College of Environment and Safety, Taiyuan University of Science and Technology, Taiyuan 030024, Shanxi Province, China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
Sci Total Environ. 2021 Jun 1;771:144751. doi: 10.1016/j.scitotenv.2020.144751. Epub 2021 Jan 27.
This study investigated the effects of applying different biochars to soil on shifts in the bacterial community, the biodegradation of antibiotics, and their relationships. In total, nine biochars were applied to agricultural soil contaminated with 16 antibiotics. Clustering analysis showed that the responses of bacteria at the genus level to biochars were highly dependent on the biochar feedstock rather than the pyrolysis temperature. Among the antibiotics tested in the study, the biodegradation percentage was lower for tetracyclines (TCs, 6-14%) than sulfonamides (SAs, 8-26%) and quinolones (QLs, 8-24%). For specific individual antibiotics from the same class with similar structures, the high adsorption affinity of soil particles for antibiotics due to hydrophobic interactions (logK) and electrostatic interactions (pK) resulted in low biodegradation percentages for antibiotics in the soil. The biodegradation of TCs was affected more by the biochar type (effect size: -10% to 42%) than those of QLs (-26% to 14%) and SAs (-24% to 22%). According to the relationships determined between the bacterial taxonomic composition and biodegradation of antibiotics, Steroidobacter from the phylum Proteobacteria has significant positive correlations with the biodegradation of all SAs (p < 0.01), thereby indicating that Steroidobacter had a high capacity for biodegrading SAs. Significant positive correlations were also detected (p < 0.05) between specific genera (Iamia, Parviterribacter, and Gaiella) from the phylum Actinobacteria and the biodegradation of SAs. No significant positive correlations were found between bacterial genera and the biodegradation percentages for QLs and TCs, possibly due to the specific microorganisms involved in these biodegradation processes. The results in this study provide insights into the biodegradation mechanisms of antibiotics in soil and they may facilitate the development of strategies for the bioremediation of antibiotic-contaminated soil.
本研究考察了向受 16 种抗生素污染的农业土壤施加不同生物炭对细菌群落变化、抗生素生物降解及其关系的影响。总共向受污染的土壤施加了 9 种生物炭。聚类分析表明，细菌属水平对生物炭的反应高度依赖于生物炭原料而不是热解温度。在所研究的抗生素中，四环素（TCs，6-14%）的生物降解率低于磺胺类（SAs，8-26%）和喹诺酮类（QLs，8-24%）。对于具有相似结构的同类型特定抗生素，由于疏水性相互作用（logK）和静电相互作用（pK），土壤颗粒对抗生素的高吸附亲和力导致土壤中抗生素的生物降解率较低。TCs 的生物降解受生物炭类型的影响（效应大小：-10%至 42%）大于 QLs（-26%至 14%）和 SAs（-24%至 22%）。根据细菌分类组成与抗生素生物降解之间确定的关系，变形菌门的 Steroidobacter 与所有 SAs 的生物降解呈显著正相关（p < 0.01），表明 Steroidobacter 具有较高的 SAs 生物降解能力。放线菌门的特定属（Iamia、Parviterribacter 和 Gaiella）与 SAs 的生物降解之间也检测到显著正相关（p < 0.05）。细菌属与 QLs 和 TCs 的生物降解率之间未发现显著正相关，可能是由于涉及这些生物降解过程的特定微生物。本研究结果深入了解了土壤中抗生素的生物降解机制，并可能有助于开发受抗生素污染土壤的生物修复策略。
