title: Autochthonous bioaugmentation with environmental samples rich in hydrocarbonoclastic bacteria for bench-scale bioremediation of oily seawater and desert soil.
abstract: Oil-contaminated seawater and desert soil batches were bioaugmented with suspensions of pea (Pisum sativum) rhizosphere and soil with long history of oil pollution. Oil consumption was measured by gas-liquid chromatography. Hydrocarbonoclastic bacteria in the bioremediation batches were counted using a mineral medium with oil vapor as a sole carbon source and characterized by their 16S ribosomal RNA (rRNA)-gene sequences. Most of the oil was consumed during the first 2-4 months, and the oil-removal rate decreased or ceased thereafter due to nutrient and oxygen depletion. Supplying the batches with NaNO3 (nitrogen fertilization) at a late phase of bioremediation resulted in reenhanced oil consumption and bacterial growth. In the seawater batches bioaugmented with rhizospheric suspension, the autochthonous rhizospheric bacterial species Microbacterium oxidans and Rhodococcus spp. were established and contributed to oil-removal. The rhizosphere-bioaugmented soil batches selectively favored Arthrobacter nitroguajacolicus, Caulobacter segnis, and Ensifer adherens. In seawater batches bioaugmented with long-contaminated soil, the predominant oil-removing bacterium was the marine species Marinobacter hydrocarbonoclasticus. In soil batches on the other hand, the autochthonous inhabitants of the long-contaminated soil, Pseudomonas and Massilia species were established and contributed to oil removal. It was concluded that the use of rhizospheric bacteria for inoculating seawater and desert soil and of bacteria in long-contaminated soil for inoculating desert soil follows the concept of "autochthonous bioaugmentation." Inoculating seawater with bacteria in long-contaminated soil, on the other hand, merits the designation "allochthonous bioaugmentation."
authors.affiliation: Microbiology Program, Department of Biological Sciences, Faculty of Science, Kuwait University, PO Box 5969, Safat, 13060, Kuwait.
authors.forename: Nedaa
authors.initials: N
authors.lastname: Ali
authors.affiliation: Microbiology Program, Department of Biological Sciences, Faculty of Science, Kuwait University, PO Box 5969, Safat, 13060, Kuwait.
authors.forename: Narjes
authors.initials: N
authors.lastname: Dashti
authors.affiliation: Microbiology Program, Department of Biological Sciences, Faculty of Science, Kuwait University, PO Box 5969, Safat, 13060, Kuwait.
authors.forename: Samar
authors.initials: S
authors.lastname: Salamah
authors.affiliation: Microbiology Program, Department of Biological Sciences, Faculty of Science, Kuwait University, PO Box 5969, Safat, 13060, Kuwait.
authors.forename: Husain
authors.initials: H
authors.lastname: Al-Awadhi
authors.affiliation: Microbiology Program, Department of Biological Sciences, Faculty of Science, Kuwait University, PO Box 5969, Safat, 13060, Kuwait.
authors.forename: Naser
authors.initials: N
authors.lastname: Sorkhoh
authors.affiliation: Microbiology Program, Department of Biological Sciences, Faculty of Science, Kuwait University, PO Box 5969, Safat, 13060, Kuwait. samir.radwan@ku.edu.kw.
authors.forename: Samir
authors.initials: S
authors.lastname: Radwan
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D004783:Environmental Microbiology; D009821:Oils; D010578:Petroleum / Q000032:analysis; D059392:Petroleum Pollution; D011549:Pseudomonas / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere; D012623:Seawater / Q000737:chemistry* / Q000382:microbiology; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis; D014874:Water Pollutants, Chemical
chemical_list: D009821:Oils; D010578:Petroleum; D012336:RNA, Ribosomal, 16S; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical
keywords: Bioaugmentation; Bioremediation; Desert soil; Hydrocarbonoclastic bacteria; Oil-pollution; Seawater