Arsenic resistance in fungi conferred by extracellular bonding and vacuole-septa compartmentalization.
Arsenic resistance in fungi conferred by extracellular bonding and vacuole-septa compartmentalization.
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DOI：
10.1016/j.jhazmat.2020.123370
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发表时间：
2020-07
影响因子：
13.6
通讯作者：
Lijuan Li;X. Zeng;Paul N. Williams;Xin Gao;Lijuan Zhang;Junzheng Zhang;H. Shan;S. Su
中科院分区：
文献类型：
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作者：
Lijuan Li;X. Zeng;Paul N. Williams;Xin Gao;Lijuan Zhang;Junzheng Zhang;H. Shan;S. Su
微生物在砷的生态地球化学循环中起着重要作用，在环境解毒和生物修复方面具有巨大的潜力。外排、转化和区室化是微生物抗砷的关键过程。然而，细胞器特定的解毒和命运在细胞内转移和区室化还没有很好地理解。我们进行了一个时间过程实验（2-5天）的真菌菌株的细胞器分离，以探讨亚细胞As的分布。在10 mg L-1砷（As（V））胁迫下，真菌细胞器中As的积累顺序为细胞外（65%）>细胞壁（15%）>液泡（10%）>其它细胞器（8%）。液泡中的砷占原生质体总砷的55%.胞外结合和液泡区室化是供试菌株抗砷的主要机制。真菌原生质体中谷胱甘肽（GSH）的增加，作为一个合理的指标作为耐受性的反应。傅立叶变换红外光谱（FT-IR）表明，真菌细胞壁内的羧基和胺基可能与As结合，防止As流入。进一步用扫描透射X射线显微镜（STXM）分析发现，除了空泡外，真菌的隔膜也可以降解。
Microbes play a crucial role in arsenic (As) biogeochemical cycling and show great potential for environmental detoxification and bioremediation. Efflux, transformation, and compartmentalization are key processes in microbial As resistance. However, organelle specific As detoxification and fate during intracellular transfer and compartmentalization is not well understood. We conducted a time course experiment (2–5 days) of the organelle separation for fungal strains to explore subcellular As distributions. After exposure to 10 mg L−1of arsenate (As(V)), the As accumulation among fungal organelles was generally in the order of extracellular (65 %) > cell wall (15 %) > vacuole (10 %) > other organelles (8 %). The vacuole As accounted for 55 % of the protoplast As. Extracellular bonding and vacuole compartmentalization were the main mechanisms of As resistance in the fungal strains tested. Glutathione (GSH) increases in fungal protoplast in response to As toxicity, acting as a reasonable indicator of As tolerance. Fourier transform infrared (FT-IR) spectroscopy indicated that carboxyl and amines groups within fungal cell walls potentially bind with As preventing As influx. Further analysis using scanning transmission X-ray microscopy (STXM) identified that fungal septa besides vacuole could also immobilize As.