Posgrado en Ciencias Biológicas, Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Carr. Tlaxcala-Puebla km 1.5, 90062, Tlaxcala, México.
Departamento de Biotecnología, CBS, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco #186, Colonia Vicentina, Delegación Iztapalapa, 09340, Ciudad de México, México.
Int Microbiol. 2022 Aug;25(3):495-502. doi: 10.1007/s10123-022-00238-9. Epub 2022 Feb 3.
Laccases are enzymes produced by plants and white rot fungi, such as Pleurotus ostreatus, with industrial applications. Fungal laccases have been widely studied, and investigations, such as those involving recombinant DNA technology or adding inducers, have been made to increase laccase production. On the other hand, it has been proposed that extracellular proteases could decrease laccase activity when both types of enzymes are produced by P. ostreatus. The aim of this work was to evaluate the effects of proteases on the activity of extracellular laccases produced by P. ostreatus PoB in submerged culture. Results showed that P. ostreatus PoB produced alkaline, acidic, and neutral proteases. Protease activity was quantified, and the highest activity at alkaline pH (9.0) was 5.63 IU/L (192 h), that at acidic pH (2.0) was 3.38 IU/L (192 h), and that at neutral pH (7.0) was 6.20 IU/L (312 h). The protease activity decreased in the presence of different protease inhibitors, as phenylmethylsulfonyl fluoride (PMSF), EDTA, pepstatin A, and a cocktail of protease inhibitors. Laccase activity was determined in cultures with and without protease inhibitors. In the control culture (without inhibitor), the highest laccase specific activity was 99.88 IU/mg protein. In cultures with PMSF, pepstatin A, or a cocktail of protease inhibitors, laccase activity increased by approximately 1.35-fold (138 IU/mg protein) with respect to the control culture. The inhibitor EDTA did not produce a positive effect on extracellular laccase activity. These results suggest that laccase activity is affected by the actions of acidic and neutral extracellular proteases.
漆酶是植物和白腐真菌（如糙皮侧耳）产生的酶，具有工业应用。真菌漆酶已得到广泛研究，并且已经进行了涉及重组 DNA 技术或添加诱导剂的研究，以增加漆酶的产量。另一方面，有人提出当糙皮侧耳同时产生细胞外蛋白酶和漆酶时，细胞外蛋白酶可能会降低漆酶的活性。本工作的目的是评估蛋白酶对糙皮侧耳 PoB 液体培养中产细胞外漆酶活性的影响。结果表明，糙皮侧耳 PoB 产生碱性、酸性和中性蛋白酶。测定了蛋白酶的活性，在碱性 pH（9.0）时的最高活性为 5.63IU/L（192 h），在酸性 pH（2.0）时的最高活性为 3.38IU/L（192 h），在中性 pH（7.0）时的最高活性为 6.20IU/L（312 h）。在不同蛋白酶抑制剂（如苯甲基磺酰氟（PMSF）、EDTA、胃蛋白酶抑制剂 A 和蛋白酶抑制剂混合物）存在的情况下，蛋白酶活性降低。在有和没有蛋白酶抑制剂的培养物中测定了漆酶活性。在对照培养物（无抑制剂）中，漆酶比活最高为 99.88IU/mg 蛋白。在含有 PMSF、胃蛋白酶抑制剂 A 或蛋白酶抑制剂混合物的培养物中，漆酶活性比对照培养物提高了约 1.35 倍（138IU/mg 蛋白）。抑制剂 EDTA 对细胞外漆酶活性没有产生积极影响。这些结果表明，漆酶活性受到酸性和中性细胞外蛋白酶的作用的影响。
