关键词: 微生物降解, 藻毒素, 耦合工艺, 天然有机物

Abstract: Pteris vittata, as an arsenic (As) hyperaccumulator, can be colonized by arbuscular mycorrhizal (AM) fungi either in controlled conditions or at field sites. However, the physiological mechanisms of AM fungi affecting the As accumulation and translocation in P. vittata are not fully elucidated. In this study, two isolates of Glomus mosseae were obtained from the rhizosphere of P. vittata growing on an Ascontaminated site in Jinchuantang of Hunan Province (G. mosseae BGC GD01A, metalcontaminated isolate) and from the clean soil in Yunnan Province (G. mosseae BGC YN05, uncontaminated isolate). The isolates were inoculated to the rhizosphere of Ascontaminated and uncontaminated P. vittata, respectively. After 8 weeks of inoculation, a 24h water culture experiment was conducted with the P. vittata seedlings colonized by AM fungi and exposed to 100 μmol·L^-1 of As (Na₂HAsO₄·7H₂O). Both the two isolates could colonize on P. vittata roots at moderate level (25.2%-31.3%). The inoculation either with metalcontaminated isolate or with uncontaminated isolate promoted the P uptake by P. vittata roots obviously. During the 24 h culture, the inoculation with uncontaminated isolate promoted the As uptake by P. vittata roots significantly, while the inoculation with metalcontaminated isolate only had a slight effect in promoting the As uptake, showing that there was an intraspecific difference of AM fungi in their effects on the As uptake by P. vittata.

Key words: cyanobacterial toxin, coupling process, microbial degradation, natural organic matter.