جستجوی مقالات مرتبط با کلیدواژه "محیط حداقل" در نشریات گروه "آب و خاک"

Oil contamination in Iran due to high application of oil compounds, is one of the most dangerous pollution factors. Bioremediation is a prime strategy for remediation, by which the pollutants can be removed by making use of microorganism or any biological process that employes microorganisms or their enzymes to rehabilitate the environment altered by the contaminants. With regards to the importance of this method, screening and isolation of oil-degrading bacteria from contaminated site of Bushehr province were done in Carbon Free Minimal Medium enriched by gas oil. In this study 19 isolates of bacteria (PDB 1-19) were isolated, and the molecular and kit identifications showed different genus and species such as Stenotrophomonas maltophilia, Ralstonia sp., Vibrio sp., Sphingobacterium sp., Zymomonas sp., Pseudomonas aeruginosa, Paracoccus sp., Pantoea sp., Achromobacter xylosoxidans, Acinetobacter johnsonii, Serattia odorifera, Pseudomonas alcaligenes, Entrobacter cloacae, Pseudomonas stutzeri and Chryseobacterium sp.. In order to determine the efficiency of these bacteria in hydrocarbondegradation an inoculum of pure culture of bacteria containing 108 cfu/ml was used in liquid assay, which was performed in factorial experiment based on completely randomized design with 2 replications. Utilization of hydrocarbon sources was again detected in CFMM broth supplemented with 2% gas oil where the growth turbidity (OD600nm) as an indicator for utilization of hydrocarbon and bacterial growth was measured at different times of 0, 48, 168, 216 and 312hr. Results showed that in CFMM broth assay all main factors including bacteria and time as well as their interaction were significant (p<0.01). These bacteria were effectively able to mineralize gas oil and among bacteria, best results was achieved by Chryseobacterium sp.. The ability of bacterial isolates for degradation of oil-compounds increased by increasing time of incubation.

Soil and water contamination by oil is one of the great environmental concerns. Bioremediation is one of principal strategies for remediation، wherein the pollutants can be removed by use of microorganism or any biological process that uses native or exogenous microorganisms. According to the positive role of Pseudomonas genus in bioremediation، in this study the potential of two Pseudomonad bacteria، including Peudomonas fluorescens CHAO، P. putida P13 and a non-Pseudomonad Pantoea agglomerans as hydrocarbon utilizing bacteria were estimated in presence of three compounds including gas oil (2%)، toluene (1%) and phenanthrene (0. 05%). Bacterial inoculum containing 108 cfu/ml was used in plate and liquid assays، which were performed in factorial experiment based on completely randomized design with three replications. Results showed that in CFMM plate assay، diameter of colony is not affected by any of bacterial isolates and compounds. In broth assay، P. putida P13 and P. fluorescence CHAO had similar behavior in the presence of Gas oil، toluene and phenanthrene and trend of bacterial growth was the same at different times، while with P. agglomerans P5 the lowest number of bacteria was achieved. Among three compounds the highest degradability was recorded to the gas oil، followed by phenanthrene and toluene. The ability of bacteria in degradation of oil-compounds increased by increasing time of incubation. To conclude، this study suggests the potential use of two Pseudomonas isolates for bioremediation of hydrocarbon-contaminated environments especially with aliphatic hydrocarbon.