Potential biodegradation of crude petroleum oil by newly isolated halotolerant microbial strains from polluted Red Sea area

Two microbial isolates from oil polluted Red Sea water in Egypt, designated as RS-Y1 and RS-F3, were found capable of degrading Belayim mix (BX) crude oil. Strains RS-Y1 and RS-F3 were assigned to the genera Lipomyces tetrasporus and Paecilomyces variotii based on their morphological and physiological characteristics. Both isolates were compared for the biodegradation of crude petroleum-oil hydrocarbons in basal salt medium supplemented with 5% (w/v) of BX-crude oil. Gas chromatography profile showed that the biodegradation of total petroleum hydrocarbons (TPHs) inoculated with L. tetrasporus (68.3%) and P. variotii (58.15%) along with their consortium (66%) significantly reduced TPHs levels as compared to the control after 30days. L. tetrasporus (44.5%) was more effective than P. variotii strain (32.89%) in reducing the unresolved complex mixtures (UCM) content from the medium. Both isolates exhibited a strong growth over a wide range of salinity (5–45g/L NaCl). •Novel microbial strains were isolated from crude oil-contaminated Red Sea water.•The strains were identified as Lipomyces tetrasporus and Paecilomyces variotii.•Both isolates degraded the total petroleum hydrocarbons by more than 55%.•L. tetrasporus tolerate 45g/L salt and maintain its biodegradation efficiency.•The consortium approach improved the biodegradation ability.