title: Plant-microbe association for rhizoremediation of chloronitroaromatic pollutants with Comamonas sp. strain CNB-1.
abstract: 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.
authors.affiliation: State Key Laboratory of Microbial Resource, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.forename: Cheng-Ying
authors.initials: CY
authors.lastname: Jiang
authors.forename: Xing-Yu
authors.initials: XY
authors.lastname: Liu
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Wu
authors.forename: Ji-Gang
authors.initials: JG
authors.lastname: Han
authors.forename: Shuang-Jiang
authors.initials: SJ
authors.lastname: Liu
mesh_terms: 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
chemical_list: D009578:Nitrobenzenes; D012989:Soil Pollutants; D049452:Green Fluorescent Proteins; C010407:4-chloronitrobenzene; D009601:Nitroreductases