Department of Biotechnology, Indian Institute of Technology, Roorkee, Uttarakhand, 24667, India.
Department of Biotechnology, Indian Institute of Technology, Roorkee, Uttarakhand, 24667, India.
Chemosphere. 2021 Jun;273:129671. doi: 10.1016/j.chemosphere.2021.129671. Epub 2021 Jan 19.
The present work focuses on studying the degradation of industrial synthetic dyes, which poses serious health hazards and a drastic impact on the environment. Currently available enzymatic processes have higher production and operational costs. However, most enzymes are active at acidic pH, which limits its application in textile dye degradation. This problem can be overcome by lignolytic enzymes obtained from halo-alkaliphile through Solid State Fermentation (SSF) using wheat bran (agro-byproduct) as a substrate. The major lignolytic enzymes studied were Lignin Peroxidase (LiP), Manganese Peroxidase (MnP), and laccase. The results demonstrated the highest activity of 215.4 ± 1.57 of LiP, 36.8 ± 2.38 of MnP, and 8.34 ± 0.21 IU/gds of laccase. Crude enzymes were used to treat synthetic dyes (mainly azo dyes), and their potential for its degradation was confirmed by spectrophotometric, GC-MS, and HPLC analysis. The highest decolorization of 82-93% of Malachite Green (MG) was achieved in LiP and MnP mediated reaction system within 2 hours. The laccase reaction system showed degradation of 53.87% of methyl orange without adding any redox mediator. After obtaining these results, the crude LiP and MnP in the reaction system were further subjected to decolorization at a higher MG concentration of 100-600 mg/L without a redox mediator. As a result, both LiP and MnP decolorized MG by 72-89%. Further, GC-MS analysis of MG biodegradation products confirmed the formation of less toxic low molecular weight products such as benzaldehyde and methanone.
本工作主要研究工业合成染料的降解，这些染料对健康危害严重，对环境影响巨大。目前可用的酶法工艺生产成本和运营成本都较高。然而，大多数酶在酸性 pH 下具有活性，这限制了其在纺织染料降解中的应用。这个问题可以通过使用麦麸（农业副产物）作为底物的固态发酵（SSF）从耐盐嗜碱菌中获得木质素降解酶来克服。研究的主要木质素降解酶有木质素过氧化物酶（LiP）、锰过氧化物酶（MnP）和漆酶。结果表明，LiP 的最高活性为 215.4±1.57，MnP 的最高活性为 36.8±2.38，漆酶的最高活性为 8.34±0.21 IU/gds。粗酶用于处理合成染料（主要是偶氮染料），通过分光光度法、GC-MS 和 HPLC 分析证实了其潜在的降解能力。LiP 和 MnP 介导的反应体系在 2 小时内实现了孔雀石绿（MG）高达 82-93%的脱色率。漆酶反应体系在不添加任何氧化还原介体的情况下，对甲基橙的降解率达到 53.87%。在获得这些结果后，在更高的 MG 浓度（100-600mg/L）下，反应体系中的粗 LiP 和 MnP 进一步进行了脱色，而无需添加氧化还原介体。结果，LiP 和 MnP 使 MG 脱色率达到 72-89%。此外，MG 生物降解产物的 GC-MS 分析证实了形成了毒性较低的低分子量产物，如苯甲醛和甲酮。
