title: Effect of magnesium peroxide biostimulation of fish feed-loaded marine sediments on changes in the bacterial community.
abstract: The effect of an oxygen-releasing compound (ORC) magnesium peroxide (MgO(2)) on the changes in the bacterial community in organically polluted sediment of aquaculture farms was tested in a microcosm experiment. The sediment, to which fish feed was added, was treated with 1% or 5% MgO(2). The addition of fish feed induced a highly reduced environment with low redox potential, high total sulfides, and abundance of sulfate-reducing bacteria (SRB) . Although the sediment remained highly reduced at 1% MgO(2), there was a significant reduction of total sulfides, increase of redox potential, and resultant reduction of SRB. The bacterial community clearly changed with the treatments according to denaturing gradient gel electrophoresis (DGGE) analysis of 16S ribosomal RNA gene (16S rDNA) . Aerobes disappeared in the fish feed-added sediment, and some SRB emerged in place of these aerobes. On the other hand, the SRB disappeared in the ORC-amended sediment due to its highly oxic condition. This study revealed the bacterial community in the sediments was affected mainly by the redox potential and resultant sulfides produced by SRB, but total organic carbon and nitrogen were not determinants of the microbial population.
authors.affiliation: Department of Resource and Environmental Science of Agriculture, Forestry and Fisheries, the United Graduate School of Agricultural Sciences, Kagoshima University, Korimoto, Kagoshima, Japan.
authors.forename: Sheila Mae S
authors.initials: SM
authors.lastname: Santander-De Leon
authors.forename: Suguru
authors.initials: S
authors.lastname: Okunishi
authors.forename: Masaki
authors.initials: M
authors.lastname: Kihira
authors.forename: Miyo
authors.initials: M
authors.lastname: Nakano
authors.forename: Sharon N
authors.initials: SN
authors.lastname: Nuñal
authors.forename: Masayasu
authors.initials: M
authors.lastname: Hidaka
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Hiroto
authors.initials: H
authors.lastname: Maeda
mesh_terms: D000818:Animals; D017756:Aquaculture; D001419:Bacteria / Q000145:classification* / Q000235:genetics; D044822:Biodiversity; D017753:Ecosystem; D004777:Environment; D005399:Fishes; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology*; D017616:Magnesium Compounds / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013440:Sulfides / Q000737:chemistry
chemical_list: D017616:Magnesium Compounds; D010545:Peroxides; D012336:RNA, Ribosomal, 16S; D013440:Sulfides; C517394:magnesium peroxide