Behera Baishali, Kumari Neetu, Maruthi Mulaka, Singh R K, Saini J K
Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana 123029, India.
Department of Biochemistry, Central University of Haryana, Mahendergarh, Haryana 123029, India.
Bioresour Technol. 2025 Feb;417:131869. doi: 10.1016/j.biortech.2024.131869. Epub 2024 Nov 22.
The laccase from the newly isolated Trametes cubensis was investigated for its potential to degrade malachite green (MG) dye. Optimized solid-substrate fermentation enhanced laccase production by 8.8-fold, reaching an activity of 6577.0 ± 14.3 U/g. Proteomic characterization identified enzyme with 4 % sequence coverage, molecular weight of 43.1 kDa, and alignment with multicopper oxidases. Using one-factor-at-a-time optimization, MG decolorization was maximized at 89 % under optimal conditions: 20 U/mL enzyme dose, 0.1 mg/mL dye concentration, pH 5.0, and 2 h incubation at 50 °C. Crosslinking the laccase onto chitosan beads resulted in 82 % immobilization efficiency, with high recyclability and reusability, retaining over 52 % activity after 7 cycles and demonstrating similar (p < 0.05) dye degradation potential. MG degradation products exhibited significantly reduced phyto-, cyto-, and microbial toxicity. The degradation pathway was elucidated using gas chromatography-mass spectrometry analysis. Thus, both free and immobilized laccase from T. cubensis offer sustainable tool for effective MG degradation with reduced toxicity.
对新分离的古巴栓菌所产漆酶降解孔雀石绿（MG）染料的潜力进行了研究。优化的固体基质发酵使漆酶产量提高了8.8倍，活性达到6577.0±14.3 U/g。蛋白质组学表征鉴定出该酶的序列覆盖率为4%，分子量为43.1 kDa，与多铜氧化酶具有序列比对关系。采用单因素优化法，在最佳条件下（酶剂量20 U/mL、染料浓度0.1 mg/mL、pH 5.0、50℃孵育2 h），MG脱色率最高可达89%。将漆酶交联到壳聚糖珠上，固定化效率达82%，具有高可回收性和重复使用性，7个循环后仍保留超过52%的活性，并表现出相似的（p<0.05）染料降解潜力。MG降解产物的植物毒性、细胞毒性和微生物毒性显著降低。利用气相色谱-质谱分析阐明了降解途径。因此，古巴栓菌的游离漆酶和固定化漆酶都为有效降解MG且降低毒性提供了可持续的工具。
