Bacteria mediate methylation of iodine in marine and terrestrial environments.
Methyl iodide (CH(3)I) plays an important role in the natural iodine cycle and participates in atmospheric ozone destruction. However, the main source of this compound in nature is still unclear. Here we report that a wide variety of bacteria including terrestrial and marine bacteria are capable of methylating the environmental level of iodide (0.1 microM). Of the strains tested, Rhizobium sp. strain MRCD 19 was chosen for further analysis, and it was found that the cell extract catalyzed the methylation of iodide with S-adenosyl-L-methionine as the methyl donor. These results strongly indicate that bacteria contribute to iodine transfer from the terrestrial and marine ecosystems into the atmosphere.
Amachi
S
S
National Institute of Bioscience and Human Technology, Agency of Industrial Science and Technology, Tsukuba, Ibaraki 305-8566, Japan.
Kamagata
Y
Y
Kanagawa
T
T
Muramatsu
Y
Y
D001419:Bacteria / Q000378:metabolism*; D004783:Environmental Microbiology; D005618:Fresh Water; D006847:Hydrocarbons, Iodinated / Q000378:metabolism*; D007454:Iodides / Q000378:metabolism*; D007455:Iodine / Q000378:metabolism*; D008386:Marine Biology; D008745:Methylation; D012231:Rhizobium / Q000378:metabolism; D012436:S-Adenosylmethionine / Q000378:metabolism; D014871:Water Microbiology
D006847:Hydrocarbons, Iodinated; D007454:Iodides; D012436:S-Adenosylmethionine; D007455:Iodine; C014055:methyl iodide