Zhang Ben, Xu Wei, Ma Yichi, Gao Xiaolong, Ming Huyang, Jia Jianli
School of Chemical and Environmental Engineering, China University of Mining & Technology (Beijing), Beijing, 100083, PR China.
School of Chemical and Environmental Engineering, China University of Mining & Technology (Beijing), Beijing, 100083, PR China.
J Environ Manage. 2023 May 15;334:117491. doi: 10.1016/j.jenvman.2023.117491. Epub 2023 Feb 18.
Polycyclic aromatic hydrocarbons (PAHs) are a group of organic pollutants ubiquitous and persistent in soil. In order to provide a viable solution for bioremediation of PAHs-contaminated soil, a strain of Achromobacter xylosoxidans BP1 with superior PAHs degradation ability was isolated from contaminated soil at a coal chemical site in northern China. The degradation of phenanthrene (PHE) and benzo[a]pyrene (BaP) by strain BP1 was investigated in three different liquid phase cultures, and the removal rates of PHE and BaP by strain BP1 were 98.47% and 29.86% after 7 days under the conditions of PHE and BaP as the only carbon source, respectively. In the medium with the coexistence of PHE and BaP, the removal rates of BP1 were 89.44% and 9.42% after 7 days, respectively. Then, strain BP1 was investigated for its feasibility in remediating PAH-contaminated soil. Among the four PAHs-contaminated soils treated differently, the treatment inoculated with BP1 exhibited higher removal rates of PHE and BaP (p < 0.05), especially the CS-BP1 treatment (inoculation of BP1 into unsterilized PAHs-contaminated soil) showed 67.72%, 13.48% removal of PHE and BaP, respectively, over 49 days of incubation. Bioaugmentation also significantly increased the activity of dehydrogenase and catalase in the soil (p＜0.05). Furthermore, the effect of bioaugmentation on the removal of PAHs was investigated by measuring the activity of dehydrogenase (DH) and catalase (CAT) during incubation. Among them, the DH and CAT activities of CS-BP1 and SCS-BP1 (inoculation of BP1 into sterilized PAHs-contaminated soil) treatments inoculated with strain BP1 were significantly higher than those of treatments without BP1 addition during incubation (p < 0.01). The structure of the microbial community varied among treatments, but the Proteobacteria phylum showed the highest relative abundance in all treatments of the bioremediation process, and most of the bacteria with higher relative abundance at the genus level also belonged to the Proteobacteria phylum. Prediction of microbial functions in soil by FAPROTAX analysis showed that bioaugmentation enhanced microbial functions associated with the degradation of PAHs. These results demonstrate the effectiveness of Achromobacter xylosoxidans BP1 as a PAH-contaminated soil degrader for the risk control of PAHs contamination.
多环芳烃（PAHs）是一类在土壤中普遍存在且持久的有机污染物。为了为PAHs污染土壤的生物修复提供可行的解决方案，从中国北方某煤化工场地的污染土壤中分离出了一株具有优异PAHs降解能力的木糖氧化无色杆菌BP1。在三种不同的液相培养物中研究了菌株BP1对菲（PHE）和苯并[a]芘（BaP）的降解情况，在以PHE和BaP作为唯一碳源的条件下，7天后菌株BP1对PHE和BaP的去除率分别为98.47%和29.86%。在PHE和BaP共存的培养基中，7天后BP1对它们的去除率分别为89.44%和9.42%。然后，研究了菌株BP1修复PAH污染土壤的可行性。在四种不同处理的PAHs污染土壤中，接种BP1的处理对PHE和BaP的去除率更高（p < 0.05），特别是CS - BP1处理（将BP1接种到未灭菌的PAHs污染土壤中）在49天的培养期内对PHE和BaP的去除率分别达到了67.72%和13.48%。生物强化还显著提高了土壤中脱氢酶和过氧化氢酶的活性（p＜0.05）。此外，通过在培养过程中测量脱氢酶（DH）和过氧化氢酶（CAT）的活性来研究生物强化对PAHs去除的影响。其中，接种菌株BP1的CS - BP1和SCS - BP1（将BP1接种到灭菌的PAHs污染土壤中）处理在培养过程中的DH和CAT活性显著高于未添加BP1的处理（p < 0.01）。不同处理间微生物群落结构存在差异，但在生物修复过程的所有处理中，变形菌门的相对丰度最高，属水平上相对丰度较高的大多数细菌也属于变形菌门。通过FAPROTAX分析对土壤中微生物功能的预测表明，生物强化增强了与PAHs降解相关的微生物功能。这些结果证明了木糖氧化无色杆菌BP1作为PAH污染土壤降解菌在控制PAHs污染风险方面的有效性。
