Arsenic speciation transformation and arsenite influx and efflux across the cell membrane of fungi investigated using HPLC–HG–AFS and in-situ XANES. (January 2015)

• Record Type: Journal Article
• Authors: Zeng, Xibai; Su, Shiming; Feng, Qiufen; Wang, Xiurong; Zhang, Yangzhu; Zhang, Lili; Jiang, Sheng; Li, Aiguo; Li, Lianfang; Wang, Yanan; Wu, Cuixia; Bai, Lingyu; Duan, Ran
• Is Part Of: Chemosphere. Volume 119(2015)
• Page Start: 1163
• Page End: 1168
• Publication Date: 2015-01
• Subjects: Arsenite -- Fungi -- Speciation transformation -- De-toxicity -- XANES; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2014.10.034
• Languages: English
• ISSNs: 0045-6535

Abstract

Highlights: As(III) can enter into fungal cells and some of which can be exuded out of cells. As(III) in fungal cells can be oxidized/methylated with As(V)/MMA, DMA as products. As(III) is the dominated specie of As sequestrated into fungal cytoplasm. As(III) is the dominant specie of As adsorbed onto the cell walls of fungi. Abstract: 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 of Trichoderma asperellum SM-12F1, Penicillium janthinellum SM-12F4, and Fusarium oxysporum CZ-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 of T . asperellum SM-12F1, P . janthinellum SM-12F4, and F . oxysporum CZ-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). For T . asperellum SM-12F1, the proportion (%) of MMA was 31.1%, and no As(V) or DMA was detected. For F . oxysporum CZ-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 the P . janthinellum SM-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.