Burkholderia cepacia MSA47, A New Strain Isolated from the Rhizosphere of an Egyptian Salt Marsh Plant, Produced Potent Biosurfactant Applied for the Bioremediation of Oil Sludge-Polluted Soil

During the screening of bacteria isolated from the rhizosphere of an Egyptian salt marsh plant for the production of biosurfactants, it was found that a bacterial strain MSA47 was able to produce active biosurfactant (produced 176.6 cm2 ODA) in presence of waste frying oil (a cheap substrate). This strain was gram negative rods and identified as Burkholderia cepacia MSA47. This bacterial strain was able to utilize 5 different vegetable oils with the production of active biosurfactants (116.9 ?5.4 ? 176.6 ?0.0 cm2 ODA). Results of the effect of different soluble sugars showed that these substrates were not promising for the production of biosurfactant as compared to the hydrophobic substrates; this indicates that this B.cepecia strain prefers the hydrophobic substrates for the production of active biosurfactant. It was found that NH4NO3 and NaNo3 were best nitrogen sources, this was followed by the organic nitrogen source ??peptone??. The results also show that E24 values were higher against crude oil+Kerosene (74.4%) and crude oil (66.3%). This B.cepecia strain was able to produce biosurfactant stable at wide range of temperature (up to 121 ?C), wide range of pH values (2-12), and different NaCl concentrations (0-25% w/v). These properties give the biosurfactant produced by B.cepacia MSA47 a potential use in petroleum industries. Accordingly, the sterilized supernatant was used for enhancing the biodegradation of total hydrocarbons and PAHs during the bioremediation process to 69.0 ?6.9% and the biodegradation of the total of the 6 carcinogenic PAHs to 94.0%. In presence of NP alone, TPH degradation was 48.9%, and total carcinogenic PAH degradation was 86.6%. While in presence of a combination of BRNP, TPHs were degraded by 60.7%, and the total carcinogenic PAHs were 97.4%. These results indicate that the promising factor for enhancing the biodegradation of TPHs and PAHs compounds is the presence of BR. The results show that BR alone or in combination with NP fertilizers highly stimulated the native microorganisms in the oily sludge polluted soil to highly or completely degrade the carcinogenic PAH individuals found in the oily sludge. The use of BR will reduce the amount of fertilizers needed for the biodegradation process. On the other hand the use of BR alone enhanced the biodegradation of PAHs without fertilizers. This will reduce the cost of the bioremediation process.