Open AccessSubseafloor microbial communities associated with rapid turbidite deposition in the Gulf of Mexico continental slope (IODP Expedition 308)
Author(s) -
Nunoura Takuro,
Soffientino Bruno,
Blazejak Anna,
Kakuta Jungo,
Oida Hanako,
Schippers Axel,
Takai Ken
Publication year - 2009
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2009.00718.x
Subject(s) - sedimentary depositional environment , structural basin , sediment , turbidite , biology , geology , context (archaeology) , basement , microbial population biology , oceanography , ecology , paleontology , geography , archaeology , bacteria
The subseafloor microbial communities in the turbidite depositional basins Brazos‐Trinity Basin IV (BT Basin) and the Mars‐Ursa Basin (Ursa Basin) on the Gulf of Mexico continental slope (IODP holes U1319A, U1320A, U1322B and U1324B) were investigated by PCR‐dependent molecular analyses targeted to the small subunit (SSU) rRNA genes, dsrA and mcrA , and hydrogenase activity measurements. Biomass at both basins was very low, with the maximum cell or the SSU rRNA gene copy number <1 × 10 7 cells mL −1 or copies g −1 sediments, respectively. Hydrogenase activity correlated with biomass estimated by SSU rRNA gene copy number when all data sets were combined. We detected differences in the SSU rRNA gene community structures and SSU rRNA gene copy numbers between the basin‐fill and basement sediments in the BT Basin. Examination of microbial communities and hydrogenase activity in the context of geochemical and geophysical parameters and sediment depositional environments revealed that differences in microbial community composition between the basin‐fill and basement sediments in the BT Basin were associated with sedimentation regimes tied to the sea‐level change. This may also explain the distributions of relatively similar archaeal communities in the Ursa Basin sediments and basement sediments in the BT Basin.