外生菌根真菌对五氯芬的耐受性及生理响应

在纯培养条件下,研究了7种外生菌根真菌--美昧牛肝菌(Boletus edulis)、铆钉菇(Gomphidius viscidus)、双色腊蘑(Laccaria bicolor)、褐疣柄牛肝菌(Leccinum 8cabrum)、红绒盖牛肝菌(Xerocomus chrysenteron)、大毒滑锈伞(Heboloma crustulinifoume)和长柄粘滑菇(Hebeloma longicaudum)在不同五氯酚浓度下的生长速度和耐受性,筛选出具有降解五氯酚潜力的3种外生菌根真菌--铆钉菇、双色腊蘑、褐疣柄牛肝菌;考察了这3种外生菌根真菌在五氯酚胁迫下的生长模式,并采用点试方法对真菌氧化还原酶的产生情况进行了检测.结果表明:低浓度(≤10mg·L-1)条件下,五氯酚并没有改变菌种的生长模式,其中铆钉菇表现出了对五氯酚较强的耐受性,而在较高浓度下(15mg·L-1),所有菌种生长均受到抑制.酶点试结果表明,铆钉菇是3种外生菌根真菌中氧化还原酶活性最强且种类较多的菌种,它表现出较高的漆酶、酪氨酸氧化酶和过氧化物酶活性,是一种具有高效降解芳环结构污染物潜力的菌根真菌.

Tolerance and physiological responses of ectomycorrhizal fungi to pentachloro-phenol

Seven species of ectomycorrhizal fungi, i.e. Boletus edulis, Gomphidius viscidus, Laccaria bicolor, Leccinum scabrum, Xerocomus chrysenteron, Heboloma crustuliniforme and Hebeloma longicaudum, were grown in media with different substrate concentrations of pentachlorophenol (PCP) to determine its effect on fungal growth. Due to their high potential for PCP degradation, Gomphidius viscidus, Laccaria bicolor and Leccinum scabrum may find future application in bioremediation of soils polluted by PCP. The mycelium biomass of these three ectomycorrhizal fungi were measured at different PCP concentrations and their enzymatic activity was assessed by spot tests. No impact on the growth of the mycelia was observed at low ambient PCP levels (less than or equal to 10 mg·L-1), however, at 15 mg·L-1, fungi growth was inhibited. Gomphidius viscidus had redoxases with the highest activity and largest diversity. The high activities of its polyphenol oxidases, laccase and peroxidase, even at high ambient PCP levels, makes Gomphidius viscidus the most promising fungus for bioremediation of PCP contaminated soil.