Molecular detection of biodegradation and biosurfactant-producing bacteria isolated from hydrocarbon contaminated soils in the Diwaniya city/ Al-Qadisiya governorate | ||
| Jornal of Al-Muthanna for Agricultural Sciences | ||
| Article 1, Volume 2, Issue 1, November 2014, Pages 0-0 | ||
| Abstract | ||
| Abstract: As the usage of hydrocarbons increase soil contamination with diesel, engine and lubricating oils is becoming one of the major environmental problems this investigation was carried out to determine the bacterial flora of soils contaminated with used oils in the Diwaniya city / Al-Qadisiya governorate . Bacteria were screened for biosurfactants production by using oil spreading technique and hemolytic activity . Isolated bacteria were screened for the presence of one of the hydrocarbon degrading enzyme catechol 2,3 dioxygenase(C23O) and rhamnosyl transferase I (rhIB) enzyme which is involve in the production of biosurfactant by polymerase chain reaction amplification of genes using specific primers. Enrichment method was employed for the isolation of the bacteria . Soil samples from 17 different repairing car stations and electrical generators in the Diwaniya city were inoculated minimal salt medium (MSM) with crude oil as uniqe carbon source . The results showed that the bacterial species isolated were Pseudomonas spp. 14 isolates ( 66%) , Bacillus spp. 3 isolates (14%) , Micrococcus spp. 2 isolates (10%) and one isolate ( 5%) for each Staphylococcus spp. and Streptococcus spp. In case of the ability of bacterial isolates to produce biosurfactants , the results showed that using oil spreading technique ( among three different oils : crude oil , diesel and kerosene ) , kerosene was the best source for the production of biosurfactants in both Pseudomonas spp. and Bacillus spp. and Pseudomonas spp. showed higher activity than Bacillus spp. Also the results showed that oil spreading technique was better predicted biosurfactants production than the hemolytic activity . The difference in mean biosurfactant production by using two way ANOVA was found to be statistically significant at the p-values of p ˂ 0.05 (at 0.05 level of significance) between different methods and different bacteria . Molecular detection of C23O and rhIB genes, 12 isolates (58%) of degrading bacteria isolates from all twenty one bacterial isolates from contaminated soils expressed the C23O gene with highest percentage (43%) in Pseudomonas spp. This study showed that all Pseudomonas aeruginosa ability to produce rhIB gene and this DNA came from P. aeruginosa. | ||
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