title: Role of plant growth-promoting Ochrobactrum sp. MC22 on triclocarban degradation and toxicity mitigation to legume plants.
abstract: Triclocarban (TCC) is an emerging and persistent pollutant once released into environment. In this study, TCC-degrading Ochrobactrum sp. MC22, was isolated and characterized. This is the first report on plant-growth promoting bacterium with versatile capability of TCC degradation under aerobic and anaerobic conditions. The aerobic degradation of TCC occurred completely of which the kinetic analysis revealed a non-self-inhibitive substrate effect, and broad-concentration-range degradation efficiency (ranging from 0.16-30mgL-1). Anaerobic TCC degradation was feasible, but was significantly enhanced up to 40-50% when ferric, or acetate was provided as electron donor, or acceptor, respectively. TCC biodegradation under both conditions was proposed to initially occur through hydrolysis leading to transient accumulation of chloroanilines, which could be completely metabolized and detoxified. With concern on TCC adverse effect to plants, role of MC22 on toxicity mitigation was investigated using two legume plants: Vigna radiata and Glycine max (L.) Merr. Upon TCC exposure, damage of both plant structures, especially root system was observed, but was substantially mitigated by MC22 bioaugmentation. This study not only provides thorough TCC degradation characteristic and kinetics of MC22, but also suggests a potential role of this bacterial strain for a rhizoremediation in crop area with TCC contamination.
authors.affiliation: Biological Sciences Program, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand; Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Merry Krisdawati
authors.initials: MK
authors.lastname: Sipahutar
authors.affiliation: Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand; Center of Excellence on Hazardous Substance Management (HSM), Chulalongkorn University, Bangkok 10330, Thailand. Electronic address: avangnai@yahoo.com.
authors.forename: Alisa S
authors.initials: AS
authors.lastname: Vangnai
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D002224:Carbanilides / Q000378:metabolism* / Q000633:toxicity; D009152:Mutagenicity Tests; D042041:Ochrobactrum / Q000302:isolation & purification* / Q000378:metabolism; D019697:Onions; D063245:Plant Development; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity; D013025:Glycine max / Q000187:drug effects*; D000070658:Vigna / Q000187:drug effects*
chemical_list: D002224:Carbanilides; D012989:Soil Pollutants; C009540:triclocarban
keywords: Aerobic and anaerobic degradation; Ochrobactrum sp. MC22; Plant-growth promoting bacteria; Toxicity mitigation; Triclocarban