Synergistic effect of Pseudomonas putida II-2 and Achromobacter sp. QC36 for the effective biodegradation of the herbicide quinclorac

• Published in: Ecotoxicology and environmental safety 2020-01, Vol.188, p.109826, Article 109826
• Main Authors: Yang, Yingjie, Pratap Singh, Raghvendra, Song, Dean, Chen, Qianru, Zheng, Xuebo, Zhang, Chengsheng, Zhang, Minggang, Li, Yiqiang
• Format: Article
• Language: English
• Subjects: 16S high-throughput sequencing; Achromobacter; Achromobacter - growth & development; Achromobacter - metabolism; Biodegradation; Biodegradation, Environmental; Herbicides - analysis; Oryza - growth & development; Pseudomonas; Pseudomonas putida - growth & development; Pseudomonas putida - metabolism; Quinclorac; Quinolines - analysis; RNA, Ribosomal, 16S - genetics; Soil - chemistry; Soil Microbiology; Soil Pollutants - analysis
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2019.109826

Quinclorac (QNC) is an effective but environmentally persistent herbicide commonly used in rice production. However, few studies have investigated its environmental behavior and degradation. In the present study, we carried out microbial cultures in the presence of QNC to observe changes in soil microbiota and to identify species capable of QNC degradation by using high-throughput sequencing of the 16S rRNA. Pseudomonas was the dominant genus, and Pseudomonas putida II-2 and other species were found to be capable of mineralizing QNC as a source of carbon and energy. However, this degradation rate was slow, only reaching 51.5 ± 1.6% for 7 days at 30 °C on QNC + minimal salt medium. Achromobacter sp. QC36 co-metabolized QNC when rice straw was added into the mineral salt medium containing QNC, and a mixed culture of both strains could mineralize approximately 92% of the 50 mg/L QNC after 5 days of cultivation in the presence of rice straw, at 25–35 °C and pH 6.0–8.0. Non-phytotoxicity of tobacco after degradation of QNC by mixed strains was evidenced in a pot experiment. These results suggest that this mixed culture may be useful in QNC bioremediation and can be used as a bio-formulation for agro-economical and industrial application. [Display omitted] •. Quinclorac-degrading microbiota were investigated by 16S replicon sequencing.•. A dominant species of Pseudomonas which degraded quinclorac was isolated and identified.•. Achromobacter sp. can co-metabolize the quinclorac when rice straw powder was supplemented.•. Mixed culture significantly reduced phytotoxicity to tobacco.•. A draft genome of the dominant Pseudomonas strain was constructed and analyzed.