School of Resource and Environmental Sciences, Hubei Key Laboratory of Biomass-Resources Chemistry and Environmental Biotechnology, Hubei Research Center of Environment Remediation Technology, Wuhan University, Wuhan, 430079, China.
School of Resource and Environmental Sciences, Hubei Key Laboratory of Biomass-Resources Chemistry and Environmental Biotechnology, Hubei Research Center of Environment Remediation Technology, Wuhan University, Wuhan, 430079, China.
Chemosphere. 2023 Aug;331:138732. doi: 10.1016/j.chemosphere.2023.138732. Epub 2023 Apr 29.
Plant-growth-promoting rhizobacteria (PGPR) have received increasing attention for assisting phytoremediation. However, the effect of PGPR on total petroleum hydrocarbon (TPH) degradation and plant growth promotion and its underlying mechanism is not well understood. In this study, phenotypic analysis and whole genome sequencing were conducted to comprehensively characterize a newly isolated rhizobacterium strain S4, which was identified as Acinetobacter oleivorans, from a TPH-contaminated soil. The strain degraded 62.5% of initially spiked diesel (1%) in minimal media within six days and utilized n-alkanes with a wide range of chain length (i.e., C to C). In addition, the strain showed phenotypic traits beneficial to plant growth, including siderophore production, indole-3-acetic acid synthesis and phosphate solubilization. Potential metabolic pathways and genes encoding proteins responsible for the phenotypic traits were identified. In a real TPH-contaminated soil, inoculation of Acinetobacter oleivorans S4 significantly enhanced the growth of tall fescue relative to the soil without inoculation. In contrast, inoculation of Bacillus sp. Z7, a hydrocarbon-degrading strain, showed a negligible effect on the growth of tall fescue. The removal efficiency of TPH with inoculation of Acinetobacter oleivorans S4 was significantly higher than those without inoculation or inoculation of Bacillus sp. Z7. These results suggested that traits of PGPR beneficial to plant growth are critical to assist phytoremediation. Furthermore, heavy metal resistance genes and benzoate and phenol degradation genes were found in the genome of Acinetobacter oleivorans S4, suggesting its application potential in broad scenarios.
植物促生根际细菌（PGPR）在协助植物修复方面受到了越来越多的关注。然而，PGPR 对总石油烃（TPH）降解和植物生长促进的影响及其潜在机制尚不清楚。在这项研究中，通过表型分析和全基因组测序，对从 TPH 污染土壤中分离得到的新的根际细菌菌株 S4 进行了全面表征，该菌株被鉴定为不动杆菌 oleivorans。该菌株在最小培养基中在六天内降解了最初添加的柴油（1%）的 62.5%，并利用了具有广泛链长（即 C 至 C）的正烷烃。此外，该菌株表现出有利于植物生长的表型特征，包括产生铁载体、合成吲哚-3-乙酸和溶解磷酸盐。鉴定了潜在的代谢途径和编码负责表型特征的蛋白质的基因。在真正的 TPH 污染土壤中，与未接种的土壤相比，接种不动杆菌 oleivorans S4 显著促进了高羊茅的生长。相比之下，接种烃降解菌株 Bacillus sp. Z7 对高羊茅的生长几乎没有影响。接种不动杆菌 oleivorans S4 后 TPH 的去除效率明显高于未接种或接种 Bacillus sp. Z7 的情况。这些结果表明，有利于植物生长的 PGPR 特征对于协助植物修复至关重要。此外，在不动杆菌 oleivorans S4 的基因组中发现了重金属抗性基因和苯甲酸和苯酚降解基因，这表明其在广泛的场景中有应用潜力。
