这可能是一种用于多氯联苯污染土壤的有前景的生物修复策略。
