Department of Microbiology, Sri Krishnadevaraya University, Anantapur-515 055, Andhra Pradesh, India.
J Microbiol Biotechnol. 2012 Nov;22(11):1540-8. doi: 10.4014/jmb.1112.12011.
Manganese peroxidase (MnP) was isolated from the culture filtrate of the wood log mushroom Stereum ostrea (S. ostrea), grown on Koroljova medium, and then purified by ammonium sulfate [70% (w/v)] fractionation, DEAE-cellulose anion exchange chromatography, and Sephadex G-100 column chromatography, with an attainment of 88.6-fold purification and the recovery of 22.8% of initial activity. According to SDS-PAGE the molecular mass of the MnP was 40 kDa. The optimal pH and temperature were found to be 4.5 and 35 degrees C, respectively. The enzyme was stable even after exposure to a pH range of 4.5 to 6.0, and at temperatures of up to 35 degrees C at a pH of 4.5 for 1h. The K(m) and V(max) values for the substrate phenol red were found to be 8 micronm and 111.14 U/mg of protein, respectively. The MnP also oxidized other substrates such as guaiacol, DMP, and veratryl alcohol. Sodium azide, EDTA, SDS, Cu(2+), and Fe(2+), at 1-5 mM, strongly inhibited enzyme activity, whereas Ca(2+) and Zn(2+) increased enzyme activity. The participation of the purified enzyme in the decolorization of dyes suggests that S. ostrea manganese peroxidase could be effectively employed in textile industries.
锰过氧化物酶 (MnP) 从在 Koroljova 培养基上生长的木蘑菇 Stereum ostrea（S. ostrea）的培养滤液中分离出来，然后通过硫酸铵 [70%（w/v）] 分级、DEAE-纤维素阴离子交换层析和 Sephadex G-100 柱层析进行纯化，达到 88.6 倍的纯化度和 22.8%的初始活性回收率。根据 SDS-PAGE，MnP 的分子量为 40 kDa。发现最佳 pH 值和温度分别为 4.5 和 35°C。即使在 pH 值为 4.5 至 6.0 的范围内，以及在 pH 值为 4.5 时温度高达 35°C 的情况下，该酶仍很稳定，1h 后仍保持稳定。发现底物酚红的 K(m) 和 V(max) 值分别为 8 µm 和 111.14 U/mg 蛋白。MnP 还氧化了其他底物，如愈创木酚、DMP 和藜芦醇。1-5 mM 的叠氮化钠、EDTA、SDS、Cu(2+)和 Fe(2+)强烈抑制酶活性，而 Ca(2+)和 Zn(2+)则增加酶活性。纯化酶在染料脱色中的参与表明，S. ostrea 锰过氧化物酶可有效用于纺织工业。
