Dehalogenation Activities and Distribution of Reductive Dehalogenase Homologous Genes in Marine Subsurface Sediments†
Taiki Futagami,1,2 Yuki Morono,1 Takeshi Terada,3 Anna H. Kaksonen,4§ and Fumio Inagaki1*
Commonwealth Scientific and Industrial Research
Organization (CSIRO), Land and Water, Underwood Ave., Floreat, WA
Halogenated organic compounds serve as terminal electron acceptors for anaerobic respiration in a diverse
range of microorganisms. Here, we report on the widespread distribution and diversity of reductive dehalogenase
homologous (rdhA) genes in marine subsurface sediments. A total of 32 putative rdhA phylotypes were
detected in sediments from the southeast Pacific off Peru, the eastern equatorial Pacific, the Juan de Fuca
Ridge flank off Oregon, and the northwest Pacific off Japan, collected at a maximum depth of 358 m below the
seafloor. In addition, significant dehalogenation activity involving 2,4,6-tribromophenol and trichloroethene
was observed in sediment slurry from the Nankai Trough Forearc Basin. These results suggest that dehalorespiration
is an important energy-yielding pathway in the subseafloor microbial ecosystem.
Keywords: homologous (rdhA) genes, microorganisms,
ethenogenes strain,Aplysina aerophoba,bioremediation.
Corresponding author: Tel 81-88-878-2204; Fax 81-88-878-2192.