In this study, the biological decolorization of reactive black 5 (RB5) by Klebsiella sp. KL-1 in yeast extract (YE) medium was captured the recolorization after exposure to O₂, which induced a 15.82% reduction in decolorization efficiency. Similar result was also observed in YE+lactose medium, but not in YE+glucose/xylose media (groups YE+Glu/Xyl). Through biodegradation studies, several degradation intermediates without quinoid structure were produced in groups YE+Glu/Xyl and differential degradation pathways were deduced in diverse groups. Metabolomics analysis revealed significant variations in up-/down-regulated metabolites using RB5 and different carbon sources. Moreover, the underlying mechanism of recolorization inhibition was proposed. Elevated reducing power associated with variable metabolites (2-hydroxyhexadecanoic acid, 9(R)-HODE cholesteryl ester, linoleamide, oleamide) rendered additional reductive cleavage of C-N bond on naphthalene ring. This study provided a new orientation to inhibit recolorization and deepened the understanding of the molecular mechanism of carbon sources inhibiting recolorization in the removal of refractory dyes.

在这项研究中，Klebsiella sp。对活性黑5（RB5）的生物脱色。暴露于O ₂后，酵母提取物（YE）培养基中的KL-1被捕获并重新着色，导致脱色效率降低15.82％。在YE +乳糖培养基中也观察到了相似的结果，但在YE +葡萄糖/木糖培养基（YE + Glu / Xyl组）中未观察到类似的结果。通过生物降解研究，在YE + Glu / Xyl组中生产了几种没有醌型结构的降解中间体，并在不同组中推导了不同的降解途径。代谢组学分析显示，使用RB5和不同碳源的上/下调代谢产物存在显着差异。此外，提出了抑制变色的潜在机理。与可变代谢物（2-羟基十六烷酸9（R）-HODE胆固醇酯，亚油酰胺，油酰胺）可进一步还原萘环上的CN键。这项研究为抑制再着色提供了新的方向，并加深了对碳源抑制难降解染料去除中再着色的分子机理的理解。