Department of Environmental Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea.
Department of Botany & Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
Chemosphere. 2020 May;247:125948. doi: 10.1016/j.chemosphere.2020.125948. Epub 2020 Jan 17.
The present study explores the rapid chlopyrifos (CPs) biodegradation potential of plant growth promoting (PGP) psychrophilic bacteria isolated from brackish water by enrichment culture technique. Based on biochemical tests and 16 S rDNA sequencing the isolate was identified as Shewanella sp. The isolate Shewanella BT05 showed significant growth rate in various concentrations of (10-50 mg/L) CPs. The isolate produced plant growth promoting factors, IAA (20.8 ± 1.2 and 15.4 ± 1.0 μg/mL) and siderophores (60.67 ± 1.2 and 57.5 ± 0.9%) in the absence and presence of CPs. Further, the isolate BT05 solublized phosphate (16.5 ± 1.0 and 12.0 ± 1.0 mm in size respectively), and produce hydrogen cyanide (excellent and moderate) in the presence and absence of CPs. The isolate BT05 degraded 94.3, 91.8, 87.9, 82.6, and 80.5% of CPs at 10, 20, 30, 40, and 50 mg/L, respectively, within 24 h. Further, the media conditions were optimized for enhanced CPs removal and observed 93% removal in the presence of 3.5% glucose in pH 7.0 at 32.5 °C. Fourier-transform infrared spectroscopy and high-performance liquid chromatography results indicated the role for Shewanella BT05 in the biomineralization of CPs. The results suggested the isolate BT05 could be used for CPs removal as well as PGP activity in contaminated soil.
本研究通过富集培养技术，从咸水中分离出具有植物促生（PGP）能力的嗜冷菌，探索其对氯吡磷（CPs）的快速生物降解潜力。根据生化试验和 16S rDNA 测序，该分离株被鉴定为希瓦氏菌属（Shewanella）。分离株 Shewanella BT05 在不同浓度（10-50mg/L）CPs 中表现出显著的生长速率。在不存在和存在 CPs 的情况下，该分离株分别产生 20.8±1.2 和 15.4±1.0μg/mL 的植物生长素（IAA）和 60.67±1.2 和 57.5±0.9%的铁载体。此外，分离株 BT05 在不存在和存在 CPs 的情况下分别溶解磷酸盐（大小分别为 16.5±1.0 和 12.0±1.0mm）并产生氢氰酸（极好和中等）。分离株 BT05 在 10、20、30、40 和 50mg/L 下分别在 24 小时内降解了 94.3、91.8、87.9、82.6 和 80.5%的 CPs。进一步优化了培养基条件以增强 CPs 的去除，在 32.5°C、pH7.0 和 3.5%葡萄糖存在下观察到 93%的去除率。傅里叶变换红外光谱和高效液相色谱结果表明，希瓦氏菌 BT05 在 CPs 的生物矿化中起作用。结果表明，分离株 BT05 可用于 CPs 的去除以及污染土壤中的 PGP 活性。
