Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China; Advanced Water Technology Laboratory, National University of Singapore (Suzhou) Research Institute, Suzhou, Jiangsu 215123, China.
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Environ Pollut. 2024 Apr 15;347:123710. doi: 10.1016/j.envpol.2024.123710. Epub 2024 Mar 6.
There is a lack of knowledge on the biodegradation mechanisms of benzene and benzo [a]pyrene (BaP), representative compounds of polycyclic aromatic hydrocarbons (PAHs), and benzene, toluene, ethylbenzene, and xylene (BTEX), under individually and mixed contaminated soils. Therefore, a set of microcosm experiments were conducted to explore the influence of benzene and BaP on biodegradation under individual and mixed contaminated condition, and their subsequent influence on native microbial consortium. The results revealed that the total mass loss of benzene was 56.0% under benzene and BaP mixed contamination, which was less than that of individual benzene contamination (78.3%). On the other hand, the mass loss of BaP was slightly boosted to 17.6% under the condition of benzene mixed contamination with BaP from that of individual BaP contamination (14.4%). The significant differences between the microbial and biocide treatments for both benzene and BaP removal demonstrated that microbial degradation played a crucial role in the mass loss for both contaminants. In addition, the microbial analyses revealed that the contamination of benzene played a major role in the fluctuations of microbial compositions under co-contaminated conditions. Rhodococcus, Nocardioides, Gailla, and norank_c_Gitt-GS-136 performed a major role in benzene biodegradation under individual and mixed contaminated conditions while Rhodococcus, Noviherbaspirillum, and Phenylobacterium were highly involved in BaP biodegradation. Moreover, binary benzene and BaP contamination highly reduced the Rhodococcus abundance, indicating the toxic influence of co-contamination on the functional key genus. Enzymatic activities revealed that catalase, lipase, and dehydrogenase activities proliferated while polyphenol oxidase was reduced with contamination compared to the control treatment. These results provided the fundamental information to facilitate the development of more efficient bioremediation strategies, which can be tailored to specific remediation of different contamination scenarios.
在单独和混合污染土壤中，苯和苯并[a]芘（BaP）、多环芳烃（PAHs）和苯、甲苯、乙苯和二甲苯（BTEX）的生物降解机制知识匮乏。因此，进行了一组微宇宙实验，以探索苯和 BaP 在单独和混合污染条件下对生物降解的影响，以及它们对本地微生物群落的后续影响。结果表明，在苯和 BaP 混合污染下，苯的总质量损失为 56.0%，低于单独苯污染（78.3%）的质量损失。另一方面，在苯与 BaP 混合污染条件下，BaP 的质量损失从单独 BaP 污染（14.4%）时略有增加到 17.6%。微生物和杀菌剂处理对苯和 BaP 去除的显著差异表明，微生物降解在两种污染物的质量损失中起着关键作用。此外，微生物分析表明，在共污染条件下，苯的污染对微生物组成的波动起着主要作用。在单独和混合污染条件下，节杆菌、诺卡氏菌、加氏菌和 norank_c_Gitt-GS-136 在苯生物降解中起主要作用，而节杆菌、新鱼腥藻和苯基杆菌则高度参与 BaP 生物降解。此外，二元苯和 BaP 污染极大地降低了节杆菌的丰度，表明共污染对功能关键属具有毒性影响。酶活性表明，与对照处理相比，污染后过氧化氢酶、脂肪酶和脱氢酶活性增加，多酚氧化酶活性降低。这些结果为开发更有效的生物修复策略提供了基础信息，这些策略可以针对特定的修复场景进行定制。
