Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130021, China; Engineering Lab for Water Pollution Control and Resources Recovery of Jilin Province, School of Environment, Northeast Normal University, Changchun, 130117, China.
Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun, 130021, China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun, 130021, China.
J Hazard Mater. 2020 Jul 15;394:122574. doi: 10.1016/j.jhazmat.2020.122574. Epub 2020 Mar 21.
β-Lactam antibiotics are the most commonly used antibiotics, and are difficult to remove by conventional biological treatments because of their persistent and toxic nature. The addition of co-substrates has been successfully employed to improve the removal of refractory pollutants. So, we hypothesized that the co-substrate strategy would increase antibiotic degradation and benefit microbial survival. In this work, we reported that co-substrate (acetate) addition up-regulated key degrading enzymes and resistance related genes in a model bacteria strain (L. aquatilis) when being treated with 0.055 mM amoxicillin (AMO). β-Lactamase, amidases, transaminase, and amide C-N hydrolase showed increased activation. As a result, AMO removal reached ∼95 %, a ∼60 % increase over the control. Furthermore, the addition of acetate drove the down-stream TCA cycle, which accelerated the detoxification of the intermediates and reduced the microbial inhibition by the antibiotic products to as low as ∼15 %. Besides, the expression levels of genes encoding the efflux pump, penicillin binding proteins, and β-Lactamase were up-regulated, and the inhibition of peptidoglycan biosynthesis was down-regulated. The cell density was enhanced by ∼170 % and showed improved DNA replication. In conclusion, the addition of the co-substrate accelerated AMO degradation and detoxification by up-regulating degrading enzymes and promoting cell resistance.
β-内酰胺类抗生素是最常用的抗生素，由于其持久性和毒性，难以通过传统的生物处理去除。添加共基质已成功用于提高难降解污染物的去除率。因此，我们假设共基质策略将增加抗生素的降解并有利于微生物的存活。在这项工作中，我们报告了当用 0.055mM 阿莫西林（AMO）处理时，共基质（乙酸盐）的添加会在上调关键降解酶和抗性相关基因方面，在模型细菌菌株（L. aquatilis）中发挥作用。β-内酰胺酶、酰胺酶、转氨酶和酰胺 C-N 水解酶的活性增加。结果，AMO 的去除率达到了约 95%，比对照提高了约 60%。此外，乙酸盐的添加驱动了下游三羧酸循环，这加速了中间产物的解毒作用，并将抗生素产物对微生物的抑制作用降低到低至约 15%。此外，编码外排泵、青霉素结合蛋白和β-内酰胺酶的基因的表达水平上调，肽聚糖生物合成的抑制作用下调。细胞密度提高了约 170%，并显示出改善的 DNA 复制。总之，添加共基质通过上调降解酶和促进细胞抗性来加速 AMO 的降解和解毒。
