School of Environmental Science and Engineering, Tianjin University, 92 Weijin Road, Tianjin, 300072, China.
School of Environmental Science and Engineering, Tianjin University, 92 Weijin Road, Tianjin, 300072, China.
Chemosphere. 2022 Nov;307(Pt 1):135783. doi: 10.1016/j.chemosphere.2022.135783. Epub 2022 Jul 19.
Benzophenone-3 (BP-3) is an emerging environmental pollutant used in personal care products, helping to reduce the risk of ultraviolet radiation to human skin. The BP-3 removal potential from soil by tobacco (Nicotiana tabacum) assisted with Methylophilus sp. FP-6 was explored in our previous study. However, the reduced BP-3 remediation efficiency by FP-6 in soil and the inhibited plant growth by BP-3 limited the application of this phytoremediation strategy. The aim of the present study was to reveal the potential roles of betaine, as the methyl donor of methylotrophic bacteria and plant regulator, in improving the strain FP-6-assisted phytoremediation capacity of BP-3 contaminated soil. The results revealed that strain FP-6 could use betaine as a co-metabolism substrate to enhance the BP-3 degradation activity. About 97.32% BP-3 in soil was effectively removed in the phytoremediation system using tobacco in combination with FP-6 and betaine for 40 d while the concentration of BP-3 in tobacco significantly reduced. Moreover, the biomass and photosynthetic efficiency of plants were remarkably improved through the combined treatment of betaine and strain FP-6. Simultaneously, inoculation of FP-6 in the presence of betaine stimulated the change of local microbial community structure, which might correlate with the production of a series of hydrolases and reductases involved in soil carbon, nitrogen and phosphorus cycling processes. Meantime, some of the dominant bacteria could secrete various multiple enzymes involved in degrading organic pollutants, such as laccase, to accelerate the demethylation and hydroxylation of BP-3. Overall, the results from this study proposed that the co-metabolic role of betaine could be utilized to strengthen microbial-assisted phytoremediation process by increasing the degradation ability of methylotrophic bacteria and enhancing plant tolerance to BP-3. The present results provide novel insights and perspectives for broadening the engineering application scope of microbial-assisted phytoremediation of organic pollutants without sacrificing economic crop safety.
二苯甲酮-3（BP-3）是一种新兴的环境污染物，用于个人护理产品，有助于降低人类皮肤暴露于紫外线辐射的风险。在我们之前的研究中，探索了利用甲基杆菌（Methylophilus sp.）FP-6 辅助烟草（Nicotiana tabacum）从土壤中去除 BP-3 的潜力。然而，FP-6 在土壤中的 BP-3 修复效率降低以及 BP-3 对植物生长的抑制限制了这种植物修复策略的应用。本研究的目的是揭示甜菜碱作为甲基营养型细菌和植物调节剂的供甲基体的潜在作用，以提高菌株 FP-6 辅助 BP-3 污染土壤的植物修复能力。结果表明，菌株 FP-6 可以利用甜菜碱作为共代谢底物来增强 BP-3 的降解活性。在使用烟草与 FP-6 和甜菜碱联合处理 40 天后，土壤中约 97.32%的 BP-3 被有效去除，而烟草中的 BP-3 浓度显著降低。此外，通过甜菜碱和菌株 FP-6 的联合处理，显著提高了植物的生物量和光合作用效率。同时，在存在甜菜碱的情况下接种 FP-6 刺激了局部微生物群落结构的变化，这可能与一系列涉及土壤碳、氮和磷循环过程的水解酶和还原酶的产生有关。同时，一些优势细菌可以分泌各种参与降解有机污染物的多酶，如漆酶，以加速 BP-3 的脱甲基和羟化。总的来说，本研究的结果表明，甜菜碱的共代谢作用可以通过增加甲基营养型细菌的降解能力和增强植物对 BP-3 的耐受性来加强微生物辅助植物修复过程。本研究结果为拓宽微生物辅助植物修复有机污染物的工程应用范围提供了新的思路和视角，同时不牺牲经济作物的安全性。
