Applied Microbiology Lab, Centre for Rural Development and Technology, Indian Institute of Technology Delhi, 110016, India.
Chemosphere. 2024 Jul;360:142370. doi: 10.1016/j.chemosphere.2024.142370. Epub 2024 May 17.
Decolorization of textile dyes and study of their intermediate compounds is necessary to comprehend the mechanism of dye degradation. In the present study, different fungal mediated solutions were explored to provide an alternative to treat the reactive dyes. Growing biomass of Pleurotus sajor caju showed 83% decolorization (249.99 mg L removal) of Reactive Blue 13 (RB 13) and 63% decolorization (188.83 mg L) of Reactive Black 5 (RB 5) at 300 mg L initial concentration on 8 d. Higher laccase activity was positively correlated with increase in decolorization. However, increasing dye concentration has inhibitory effect on fungal biomass due to increase in toxicity. In laccase mediated decolorization, laccase produced from P. sajor caju using carbon rich waste material as substrate showed 89% decolorization (276.36 mg L removal) of RB 13 and 33% decolorization (105.37 mg L removal) of RB 5 at 300 mg L initial dye concentration in 100 min at 30 °C and pH 3.0'. Comparing the two methods, laccase-mediated decolorization shows better decolorization in less time and does not produce sludge. Further, the present work also attempted to study the dye degradation pathway for Reactive blue 13 via laccase mediated process. Fourier-transform infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC), and gas chromatography-mass spectrometry (GC-MS) were utilized to identify the degraded products. The GC-MS analysis showed the formation of naphthalene, naphthalene 2-ol, benzene,1-2, dicarboxylic acid, 4, amino, 6,chloro, 1-3-5, triazin-2-ol as the final degraded products after enzymatic degradation of RB 13. These findings provide in-depth study of laccase-mediated textile dye degradation mechanism.
对纺织染料进行脱色处理并研究其中间化合物对于理解染料降解机制是必要的。在本研究中，探索了不同真菌介导的解决方案，以提供一种替代方法来处理活性染料。在 300mg/L 的初始浓度下，生长的姬松茸生物质对活性蓝 13（RB 13）的脱色率达到 83%（去除 249.99mg/L），对活性黑 5（RB 5）的脱色率达到 63%（去除 188.83mg/L），在 8 天内达到平衡。较高的漆酶活性与脱色率的增加呈正相关。然而，由于毒性增加，染料浓度的增加会对真菌生物量产生抑制作用。在漆酶介导的脱色过程中，使用富含碳的废物作为底物生产的漆酶对 RB 13 的脱色率达到 89%（去除 276.36mg/L），对 RB 5 的脱色率达到 33%（去除 105.37mg/L），在 30°C 和 pH 值 3.0 的条件下，在 100min 内达到初始染料浓度 300mg/L。与两种方法相比，漆酶介导的脱色在更短的时间内显示出更好的脱色效果，且不会产生污泥。此外，本工作还尝试通过漆酶介导的过程研究活性蓝 13 的染料降解途径。利用傅里叶变换红外光谱（FTIR）、高效液相色谱（HPLC）和气相色谱-质谱联用（GC-MS）来鉴定降解产物。GC-MS 分析表明，RB 13 经酶解后形成萘、萘 2-醇、苯、1,2,二羧酸、4,氨基、6,氯、1,3,5,三嗪-2-醇等最终降解产物。这些发现为深入研究漆酶介导的纺织染料降解机制提供了依据。
