高耐砷真菌的分离及其耐砷能力

High arsenic-tolerant fungi:Their isolation and tolerant ability

从湖南石门县及郴州市重金属矿周边地区采集的6个砷污染土壤样品中,初步分离得到13株具有较强耐砷能力的真菌菌株,其中3株真菌的耐砷能力最强,经形态与分子鉴定分别为微紫青霉(Penicillin janthinellum)、尖孢镰刀菌(Fusarium oxysporum)和棘孢木霉(Tri-choderma asperellum).培养试验表明:微紫青霉、尖孢镰刀菌和棘孢木霉分别在30000mg·L-1、30000mg·L-1和20000mg·L-1的砷胁迫平板中表现出很好的菌落生长状况;在砷浓度分别为0～50、0～50和0～80mg·L-1的液态培养基中培养2d后,尖孢镰刀菌、棘孢木霉和微紫青霉的生物量均随砷浓度增加而增加,且在相应最高浓度(50、50、80mg·L-1)下的生物量显著高于不加砷的对照.此外,高浓度砷对该3株真菌的产孢能力没有影响.

A total of thirteen fungal strains with higher arsenic （As）-tolerance ability were isolated from six As-contaminated soil samples collected from the mining areas of Shimen County and Chenzhou City in Hunan Province. Among the strains isolated,Penicillin janthinellum,Fusarium oxysporum,and Trichoderma asperellum had the highest As-tolerance ability,based on the morphological identification and phylogenetic analysis. Culture experiment showed that on the solid plates with 30000,30000,and 20000 mg·L -1 of As,P. janthinellum,F. oxysporum,and T. asperellum had a better colony growth,and after cultured in the liquid medium with 0-50,0-50,and 0-80 mg ·L-1 of As for 2 days,respectively,the dry mycelia masses of the three strains all increased with increasing As concentration. When the As concentration reached 50,50,and 80 mg·L -1,respectively,the fungal biomass of F. oxysporum,T. asperellum,and P. janthinellum increased significantly,compared with CK. High concentration As had no significant effects on the sporalation of the three fungal strains.