The influence of biochar-released dissolved organic matter (BDOM) on the transcription of gene (DEG) in Pseudomonas stutzeri and Shewanella putrefacien during sulfamethoxazole (SMX) and chloramphenicol (CAP) biodegradation under visible light was investigated in this study. The results indicated that BDOM components would be nutrients for bacterial amplification and growth under the culture conditions of xenon lamp irradiation and avoiding light, especially BDOM from low temperatures. Additionally, visible light irradiation would improve the saturated fatty acid by stimulating the cell membrane of the microorganism, thus promoting the biodegradation of antibiotics through altering P. stutzeri and S. putrefaciens reoxidative and catabolism processes and significantly inhabiting the copy number of their genes. Moreover, the upregulated genes and enzymes related to SMX and CAP-metabolic and catabolic processes were enriched, which were involved in the pathways of biodegradation, further improving biodegradation efficiency. In particular, interaction network analysis between the top 100 dominant functional genes from P. stutzeri and S. putrefaciens and the molecular types of BDOM, e.g., CHO, CHON, and CHOS (p < 0.05), indicated that the genes of molecular function showed a high positive or negative correlation with the CHO type of BDOM. The results revealed that the CHO type of BDOM affected the functional genes of molecular function, cellular component, and biological process from P. stutzeri and S. putrefaciens, influencing the biodegradation of SMX and CAP. This study provided an basis for BDOM playing a role in antibiotic removal from the aqueous solution using biochar combined with photobiodegradation.

Graphical Abstract

中文翻译：

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生物炭衍生的溶解性有机物在可见光和避光交替条件下影响磺胺甲恶唑和氯霉素生物降解过程中的细菌特性

本研究调查了可见光下磺胺甲恶唑(SMX)和氯霉素 (CAP) 生物降解过程中生物炭释放的溶解有机物 (BDOM) 对施氏假单胞菌和腐败希瓦氏菌基因 (DEG) 转录的影响。结果表明，在氙灯照射和避光培养条件下，BDOM组分可能是细菌扩增和生长的营养物质，尤其是低温BDOM。此外，可见光照射会通过刺激微生物的细胞膜来提高饱和脂肪酸，从而通过改变P. stutzeri和S. putrefaciens来促进抗生素的生物降解。再氧化和分解代谢过程，并显着抑制其基因的拷贝数。此外，与SMX和CAP代谢和分解代谢过程相关的上调基因和酶得到丰富，参与生物降解途径，进一步提高生物降解效率。特别是，来自P. stutzeri和S. putrefaciens的前 100 个显性功能基因与 BDOM 的分子类型（例如 CHO、CHON 和 CHOS）之间的相互作用网络分析（p < 0.05)，表明分子功能基因与BDOM的CHO型呈高度正相关或负相关。结果表明，BDOM 的 CHO 型影响了P. stutzeri和S. putrefaciens的分子功能、细胞成分和生物学过程的功能基因，影响了 SMX 和 CAP 的生物降解。该研究为 BDOM 在使用生物炭结合光生物降解从水溶液中去除抗生素中发挥作用提供了基础。

图形概要