Montiel-González A M, Fernández F J, Keer N, Tomasini A
Departamento de Biotecnología, CBS, Universidad Autónoma Metropolitana-Iztapalapa Avda, San Rafael Atlixco #186 Colonia Vicentina, Delegación Iztapalapa, 09340, México D.F., México.
Appl Microbiol Biotechnol. 2009 Aug;84(2):335-40. doi: 10.1007/s00253-009-1981-0. Epub 2009 Apr 2.
Fungal peroxidases and phenoloxidases are widely used in aromatic toxic compounds degradation. Peroxidases, such as lignin peroxidase and manganese peroxidase, as well as laccases are mainly produced by basidiomycetes and to a lower extent by other fungi, such as ascomycetes. Peroxidase-encoding genes have been described and homologous expression has been achieved in basidiomycetes. Heterologous expression has also been achieved in some non-producing peroxidase ascomycetes, like Penicillium and Aspergillus. In this work, heterologous expression of peroxidase-encoding genes, lignin peroxidase, and manganese peroxidase was achieved in a zygomycete producing only phenoloxidases (Amylomyces rouxii), aimed at coupling two different pathways used in nature for PCP removal in only one microbial strain. The ability of PCP removal was assayed with one of the obtained transformants, resulting in increased activity with respect to the ability of the parental strain cultured free of the inducer tyrosine (95% and 45%, respectively, of the initial PCP (12.5 mg L(-1)) in 120 h, or 100% and 49%, respectively, of the initial PCP after 144 h of liquid culture).
真菌过氧化物酶和酚氧化酶广泛应用于芳香族有毒化合物的降解。过氧化物酶，如木质素过氧化物酶和锰过氧化物酶，以及漆酶主要由担子菌产生，其他真菌如子囊菌产生的量较少。过氧化物酶编码基因已被描述，并且在担子菌中实现了同源表达。在一些不产生过氧化物酶的子囊菌如青霉和曲霉中也实现了异源表达。在这项工作中，在仅产生酚氧化酶的接合菌（鲁氏淀粉霉）中实现了过氧化物酶编码基因、木质素过氧化物酶和锰过氧化物酶的异源表达，目的是在单一微生物菌株中结合自然界中用于去除五氯苯酚的两种不同途径。用获得的一个转化体测定了五氯苯酚的去除能力，相对于在无诱导剂酪氨酸的情况下培养的亲本菌株的能力，活性有所提高（在120小时内分别为初始五氯苯酚（12.5 mg L(-1)）的95%和45%，或在液体培养144小时后分别为初始五氯苯酚的100%和49%）。
