Abstract

In this study, the roles of extracellular polymeric substances (EPSs) excreted by Pandoraea sp. XY-2 in the removal of tetracycline (TC) were investigated. In the early stage, TC in the solution was mainly removed by the adsorption of EPSs, which accounted for 20% of TC. Thereafter, large amount of TC was transported into the intracellular and biodegraded. EPSs was extracted and the contents of polyprotein and polysaccharides reached their maximum values (30.84 mg/g and 11.15 mg/g) in the first four days. Fourier transform infrared spectroscopy analysis revealed that hydroxyl, methylidyne, methylene and amide I groups in EPSs participated in the adsorption of TC. Furthermore, three-dimensional excitation-emission matrix fluorescence spectroscopy analysis revealed that TC caused the quenching of EPSs fluorescent groups. The quenching mechanism was attributed to static quenching and protein-like substances in EPSs from Pandoraea sp. XY-2 dominated the TC adsorption process. Bioinformatic analysis of Pandoraea sp. XY-2 genome identified multiple genes involved in exopolysaccharide synthesis and EPSs formation. The insights gained in this study might provide a better understanding about the adsorption process of EPSs in tetracycline-contaminated environment.

Graphic abstract

中文翻译：

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潘多拉菌胞外聚合物的作用。XY-2中去除四环素。

摘要

在这项研究中，Pandoraea分泌的细胞外聚合物 ( EPSs ) 的作用sp. XY-2 在去除四环素 (TC) 方面进行了研究。早期溶液中的TC主要通过EPSs的吸附去除，占TC的20%。此后，大量的TC被转运到细胞内并被生物降解。EPSs 被提取，多蛋白和多糖的含量在前四天达到最大值（30.84 毫克/克和 11.15 毫克/克）。傅里叶变换红外光谱分析表明EPSs中的羟基、甲基、亚甲基和酰胺I基团参与了TC的吸附。此外，三维激发发射矩阵荧光光谱分析表明，TC 导致 EPSs 荧光基团的猝灭。猝灭机制归因于 EPSs 中的静态猝灭和蛋白质样物质潘多拉菌属 XY-2 主导了 TC 吸附过程。Pandoraea sp. 的生物信息学分析。XY-2 基因组鉴定了多个参与胞外多糖合成和 EPSs 形成的基因。本研究中获得的见解可能有助于更好地了解 EPSs 在四环素污染环境中的吸附过程。

图形摘要