Screening potential of biosurfactant production from local bacterial isolates


A wide range of microorganisms can produce biosurfactants with attractive properties. Fifteen bacterial isolates have been collected (9 isolates from soil and 6 from water). The isolates characterized morphological 10 were gram-negative, and 5 were positive. All isolates were screened to perform their ability to produce biosurfactants (hemolysis and drop collapsing, emulsification, oil spreading, and foam production tests). The screening results for isolates' ability to produce biosurfactants showed that the highest value of the drop-collapsing test was recorded for the isolates F4, F5, F9, and F10. In contrast, isolate F13 recorded the highest value for the emulsification test. F11 had the highest value for the oil-spreading test, and the isolate F7 recorded the highest value for the foam test, while none of the isolates recorded hemolysis activity. The biosurfactant production of F9 and F6 show the highest yield 0.955 g/L and 0.68 g/L for the two isolates, respectively, is the highest compared with other isolates. The present study included five samples from each soil and water contaminated with petroleum hydrocarbons.