State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
Sci Total Environ. 2020 Jun 1;719:137456. doi: 10.1016/j.scitotenv.2020.137456. Epub 2020 Feb 19.
Bioremediation is considered a cost-effective and environmentally sound method for degradation of petroleum hydrocarbons in contaminated soils. This study investigated the effects of biosurfactant alkyl polyglycosides (APG) on enhanced biodegradation of petroleum hydrocarbon-contaminated soils using Sphingomonas changbaiensis and Pseudomonas stutzeri and explored the mechanism responsible for the enhanced petroleum hydrocarbon degradation. To accomplish this, the following treatments were evaluated: (1) bioaugmentation with Sphingomonas changbaiensis; (2) bioaugmentation with Pseudomonas stutzeri; (3) a combination of Sphingomonas changbaiensis and APG; and (4) a combination of Pseudomonas stutzeri and APG. The results showed that the degradation rates of total petroleum hydrocarbons (TPH) in contaminated soil samples bioaugmented with S. changbaiensis and P. stutzeri for 30 days were 39.2 ± 1.9% and 47.2 ± 1.2%, respectively. The addition of biosurfactant APG enhanced the bioremediation processes and improved the biodegradation rates. The biodegradation rate at 1.5 g/kg APG in soil samples bioaugmented with S. changbaiensis was 52.1 ± 2.0%, while the rate at 1.5 g/kg APG in soil samples bioaugmented with P. stutzeri was 59.0 ± 1.8%. The half-life decreased from 39.7 d to 24.5 d and from 29.6 to 20.1 d when the dosage of APG was 1.5 g/kg in contaminated soil samples bioaugmented with S. changbaiensis and P. stutzeri, respectively. Mechanism studies showed that the addition of APG can increase the TPH solubility, promote the sorption of TPH onto microbial cells and subsequent trans-membrane transport by APG-induced structural changes, stimulate microbial activities and participate in the co-metabolism. Therefore, the combination of bioaugmentation and APG is an effective method for remediation of petroleum hydrocarbon-contaminated soil.
生物修复被认为是一种经济有效的、环境友好的方法，可用于降解污染土壤中的石油烃。本研究采用鞘氨醇单胞菌（Sphingomonas changbaiensis）和施氏假单胞菌（Pseudomonas stutzeri），研究了生物表面活性剂烷基糖苷（APG）对石油烃污染土壤强化生物降解的影响，并探讨了促进石油烃降解的作用机制。为此，评估了以下处理方法：（1）生物强化接种鞘氨醇单胞菌；（2）生物强化接种施氏假单胞菌；（3）鞘氨醇单胞菌与 APG 的组合；（4）施氏假单胞菌与 APG 的组合。结果表明，生物强化接种鞘氨醇单胞菌和施氏假单胞菌 30 天后，污染土壤中总石油烃（TPH）的降解率分别为 39.2±1.9%和 47.2±1.2%。添加生物表面活性剂 APG 可增强生物修复过程，提高生物降解率。在添加 1.5 g/kg APG 的土壤样品中，生物强化接种鞘氨醇单胞菌的生物降解率为 52.1±2.0%，而生物强化接种施氏假单胞菌的生物降解率为 59.0±1.8%。当添加 1.5 g/kg APG 时，生物强化接种鞘氨醇单胞菌和施氏假单胞菌的污染土壤中 TPH 的半衰期分别从 39.7 d 缩短至 24.5 d 和从 29.6 d 缩短至 20.1 d。机制研究表明，APG 的添加可以增加 TPH 的溶解度，促进 TPH 通过 APG 诱导的结构变化吸附到微生物细胞上，并随后进行跨膜运输，刺激微生物活性并参与共代谢。因此，生物强化与 APG 联合是一种有效的石油烃污染土壤修复方法。
