一株甲基对硫磷降解菌——米曲霉JMUPMD-2的分离与鉴定

Isolation and identification of a parathion-methyl degrading fungus-Aspergillus oryzae JMUPMD-2

摘要:

对一株新分离的、能以甲基对硫磷为唯一磷源生长的菌株——JMUPMD-2利用形态观察和rDNA ITS序列分析对JMUPMD-2进行鉴定; 用气相色谱法检测培养过程中甲基对硫磷浓度的变化, 确定甲基对硫磷降解速率。该菌株的rDNA ITS序列与米曲霉 (Aspergillus oryzae)的同源性为99%, 菌落形态和显微形态都与米曲霉特征相符, 因此鉴定为米曲霉; 以350 μg/L甲基对硫磷为唯一磷源和350 μg/L甲基对硫磷及1 g/L K2HPO4组成的混合磷源分别培养该菌株, 200 h后的分解量分别为189 μg/L及28 μg/L。该菌株的胞内提取液具有明显的甲基对硫磷降解酶活性。

Abstract:

A newly isolated fungus JMUPMD-2, capable of growing with parathion-methyl as the sole phosphorus source, was identified based on morphological charaterisitics and rDNA ITS sequences analysis, and its capability of degrading parathion-methyl was investigated by determining the changes of parathion-methyl concentration in the broth of the isolate. JMUPMD-2’s colonic and microscopic morphologies were identical with and its sequences of rDNA ITS was 99% similar to Apspergillus oryzae. Consequently, it was identified as Aspergillus oryzae. When cultured with an artificial medium containing parathion-methyl as the sole phosphorus or parathion-methyl-K2HPO4 mixed phosphorus, concentration of parathion-methyl respectively reduced 189 μg/L and 28 μg/L after inoculating for 200 hours. JMUPMD-2’s intracellular extract had obvious parathion-methyl degrading enzyme activity.