title: Effect of nickel on the mineralization of hydrocarbons by indigenous microbiota in Kuwait soils.
abstract: Assessment of nickel contents in soil samples in Kuwait indicated only a minor difference in concentration in hydrocarbon-contaminated (86 mg kg(-1) soil) and non-contaminated soils (84 mg kg(-1) soil). The potential inhibitory effects of nickel on the number of hydrocarbon degraders, and hydrocarbon utilization were investigated over a wide range of nickel concentrations to span concentrations observed in the soil. Nickel addition, as nickel sulphate, to soil samples reduced the number of hydrocarbon degraders in all samples by a wide range (15-96%) depending on concentration and the hydrocarbon substrate utilized. Similarly, the metabolic activities were affected as observed in mineralization (3-60%) of soils amended with various concentrations of nickel. The inhibitive effects of nickel on hexadecane and crude oil utilization were minimal but were significantly higher with naphthalene (P < 0.05) in both hydrocarbon-contaminated and non-contaminated soils. Polarographic determination of hydrocarbons induced oxygen uptake rate demonstrated the tendency of nickel to significantly inhibit (P < 0.05) the oxidation of polyaromatic hydrocarbons compared to aliphatic hydrocarbons.
authors.affiliation: Microbiology Program, Department of Biological Sciences, Safat, College of Science, Kuwait University, State of Kuwait. Keva5000@hotmail.com
authors.forename: Esmaeil S
authors.initials: ES
authors.lastname: Al-Saleh
authors.forename: Christian
authors.initials: C
authors.lastname: Obuekwe
mesh_terms: D000473:Alkanes / Q000378:metabolism; D001419:Bacteria / Q000302:isolation & purification / Q000378:metabolism; D001673:Biodegradation, Environmental; D006838:Hydrocarbons / Q000378:metabolism*; D007730:Kuwait; D009281:Naphthalenes / Q000378:metabolism; D009532:Nickel / Q000378:metabolism*; D010578:Petroleum / Q000378:metabolism; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D000473:Alkanes; D006838:Hydrocarbons; D009281:Naphthalenes; D010578:Petroleum; D012989:Soil Pollutants; C031721:naphthalene; C029938:nickel sulfate; D009532:Nickel; C007932:n-hexadecane