“…A microbial surfactant (biosurfactant) especially the rhamnolipid biosurfactant was investigated for its potential to enhance bioavailability, and hence the biodegradation of octadecane (Zhang and Miller, 1992); crude oil (Nelly et al, 2004;Zhang et al, 2005Zhang et al, , 2009; different carbon sources (n-hexadecane, paraffin oil, glycerol, and molasses) (Rashedi et al, 2006); xylene, benzene, n-hexane, Bombay high crude oil, kerosene, gasoline, and diesel fuel (Thahira et al, 2003); Arabian light crude, Al-Shaheen crude, diesel, and oil slops (Eugene et al, 2006). Also, many researchers studied the biodegradation of oily wastes as well as the production of biosurfactants (Cameotra and Singh, 2009;Gokcen et al, 2008;Reda and Ashraf, 2009;Suppasil and Kulnaree, 2007;Zhang et al, 2009;Zheng et al, 2007). The present study was focused on the effect of the initial oil concentration on the efficiency of oil biodegradation and rhamnolipid production using Pseudomonas aeruginosa ATCC 9027.…”