de la Rubia Teresa, Linares Araceli, Pérez Juana, Muñoz-Dorado José, Romera José, Martínez José
Departamento de Microbiología, Facultad de Farmacia, Universidad de Granada, Spain.
Res Microbiol. 2002 Oct;153(8):547-54. doi: 10.1016/s0923-2508(02)01357-8.
Phanerochaete flavido-alba is able to decolorize and detoxify olive oil wastewater (OMW) in a process in which simple and polymeric phenols are removed. An unusual acidic MnP is accumulated during the degradation course. This microorganism produces two families of MnPs. MnP1 has an apparent molecular weight of 45 kDa and is secreted as a mixture of isoenzymes with pI ranging from 5.6 to 4.75. MnP2, which is produced as an unique isoenzyme, has an apparent molecular weight of 55.6 Mr and an unusual acidic pI lower than 2.8. The higher specific peroxidase activity for purified MnP2 was for Mn2+ oxidation. Hydroquinone and methylhydroquinone oxidation by MnP2 was Mn2+ dependent, in reaction mixtures without exogenous H2O2. Conversely, ABTS oxidation was Mn2+ independent. Two different DNA fragments (mnpA and mnpB), amplified by PCR, using MnP2 N-terminal sequence and oligonucleotides deduced from two conserved sequences of other MnPs, code for MnPs that belong to the P. chrysosporium mnp2 subfamily on the basis of intron position. The structure of mnpA and mnpB seems to be related to known manganese peroxidase genes, but mnpA encodes an Alanine instead of a Serine (Ser168) regarded as invariant within typical MnPs.
黄白拟层孔菌能够在去除简单酚类和聚合酚类的过程中使橄榄油废水（OMW）脱色并解毒。在降解过程中会积累一种不寻常的酸性锰过氧化物酶（MnP）。这种微生物产生两类MnP。MnP1的表观分子量为45 kDa，以等电点范围为5.6至4.75的同工酶混合物形式分泌。MnP2作为一种独特的同工酶产生，表观分子量为55.6 kDa，其不寻常的酸性等电点低于2.8。纯化后的MnP2对Mn2+氧化具有更高的比过氧化物酶活性。在没有外源H2O2的反应混合物中，MnP2对氢醌和甲基氢醌的氧化依赖于Mn2+。相反，ABTS的氧化不依赖于Mn2+。使用MnP2的N端序列和从其他MnP的两个保守序列推导的寡核苷酸通过PCR扩增出两个不同的DNA片段（mnpA和mnpB），根据内含子位置，它们编码的MnP属于黄孢原毛平革菌mnp2亚家族。mnpA和mnpB的结构似乎与已知的锰过氧化物酶基因有关，但mnpA编码的是丙氨酸而不是典型MnP中被视为不变的丝氨酸（Ser168）。
