北京大学学报自然科学版 ›› 2019, Vol. 55 ›› Issue (4): 709-716.DOI: 10.13209/j.0479-8023.2019.047

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两种赤潮藻对汞富集和甲基化影响的研究

陶虎春†, 阳赛, 丁凌云, 张丽娟, 何宁宁, 张曜宇   

  1. 深圳市重金属污染控制与资源化重点实验室, 北京大学深圳研究生院环境与能源学院, 深圳 518055
  • 收稿日期:2018-05-02 修回日期:2019-04-19 出版日期:2019-07-20 发布日期:2019-07-20
  • 通讯作者: 陶虎春, E-mail: taohc(at)pkusz.edu.cn
  • 基金资助:
    国家自然科学基金(51679002)、深圳市基础研究项目(JCYJ20180503182122539, JCYJ20160330095549229)和流域生态工程学学科建设资金(深发改[2017]542 号)资助

Study on the Effect of Two Red-Tide Algae on Mercury Biocondensation and Methylation

TAO Huchun†, YANG Sai, DING Lingyun, ZHANG Lijuan, HE Ningning, ZHANG Yaoyu   

  1. Shenzhen Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055
  • Received:2018-05-02 Revised:2019-04-19 Online:2019-07-20 Published:2019-07-20
  • Contact: Tao Huchun, E-mail: taohc(at)pkusz.edu.cn

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摘要：

研究塔玛亚历山大藻(Alexandrium tamarens)和锥状斯式藻(Scrippsiella trochoidea)两种赤潮藻对海水中汞的富集和甲基化的影响, 探讨赤潮藻对硫铁还原地杆菌 Geobacter sulfurreducens PCA (G. sulfurreducens PCA)汞生物甲基化的抑制作用。实验结果表明, 不同种类藻对汞的耐受性不同, 高浓度HgCl2 (≥25 μg/L)抑制锥状斯式藻的生长, 而对塔玛亚历山大藻的影响较小。两种藻均可有效地富集无机汞, 但直接进行汞甲基化的效果不显著。FTIR分析发现, 藻细胞表面分泌的大量羧基、氨基和羟基等官能团是富集汞的主要位点。汞-藻-菌实验中, 当HgCl2初始浓度为10 ug/L时, G. sulfurreducens PCA驱动的汞生物甲基化效率可达 (6.38±0.4)%, 在G. sulfurreducens PCA与塔玛亚历山大藻共存的实验组中, 汞甲基化效率为 (1.04±0.44)%, G. sulfurreducens PCA与锥状斯式藻的实验组中汞甲基化效率低至 (0.76±0.05)%, 两种赤潮藻的加入抑制了G. sulfurreducens PCA的汞生物甲基化。

关键词: 汞, 甲基化, 锥状斯式藻, 塔玛亚历山大藻, 硫铁还原地杆菌PCA

Abstract:

The effect of two red-tide algae of Alexandrium tamarens and Scrippsiella trochoidea on mercury (Hg) adsorption and methylation were investigated. The inhibitory effect of two algae on biomethylation of Geobacter Sulfurreducens (G. sulfurreducens) PCA were demonstrated. The growth of Scrippsiella trochoidea was inhibited under exposure to high concentration of HgCl2 (≥25 μg/L), but less affecting Alexandrium tamarens. Significant adsorption of Hg2+ was observed onto algal cells, whilst negligible amount of methylmercury (MeHg) was produced by two algae directly. FTIR spectra revealed that hydroxyl, carboxyl and amino groups were major binding sites for Hg2+ adsorption. In Hg-algae-bacteria tests, at initial HgCl2 concentration of 10 μg/L, a maximum mercury methylation efficiency of (6.38±0.4)% was obtained by pure G. sulfurreducens PCA culture as a control, but the efficiency reduced to (1.04±0.44)% with G. sulfurreducens PCA and Alexandrium tamarens coexisting, and a much lower efficiency of (0.76±0.05)% was detected with G. sulfurreducens PCA and Scrippsiella trochoidea coexisting. These results suggested that two red-tide algae inhibited mercury biomethylation of G. sulfurreducens PCA.

Key words: mercury, methylation, Scrippsiella trochoidea, Alexandrium tamarens, Geobactersul furreducens PCA

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