Tada Yuya, Marumoto Kohji, Iwamoto Yoko, Takeda Kazuhiko, Sakugawa Hiroshi
National Institute for Minamata Disease, Department of Environment and Public Health, Kumamoto, Japan.
National Institute for Minamata Disease, Department of Environment and Public Health, Kumamoto, Japan.
Mar Pollut Bull. 2023 Jan;186:114381. doi: 10.1016/j.marpolbul.2022.114381. Epub 2022 Nov 29.
Mercury (Hg) adversely affects human and environmental health. To evaluate the mercury (Hg) speciation (methylation, demethylation, and reduction) of microorganisms in coastal seawater, we analyzed the microbial functional gene sets involved in Hg methylation (hgcA and hgcB), demethylation (merB), and reduction (merA) using a metagenomic approach in the eastern and western parts (the Kii and Bungo channels, respectively) of the Seto Inland Sea (SIS) of Japan. We determined the concentration of dissolved total mercury (dTHg) and methylated mercury (dMeHg) in seawater. The metagenomic analysis detected hgcAB, merA, and merB in both channels, whereas the phylogenies of these genes differed between them. A correlation between Hg concentration (both dTHg and dMeHg) and the relative abundance of each gene was not observed. Our data suggests that microbial Hg methylation and demethylation could occur in the SIS and there could be a distinct microbial Hg speciation process between the Kii and Bungo channels.
汞（Hg）会对人类健康和环境产生不利影响。为了评估沿海水体中微生物的汞（Hg）形态（甲基化、去甲基化和还原），我们采用宏基因组学方法，分析了日本濑户内海（SIS）东部和西部（分别为纪伊水道和丰后水道）参与汞甲基化（hgcA和hgcB）、去甲基化（merB）和还原（merA）的微生物功能基因集。我们测定了海水中溶解态总汞（dTHg）和甲基汞（dMeHg）的浓度。宏基因组分析在两个水道中均检测到hgcAB、merA和merB，但这些基因的系统发育在两者之间存在差异。未观察到汞浓度（dTHg和dMeHg）与各基因相对丰度之间的相关性。我们的数据表明，濑户内海可能发生微生物汞甲基化和去甲基化，并且纪伊水道和丰后水道之间可能存在独特的微生物汞形态转化过程。
