3-苯氧基苯甲酸降解真菌的筛选及其降解特性

Isolation and Identification of a 3-Phenoxybenzoic Acid-Degrading Fungus and Its Degradation Characteristics

以传统发酵食品为菌源,经不同质量浓度3-苯氧基苯甲酸(3-PBA)梯度驯化,筛选出6株具有3-PBA降解能力的霉菌,其中从砖茶中分离的降解菌YAT1可在22h内完全降解PD培养基中100mg/L的3-PBA,根据其形态特征和ITS序列分析(GenBank Accession No.JQ366070),将其鉴定为黑曲霉(Aspergillus niger)。动力学研究表明,YAT1降解3-PBA的过程符合一级动力学方程,在测试的底物(3-PBA)质量浓度、温度、pH值范围内,3-PBA半衰期为5.635～12.160h,远远低于其自然降解半衰期(180d),且该反应的速率受pH值影响不大,受底物质量浓度和温度的影响较大。

Six mould strains capable of degrading 3-phenoxybenzoic acid （3-PBA） were screened from traditional fermented foods following gradient acclimation by different concentration of 3-PBA. Among these strains, YAT1 isolated from black tea could completely degrade 100 mg/L 3-PBA in PD medium in 22 h. Based on its morphological characteristics and ITS sequences （GenBank Accession No. JQ366070）, YAT1 was identified as Aspergillus niger. Kinetic research indicated that the degradation of 3-PBA by YAT1 could be described by a first-order kinetics model. The degradation half-life of 3-PBA ranged from 5.635 to 12.160 h, which was far below its natural degradation half-life （180 d）, and the reaction was less affected by pH but significantly influenced by substrate concentration and temperature.