Due to the multitude industrial applications of ligninolytic enzymes, their demands are increasing. Partial purification and intensive characterization of contemporary highly acidic laccase enzyme produced by an Egyptian local isolate designated Alcaligenes faecalis NYSO were studied in the present investigation. Alcaligenes faecalis NYSO laccase has been partially purified and intensively biochemically characterized. It was noticed that 40–60% ammonium sulfate saturation showed maximum activity. A protein band with an apparent molecular mass of ~ 50 kDa related to NYSO laccase was identified through SDS-PAGE and zymography. The partially purified enzyme exhibited maximum activity at 55 °C and pH suboptimal (2.5–5.0). Remarkable activation for enzyme activity was recognized after 10-min exposure to temperatures (T) 50, 60, and 70 °C; time elongation caused inactivation, where ~ 50% of activity was lost after a 7-h exposure to 60 °C. Some metal ions Cu2+, Zn2+, Co2+, Ni2+, Mn2+, Cd2+, Cr2+, and Mg2+ caused strong stimulation for enzyme activity, but Fe2+ and Hg2+ reduced the activity. One millimolar of chelating agents [ethylenediamine tetraacetic acid (EDTA), sodium citrate, and sodium oxalate] caused strong activation for enzyme activity. Sodium dodecyl sulfate (SDS), cysteine-HCl, dithiothreitol (DTT), β-mercaptoethanol, thioglycolic acid, and sodium azide caused strong inhibition for NYSO laccase activity even at low concentration. One millimolar of urea, imidazole, kojic acid, phenylmethylsulfonyl fluoride (PMSF), H2O2, and Triton X-100 caused activation. The partially purified NYSO laccase had decolorization activity towards different dyes such as congo red, crystal violet, methylene blue, fast green, basic fuchsin, bromophenol blue, malachite green, bromocresol purple eriochrome black T, and Coomassie Brilliant Blue R-250 with various degree of degradation. Also, it had a vast range of substrate specificity including lignin, but with high affinity towards p-anisidine. The promising properties of the newly studied laccase enzyme from Alcaligenes faecalis NYSO strain would support several industries such as textile, food, and paper and open the possibility for commercial use in water treatment. It will also open the door to new applications due to its ligninolytic properties in the near future.

中文翻译：

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粪便产碱杆菌的一种新型高酸性NYSO漆酶的部分纯化和生化特性

由于木质素分解酶在工业上的广泛应用，它们的需求正在增加。在本研究中，研究了由埃及当地分离株粪便Alcaligenes faecalis NYSO产生的当代高酸性漆酶的部分纯化和强化表征。产碱杆菌粪便NYSO漆酶已部分纯化，并经过深入的生化表征。注意到40-60％的硫酸铵饱和度显示出最大的活性。通过SDS-PAGE和酶谱法鉴定了与NYSO漆酶有关的表观分子量约为50 kDa的蛋白带。部分纯化的酶在55°C和最适pH（2.5–5.0）下显示最大活性。暴露于50、60和70°C（T）的温度10分钟后，酶活性得到了显着激活。时间延长导致失活，在60°C下暴露7小时后，约50％的活性丧失。某些金属离子Cu2 +，Zn2 +，Co2 +，Ni2 +，Mn2 +，Cd2 +，Cr2 +和Mg2 +强烈刺激了酶的活性，但Fe2 +和Hg2 +降低了酶活性。一毫摩尔的螯合剂[乙二胺四乙酸（EDTA），柠檬酸钠和草酸钠]引起了酶活性的强烈活化。十二烷基硫酸钠（SDS），半胱氨酸HCl，二硫苏糖醇（DTT），β-巯基乙醇，巯基乙醇酸和叠氮化钠即使在低浓度下也对NYSO漆酶活性产生强烈的抑制作用。一毫摩尔的尿素，咪唑，曲酸，苯甲基磺酰氟（PMSF），H2O2和Triton X-100引起活化。部分纯化的NYSO漆酶对不同的染料（如刚果红，结晶紫，亚甲基蓝，坚牢绿，碱性品红，溴酚蓝，孔雀石绿，溴甲酚紫铬铁黑T和考马斯亮蓝R-250，具有不同程度的降解。而且，它具有广泛的底物特异性，包括木质素，但对对茴香胺具有高亲和力。粪粪产碱菌（Alcaligenes faecalis）NYSO菌株新研究的漆酶具有广阔的前景，将为纺织，食品和造纸等多个行业提供支持，并为水处理的商业化应用提供了可能性。由于其木质素分解特性，它将在不久的将来打开新应用的大门。它具有广泛的底物特异性，包括木质素，但对对茴香胺具有高亲和力。粪粪产碱菌（Alcaligenes faecalis）NYSO菌株新研究的漆酶具有广阔的前景，将为纺织，食品和造纸等多个行业提供支持，并为水处理的商业化应用提供了可能性。由于其木质素分解特性，它将在不久的将来打开新应用的大门。它具有广泛的底物特异性，包括木质素，但对对茴香胺具有高亲和力。粪粪产碱菌（Alcaligenes faecalis）NYSO菌株新研究的漆酶具有广阔的前景，将为纺织，食品和造纸等行业提供支持，并为水处理的商业化应用提供了可能性。由于其木质素分解特性，它将在不久的将来打开新应用的大门。