الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The main objective of this study was to isolate and define some of the isolates that could represent hydrocarbons in oil and to determine the optimal environmental and nutritional conditions to enhance and improve the efficiency of microbial oil decomposition and to test the ability of breeds to produce surfactants and their adhesion to oily materials. Forty five of bacterial isolates were isolated, from which only three were capable to grow on HB medium containing crude oil as a sole carbon source, Referring to morphological and molecular characterization, Oil-degrading isolates were identified as Pseudomonas reinekei MT1, Kosakonia pseudosacchari JM-387 Enterobacter tabaci YIM Hb-3,The optimum temperature for all 3 strains was 30ºC, Oil degradation after 15 days by Pseudomonas reinekei MT1, Kosakonia pseudosacchari JM-387 Enterobacter tabaci YIM Hb-3, The optimum pH value for the three bacterial strains was 7. Oil degradation on pH 7 after 15 days by Pseudomonas reinekei MT1, Kosakonia pseudosacchari JM-387 Enterobacter tabaci YIM Hb-3, Additive nitrogen sources affects in different ways on oil degradation and growth of bacterial strains after 15 days of incubation on 30ºC and pH 7. Sodium nitrate gave highest oil degradation with Pseudomonas reinekei MT1, Also sodium nitrate recorded highest oil degradation with Kosakonia pseudosacchari JM-387, Ammonium sulphate gave highest oil degradation by Enterobacter tabaci YIM Hb-3, Addition of oil derivatives in mixtures with crude oil stimulated oil degradation in some cases and decreased in another cases. Addition of benzene to crude oil increased oil degradation and bacterial growth by Pseudomonas reinekei MT1, Petroleum ether increased oil degradation and bacterial growth by Kosakonia pseudosacchari JM-387, While addition of acetone increased oil degradation and bacterial growth by Enterobacter tabaci YIM Hb-3, Addition of surfactants increased oil degradation by all three bacterial strains. Addition of triton X10 to crude oil and benzene increased oil degradation and bacterial growth by Pseudomonas reinekei MT1 after 15 days, Also addition of triton X10 to crude oil and petroleum ether increased oil degradation and bacterial growth by Kosakonia pseudosacchari JM-387 after 15 days, other side, tween 80 + crude oil gave highest oil degradation and bacterial growth with Enterobacter tabaci YIM Hb-3, All strains could grow in salinity of 1 and 2%, where oil degradation and bacterial growth decreased with the increases in salinity. Also the three strains could not stand with salinity over 2%; there was no growth and no oil degradation. Oil degrading bacterial isolates were tested to determine their ability for biosurfactants production during degrading oil. from the overall study, three bacterial strains were able to degrade crude oil efficiently and recommend applying it for bio cleaning polluted environment and take their optimum conditions in the consideration.