title: Microbial responses using denaturing gradient gel electrophoresis to oil and chemical dispersant in enclosed ecosystems.
abstract: Microbial responses to the addition of oil with or without a chemical dispersant were examined in mesocosm and microcosm experiments by using denaturing gradient gel electrophoresis of bacterial ribosomal DNA and direct cell counting. When a water-soluble fraction of oil was added to seawater, increases in cell density were observed in the first 24h, followed by a decrease in abundance and a change in bacterial species composition. After addition of an oil-dispersant mixture, increases in cell density and changes in community structure coincided, and the amount of bacteria remained high. These phenomena also occurred in response to addition of only dispersant. Our results suggest that the chemical dispersant may be used as a nutrient source by some bacterial groups and may directly or indirectly prevent the growth of other bacterial groups.
authors.affiliation: Ocean Research Institute, The University of Tokyo, 1-15-1 Minamidai, Nakano-ku, Tokyo 164-8639, Japan. ayoshida@ori.u-tokyo.ac.jp
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yoshida
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nomura
authors.forename: Keita
authors.initials: K
authors.lastname: Toyoda
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Nishino
authors.forename: Yuna
authors.initials: Y
authors.lastname: Seo
authors.forename: Mihoko
authors.initials: M
authors.lastname: Yamada
authors.forename: Masahiko
authors.initials: M
authors.lastname: Nishimura
authors.forename: Minoru
authors.initials: M
authors.lastname: Wada
authors.forename: Ken
authors.initials: K
authors.lastname: Okamoto
authors.forename: Akira
authors.initials: A
authors.lastname: Shibata
authors.forename: Hideshige
authors.initials: H
authors.lastname: Takada
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kogure
authors.forename: Kouichi
authors.initials: K
authors.lastname: Ohwada
mesh_terms: D001419:Bacteria / Q000166:cytology / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development*; D001673:Biodegradation, Environmental / Q000187:drug effects; D017931:DNA Primers / Q000737:chemistry; D017753:Ecosystem; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods; D010232:Paraffin / Q000494:pharmacology; D010578:Petroleum; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D011156:Population Density; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000737:chemistry / Q000382:microbiology*; D012997:Solvents / Q000494:pharmacology; D013501:Surface-Active Agents / Q000494:pharmacology*; D013997:Time Factors; D014874:Water Pollutants, Chemical
chemical_list: D017931:DNA Primers; D010578:Petroleum; D012336:RNA, Ribosomal, 16S; D012997:Solvents; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D010232:Paraffin