| Pantoea sp.IMH介导土壤中砷锑的形态转化 |
| 摘要点击 2541 全文点击 1084 投稿时间：2017-01-13 修订日期：2017-04-05 |
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| 中文关键词 Pantoea sp.IMH 氧化还原转化 砷 锑 土壤 arsC |
| 英文关键词 Pantoea sp. IMH redox transformation arsenic antimony soil arsC |
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| 中文摘要 |
| 砷（As）、锑（Sb）污染是世界范围内比较严重的环境问题，且经常同时存在.微生物在As、Sb的氧化还原和迁移转化的过程中起着至关重要的作用.As和Sb作为同族元素，具有类似的化学性质和相关的微生物氧化还原机制.然而，砷还原菌株对As、Sb迁移转化机制的研究相对较少，特别是在As、Sb共存的土壤中.本研究的目的是探究含有arsC基因的砷还原菌株Pantoea sp.IMH对土壤中As、Sb的氧化还原和迁移转化.除了接种活细胞的活菌体系和非生物对照组，同时，考虑到自然界中细菌死亡裂解过程，还做了失活死细胞的死菌体系.结果表明，在活菌体系中，溶解态As（Ⅴ）有72.7 μg·L-1转化为As（Ⅲ），364.8 μg·L-1的溶解态的Sb（Ⅴ）没有还原，表明arsC介导的砷还原菌不能还原Sb（Ⅴ）.在死菌体系中，总砷和总锑的含量分别为506.8 μg·L-1、821.1 μg·L-1，是活菌体系（As=155.2 μg·L-1；Sb=364.8 μg·L-1）和非生物对照组中（As=57.6 μg·L-1；Sb=271.1 μg·L-1）砷锑含量的4倍左右.这可能是死菌体释放的胞内物质促进了砷锑的释放，3个体系中总砷和总锑释放量均显著性相关（P<0.05）.本研究进一步阐释了微生物对土壤中As和Sb迁移转化的影响. |
| 英文摘要 |
| Soil contamination with co-existing arsenic (As) and antimony (Sb) has become a serious environmental problem worldwide. Microorganisms play a dominant role in the redox transformation and mobilization of As and Sb. As and Sb belong to the same family; they are alike in nature and have related microbial oxidation-reduction mechanisms. However, limited knowledge is available about the impact of As-reducing bacteria on the fate of As and Sb in their co-existing soils. The purpose of this study was to explore the redox transformation and release of As and Sb in the presence of an arsC carrier, Pantoea sp. IMH, which has high As(Ⅴ)-reducing capability. In addition to the IMH incubation system, the dead cell system and abiotic control experiments were conducted. The results showed that the IMH incubation reduced all soluble As(Ⅴ) (72.7 μg·L-1) to As(Ⅲ) form, whereas soluble Sb(Ⅴ) (364.8 μg·L-1) was not reduced, indicating that the As (V)-reducing pathway mediated by arsC genesis was not able to reduce Sb(Ⅴ). The amounts of total As (506.8 μg·L-1) and total Sb (821.1 μg·L-1) in the dead cell system were approximately four times higher than in the living cell system (As=155.2 μg·L-1; Sb=364.8 μg·L-1) and the abiotic control (As=57.6 μg·L-1; Sb=271.1 μg·L-1) because of the biomolecules released from the dead cells which enhanced the release of As and Sb. The correlation analysis of dissolved As and Sb showed that the release of total As and Sb was correlated (P<0.05) in three systems. Our study shed new light on the impact of bacteria on the fate of As and Sb in soils. |
