School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, Shaanxi, China.
Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE, Xi'an, China.
Environ Sci Pollut Res Int. 2023 May;30(23):64300-64312. doi: 10.1007/s11356-023-26909-2. Epub 2023 Apr 17.
Soil bacteria that produce biosurfactants can use total petroleum hydrocarbons (TPHs) as a carbon source. This study demonstrated that biosurfactants produced by Burkholderia sp. enhanced the recovery and synergism of soil microbial community, resulting in fast degradation of macro alkanes. Experiments were carried out by applying bio-stimulation after pre-oxidation to investigate the effects of nutrient addition on biosurfactant production, TPH degradation, and microbial community succession in the soil. The results presented that bio-stimulation could produce biosurfactants in high C/N (32.6) and C/H (13.3) conversion after pre-oxidation and increased the total removal rate of TPH (10.59-46.71%). The number of total bacteria had a rapid increase trend (2.94-8.50 Log CFU/g soil). The degradation rates of macro alkanes showed a 4.0-fold (48.07 mg/kg·d versus 186.48 mg/kg·d) increase, and the bioremediation time of degrading macro alkanes saved 166 days. Further characterization revealed that the biosurfactants produced by Burkholderia sp. could activate indigenous bacteria to degrade macro alkanes rapidly. A shift in phylum from Actinomycetes to Proteobacteria was observed during bioremediation. The average relative abundance of the microbial community increased from 36.24 to 64.96%, and the predominant genus tended to convert from Allorhizobium (8.57%) to Burkholderia (15.95%) and Bacillus (15.70%). The co-occurrence network and Pearson correlation analysis suggested that the synergism of microbial community was the main reason for the fast degradation of macro alkanes in petroleum-contaminated soils. Overall, this study indicated the potential of the biosurfactants to activate and enhance the recovery of indigenous bacteria after pre-oxidation, which was an effective method to remediate petroleum-contaminated soils.
能够产生生物表面活性剂的土壤细菌可以将总石油烃 (TPH) 用作碳源。本研究表明，伯克霍尔德氏菌产生的生物表面活性剂增强了土壤微生物群落的回收和协同作用，导致长链烷烃的快速降解。通过在预氧化后进行生物刺激实验，研究了营养物质添加对生物表面活性剂产生、TPH 降解和土壤微生物群落演替的影响。结果表明，生物刺激可以在预氧化后产生高 C/N（32.6）和 C/H（13.3）转化率的生物表面活性剂，并提高 TPH 的总去除率（10.59-46.71%）。总细菌数量呈快速增长趋势（2.94-8.50 Log CFU/g 土壤）。长链烷烃的降解率提高了 4.0 倍（48.07 mg/kg·d 对 186.48 mg/kg·d），降解长链烷烃的生物修复时间节省了 166 天。进一步的表征表明，伯克霍尔德氏菌产生的生物表面活性剂可以激活土著细菌快速降解长链烷烃。在生物修复过程中，从放线菌门到变形菌门的门水平发生了转变。微生物群落的平均相对丰度从 36.24%增加到 64.96%，优势属从根瘤菌（8.57%）倾向于转化为伯克霍尔德氏菌（15.95%）和芽孢杆菌（15.70%）。共生网络和 Pearson 相关分析表明，微生物群落的协同作用是石油污染土壤中长链烷烃快速降解的主要原因。总的来说，本研究表明生物表面活性剂在预氧化后具有激活和增强土著细菌回收的潜力，是一种有效的石油污染土壤修复方法。
