Dariosh Yosefi - Academia.edu (original) (raw)
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International Journal of Engineering Research and Applications (IJERA)
North Carolina Agricultural and Technical State University
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Papers by Dariosh Yosefi
International Journal of Environmental Science & Technology, 2009
The ability of native bacteria to utilize diesel fuel as the sole carbon and energy source was in... more The ability of native bacteria to utilize diesel fuel as the sole carbon and energy source was investigated in this research. Ten bacterial strains were isolated from the oil refinery field in Tehran, Iran. Two biodegradation experiments were performed in low and high (500 and 10000 ppm, respectively) concentration of diesel fuel for 15 days. Only two isolates were able to efficiently degrade the petroleum hydrocarbons in the first test and degraded 86.67 % and, 80.60 % of diesel fuel, respectively. The secondary experiment was performed to investigate the toxicity effect of diesel fuel at high concentration (10000 ppm). Only one strain was capable to degrade 85.20 % of diesel fuel at the same time (15 days). Phenotype and phylogeny analysis of this strain was characterized and identified as dieseldegrading bacteria, based on gram staining, biochemical tests, 16S rRNA gene sequence analysis. These results indicate that this new strain was Bacillus sp. and could be considered as Bacillus Cereus with 98 % 16 S rRNA gene sequence similarity. The results indicate that native strains have great potential for in situ remediation of diesel-contaminated soils in oil refinery sites.
Environmental Health Engineering and Management
Background: Biosurfactants are valuable microbial products that have significant applications in ... more Background: Biosurfactants are valuable microbial products that have significant applications in various industries. The advantages of these compounds are biodegradability, low toxicity, activity in difficult environmental conditions, and the ability to produce oil residues and compounds from the surface of seawater and soils contaminated with oil compounds. The aim of this study was to evaluate the ability of biosurfactants production by Sporosarcina halophila. Methods: For this purpose, to detect the production of biosurfactant by Sporosarcina halophila, quantitative and qualitative screening methods such as hemolysis, oil spreading test and emulsification index test were used. Finally, different concentrations of crude oil in the bacterial growth medium were used to see that this strain can decompose crude oil using biosurfactant production to continue its growth or not. Results: The results showed that this strain is able to produce biosurfactants in oil hemolysis and spreading ...
International Journal of Environmental Science & Technology, 2009
The ability of native bacteria to utilize diesel fuel as the sole carbon and energy source was in... more The ability of native bacteria to utilize diesel fuel as the sole carbon and energy source was investigated in this research. Ten bacterial strains were isolated from the oil refinery field in Tehran, Iran. Two biodegradation experiments were performed in low and high (500 and 10000 ppm, respectively) concentration of diesel fuel for 15 days. Only two isolates were able to efficiently degrade the petroleum hydrocarbons in the first test and degraded 86.67 % and, 80.60 % of diesel fuel, respectively. The secondary experiment was performed to investigate the toxicity effect of diesel fuel at high concentration (10000 ppm). Only one strain was capable to degrade 85.20 % of diesel fuel at the same time (15 days). Phenotype and phylogeny analysis of this strain was characterized and identified as dieseldegrading bacteria, based on gram staining, biochemical tests, 16S rRNA gene sequence analysis. These results indicate that this new strain was Bacillus sp. and could be considered as Bacillus Cereus with 98 % 16 S rRNA gene sequence similarity. The results indicate that native strains have great potential for in situ remediation of diesel-contaminated soils in oil refinery sites.
Environmental Health Engineering and Management
Background: Biosurfactants are valuable microbial products that have significant applications in ... more Background: Biosurfactants are valuable microbial products that have significant applications in various industries. The advantages of these compounds are biodegradability, low toxicity, activity in difficult environmental conditions, and the ability to produce oil residues and compounds from the surface of seawater and soils contaminated with oil compounds. The aim of this study was to evaluate the ability of biosurfactants production by Sporosarcina halophila. Methods: For this purpose, to detect the production of biosurfactant by Sporosarcina halophila, quantitative and qualitative screening methods such as hemolysis, oil spreading test and emulsification index test were used. Finally, different concentrations of crude oil in the bacterial growth medium were used to see that this strain can decompose crude oil using biosurfactant production to continue its growth or not. Results: The results showed that this strain is able to produce biosurfactants in oil hemolysis and spreading ...