Instituto de Química Física de los Materiales, Medio Ambiente y Energía, INQUIMAE, DQIAQF, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428EGA Buenos Aires, Argentina; Facultad de Ciencias, Universidad Nacional de Ingeniería, Av. Tupac Amaru 210, Lima 25, Perú.
Instituto de Química Física de los Materiales, Medio Ambiente y Energía, INQUIMAE, DQIAQF, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428EGA Buenos Aires, Argentina.
Ecotoxicol Environ Saf. 2021 Jul 1;217:112237. doi: 10.1016/j.ecoenv.2021.112237. Epub 2021 Apr 20.
Laccases and laccase-mediator systems (LMS) are versatile catalysts that can oxidize a broad range of substrates coupled to the sole reduction of dioxygen to water. They possess many biotechnological applications in paper, textile, and food industries, bioethanol production, organic synthesis, detection and degradation of pollutants, and biofuel cell development. In particular, bacterial laccases are getting relevance due to their activity in a wide range of pH and temperature and their robustness under harsh conditions. However, the enzyme and the redox mediator's availability and costs limit their large-scale commercial use. Here we demonstrate that β-(10-phenothiazyl)-propionic acid can be used as an efficient and low-cost redox mediator for decolorizing synthetic dyes by the recombinant laccase SilA from Streptomyces ipomoeae produced in E. coli. This new LMS can decolorize more than 80% indigo carmine and malachite green in 1 h at pH = 8.0 and 2 h in tap water (pH = 6.8). Furthermore, it decolorized more than 40% of anthraquinone dye remazol brilliant blue R and 80% of azo dye xylidine ponceau in 5 h at 50 °C, pH 8.0. It supported at least 3 decolorization cycles without losing activity, representing an attractive candidate for a cost-effective and environmentally friendly LMS functional at neutral to alkaline pH.
漆酶和漆酶-介体系统 (LMS) 是多功能催化剂，可氧化广泛的底物，同时将氧气唯一还原为水。它们在造纸、纺织和食品工业、生物乙醇生产、有机合成、污染物检测和降解以及生物燃料电池开发等领域具有许多生物技术应用。特别是，由于细菌漆酶在广泛的 pH 和温度范围内具有活性，并且在恶劣条件下具有稳健性，因此它们越来越受到关注。然而，酶和氧化还原介体的可用性和成本限制了它们的大规模商业用途。在这里，我们证明β-(10-吩噻嗪基)-丙酸可用作重组漆酶 SilA 的高效且低成本的氧化还原介体，SilA 来自于 Streptomyces ipomoeae，在大肠杆菌中生产。该新型 LMS 在 pH = 8.0 下 1 小时和自来水中（pH = 6.8）2 小时内可使超过 80%的靛蓝胭脂红和孔雀石绿褪色。此外，它在 50°C、pH 8.0 下 5 小时内可使超过 40%的蒽醌染料 Remazol 亮蓝 R 和 80%的偶氮染料二甲苯酚红褪色。它支持至少 3 次脱色循环而不会失去活性，是一种有吸引力的候选物，可用于在中性到碱性 pH 下具有成本效益和环保的 LMS 功能。
