Plant-microbe association for rhizoremediation of chloronitroaromatic pollutants with Comamonas sp. strain CNB-1.
Comamonas sp. strain CNB-1, isolated from activated sludge and having a strong ability to degrade 4-chloronitrobenzene (4CNB), was applied for rhizoremediation of 4CNB-polluted soil through association with alfalfa. Confocal laser scanning microscopy revealed that strain CNB-1 successfully colonized alfalfa roots. Determination of strain CNB-1 populations by cultivation method and by quantitative competitive PCR technique targeting the chloronitrobenzene nitroreductase gene showed that the population of strain CNB-1 in the rhizosphere was about 10-100 times higher than that in the bulk soil. Gnotobiotic and outdoor experiments showed that pollutant 4CNB was completely removed within 1 or 2 days after 4CNB application into soil, and that its phytotoxicity to alfalfa was eliminated by inoculation of strain CNB-1. Results from PCR-denaturing gradient gel electrophoresis and analysis of 16S rRNA gene libraries revealed that the indigenous soil microbial community mainly consisted of alphaproteobacteria, betaproteobacteria, gammaproteobacteria, the CFB bacteria (Cytophaga-Flavabacterium-Bacteriodes), and Acidobacteria. This microbial community was not significantly influenced by inoculation of strain CNB-1. Thus, this study has developed a Comamonas-alfalfa system for rhizoremediation of 4CNB.
Liu
Lei
L
State Key Laboratory of Microbial Resource, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, China.
Jiang
Cheng-Ying
CY
Liu
Xing-Yu
XY
Wu
Jian-Feng
JF
Han
Ji-Gang
JG
Liu
Shuang-Jiang
SJ
D001673:Biodegradation, Environmental; D020585:Comamonas / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000032:analysis; D000455:Medicago sativa / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D009578:Nitrobenzenes / Q000378:metabolism* / Q000633:toxicity; D009601:Nitroreductases / Q000235:genetics; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D016133:Polymerase Chain Reaction; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity
D009578:Nitrobenzenes; D012989:Soil Pollutants; D049452:Green Fluorescent Proteins; C010407:4-chloronitrobenzene; D009601:Nitroreductases