Effect of Phytogenic Biosurfactant on the Microbial Community and on the Bioremediation of Highly Oil-Polluted Desert Soil

Abstract

The effect of a phytogenic surfactant on the microbial community and on the biodegradation of crude oil in a highy polluted desert soil (8%) were investigated. The addition of this biosurfactant increased total heterotrophie bacteria (THB) to reach the range of 4.3 – 20.3 CFUx108g dried soil, with increased factor of 7.18 – 10.38. Oil-degraders were in the range of 2.48-30.2 CFUx107 in presence of the biosurfactant, this in a range of 27.2-143.8 increased factor Higher percentages of 5.7-17.6% of the oil degraders were recorded in presence of biosurfactant. In presence of biosurfactant the biodegradation rate of the oil increased to reach 23.8-30.0% after 90 days, this is in contrast to 3.8-10% in the absence of this biosurfactant. The maximum biodegradation of the saturates and the aromatic fraction were 92.8% and 41.8% respectively in presence of the biosurfactant. Based on these results it is advisable to use this cost-effective phytogenic surfactant for cleaning the highly oil-polluted sites especially in the absence of NP fertilizer