Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China.
MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Sci Total Environ. 2024 Nov 15;951:175772. doi: 10.1016/j.scitotenv.2024.175772. Epub 2024 Aug 25.
In this study, sophorolipids (SLs)-modified biochar (BC-SLs) was used to enhance the bioremediation of petroleum hydrocarbons (PHs) contaminated soil. The biodegradation rate of petroleum hydrocarbons (PHs) by BC-SLs and BC treatments were 62.86 % and 52.64 % after 60 days of remediation experiments, respectively, higher than non-biochar treatment group (24.09 %). The metagenomic analysis showed that the abundance of petroleum-degrading bacteria Actinobacteria and Proteobacteria were increased by 3.8 % and 5.3 %, respectively in BC-SLs treatment, and the abundance of functional genes for PHs degradation, such as alkB, nidA and pcaG, were significantly increased by 12.85 %, 30.08 % and 21.01 %, respectively. The metabolomic analysis showed that BC-SLs facilitated the metabolic process of PHs, the microbial metabolism of petroleum hydrocarbons (PHs) became more active. Fatty acid degradation and polycyclic aromatic hydrocarbons (PAHs) degradation were up-regulated, indicating the promoting effect of the BC-SLs for PHs metabolism. The combined metagenomic and metabolomic analysis demonstrated the strong positive correlations between PHs metabolites and PHs-degrading bacteria, such as lauric acid vs. Actinobacteria, benzoic vs. Proteobacteria. The strong positive correlations between PHs metabolites and PHs-degrading genes were also observed, such as o-ehyltoluene vs. nahD, 4-isopropylbenzoic acid vs. etbAa. The modification of biochar with SLs increased the oxygen-containing functional groups on the surface of biochar. Meanwhile, the emulsification and solubilization of SLs promoted the bioavailability of PHs. The effects of BC-SLs on the nitrogen cycle during PHs remediation showed that it facilitated the accumulation of nitrogen-fixing genes, promoted nitrification but inhibited denitrification process. This study confirms that the application of BC-SLs is an effective remediation of PHs contamination and a sustainable method for controlling agricultural waste resources.
在这项研究中，利用槐糖脂（SLs）修饰生物炭（BC-SLs）来增强受石油烃（PHs）污染土壤的生物修复。在 60 天的修复实验后，BC-SLs 和 BC 处理的石油烃（PHs）生物降解率分别为 62.86%和 52.64%，高于非生物炭处理组（24.09%）。宏基因组分析表明，BC-SLs 处理组中降解石油的细菌放线菌和变形菌的丰度分别增加了 3.8%和 5.3%，同时，降解 PHs 的功能基因 alkB、nidA 和 pcaG 的丰度分别显著增加了 12.85%、30.08%和 21.01%。代谢组学分析表明，BC-SLs 促进了 PHs 的代谢过程，使微生物对石油烃（PHs）的代谢更加活跃。脂肪酸降解和多环芳烃（PAHs）降解被上调，表明 BC-SLs 对 PHs 代谢具有促进作用。宏基因组和代谢组学联合分析表明，PHs 代谢物与 PHs 降解细菌之间存在很强的正相关关系，如月桂酸与放线菌、苯甲酸与变形菌。还观察到 PHs 代谢物与 PHs 降解基因之间存在很强的正相关关系，如邻-乙基甲苯与 nahD、4-异丙基苯甲酸与 etbAa。SLs 对生物炭的修饰增加了生物炭表面的含氧官能团。同时，SLs 的乳化和增溶作用提高了 PHs 的生物利用度。BC-SLs 对 PHs 修复过程中氮循环的影响表明，它促进了固氮基因的积累，促进了硝化作用，但抑制了反硝化过程。本研究证实，BC-SLs 的应用是一种有效的 PHs 污染修复方法，也是控制农业废弃物资源的可持续方法。
