广谱性多环芳烃降解真菌Aspergillus flavus AD-X-1的筛选及其性能研究

Screening and Characteristics of a Broad Spectrum Fungus Degrading Polycyclic-aromatic Hydrocarbons:Aspergillus flavus AD-X-1

筛选了一株具有广谱性多环芳烃的降解菌株,并研究了其降解特性,为复合污染治理提供了菌种保障和技术支持。以多环芳烃为唯一碳源和能源,筛选出1株多环芳烃高效降解菌,经鉴定为黄曲霉,命名为Aspergillus flavus AD-X-1。实验表明,该菌株AD-X-1对多环芳烃的去除以降解为主,菌丝体吸附也起到一定作用。以蒽为底物优化条件,蒽浓度为50 mg/L时,在温度35℃,转速170 r/min,pH值7时,72 h菌株AD-X-1对蒽的去除率可达到88%。研究发现该菌株有较好的耐受性,当盐度为9%时,菌株对蒽的去除率仍保持在50%,并且AD-X-1可耐受较高浓度的重金属离子(Cu^(2+)、Cr^(3+)和Pb^(2+))。除蒽、菲外,AD-X-1还可去除高环的芘、苯并蒽和二苯并蒽,去除率分别为71%、68%和63%。因此,菌株AD-X-1具有广谱的多环芳烃降解能力,同时具有很好的耐盐、耐重金属特性。

This study is aimed to screen a broad spectrum strain degrading polycyclic-aromatic hydrocarbons （ PAHs ） and investigate its degradation characteristics for providing strain supply and technical support in the management of combined pollution. An efficient PAHs- degradation fungus was screened with PAHs as the sole carbon and energy source and identified and designated as Aspergillusflavus AD-X-1. The experiment convinced that the degradation was predominant in the removal of PAHs by AD-X-1, while mycelium adsorption also played a part role. The degradation condition was optimized using anthracene as the substrate, and the removal rate of anthracene reached 88% in 72 h by AD-X-1 under the condition of 50 mg/L anthracene, temperature 35℃, rotator speed 170 r/min and pH 7. Further AD-X-1 was found to have promising salt-tolerance, and the removal rate of anthracene still remained at 50% when the salinity increased to 9%. Moreover, AD- X-ltolerated higher concentration of heavy metal ions （ Cr3＋, Cu2＋, and Pb2＋ ） . In addition to anthracene and phenanthrene, the removal rate of tetracyclic pyrene, benzo[ a ] anthracene, and dibenzo [ a, h ] anthracene by AD-X-1 were 71%, 68%, and 63% respectively. Conclusively, AD-X-1 has broad spectrum ability of removing PAHs, and concurrently it has the excellent resistances to salt and heavy metals.