Arsenic speciation transformation and arsenite influx and efflux across the cell membrane of fungi investigated using HPLC-HG-AFS and in-situ XANES.
Arsenic speciation transformation and arsenite influx and efflux across the cell membrane of fungi investigated using HPLC-HG-AFS and in-situ XANES.
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DOI：
10.1016/j.chemosphere.2014.10.034
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发表时间：
2015
期刊：
影响因子：
8.8
通讯作者：
X. Zeng;S. Su;Q. Feng;Xiurong Wang;Yang Zhang;Lili Zhang;Sheng Jiang;Aiguo Li;Lianfang Li
中科院分区：
文献类型：
--
作者：
X. Zeng;S. Su;Q. Feng;Xiurong Wang;Yang Zhang;Lili Zhang;Sheng Jiang;Aiguo Li;Lianfang Li
微生物对砷的形态控制在砷的生态地球化学循环中起着重要作用。本研究采用细胞裂解-色谱分离方法，结合原位X射线吸收近边结构（XANES）分析，研究了As（III）在Asperellum木霉SM-12 F1、微黄青霉SM-12 F4和尖孢镰刀菌CZ-8 F1细胞膜上的形态转化和As（III）的内流和外流。结果表明，As（III）可以进入真菌细胞，一部分As（III）可以渗出细胞。无论是螯合到真菌细胞质和As吸附到细胞壁上，As（III）被发现是占主导地位的形式。XANES分析显示，As（III）分别占T. asperellum SM-12 F1、P. janthinellum SM-12 F4和F. oxysporum CZ-8 F1细胞中总As的58.4%、59.5%和73.0%。然而，在这些真菌菌株中，有明显的差异，在砷酸盐[As（V）]，单甲基胂酸（MMA），二甲基胂酸（DMA）的相对比例。棘球绦虫SM-12 F1的MMA含量为31.1%，未检出As（V）和DMA。尖孢镰刀菌CZ-8 F1中As（V）和MMA的含量分别为15.8%和8.8%，没有发现DMA。As（V）、MMA和DMA分别占紫球藻SM-12 F4细胞的4.2%、29.5%和8.1%。一些细胞内的As（III）可以被这些真菌菌株氧化和甲基化，并产生As（V）、MMA和DMA作为产物。
Microorganisms dominated speciation of arsenic (As) play an important role in the biogeochemical cycling of As. In the study, species transformation of arsenite [As(III)] and As(III) influx and efflux across the cell membranes ofTrichoderma asperellumSM-12F1,Penicillium janthinellumSM-12F4, andFusarium oxysporumCZ-8F1 cells were studied using a cellular lysis plus chromatographic separation method and further the in-situ X-ray absorption near edge structure (XANES) analysis. The results indicated that As(III) can enter into fungal cells and that a portion of the As(III) can be exuded out of cells. For both As sequestrated into fungal cytoplasm and As adsorbtion onto cell walls, As(III) was found to be the dominated form of As. XANES analysis showed that As(III) accounted for 58.4%, 59.5%, and 73.0% of the total As in the cells ofT.asperellumSM-12F1,P.janthinellumSM-12F4, andF.oxysporumCZ-8F1, respectively. Among these fungal strains, however, there were obvious differences in the relative proportions of arsenate [As(V)], monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). ForT.asperellumSM-12F1, the proportion (%) of MMA was 31.1%, and no As(V) or DMA was detected. ForF.oxysporumCZ-8F1, the proportions of As(V) and MMA were 15.8% and 8.8%, respectively, but no DMA was observed. As(V), MMA, and DMA accounted for 4.2%, 29.5%, and 8.1%, respectively, of theP.janthinellumSM-12F4 cells. Some of the intracellular As(III) can be oxidated and methylated by these fungal strains and yield As(V), MMA, and DMA as products.