The bacterial evaluation of maize root (Zea mays L.) in oil-polluted soil

Total petroleum hydrocarbons (TPHs) is one of the most important environmental challenges. Phytoremediation of oil-polluted soil depends on microorganisms of the rhizosphere. This study attempts to evaluate the microbial impact of Zea mays rhizosphere during a 60 day period using three different treatments: control soil، oil-polluted soil and oil-polluted soil including fertilizer (NH4No3، K2HPO4). Then، the rhizosphere bacteria were identified. The results showed that CFU per gram of control soil was higher than other treated soils، an indication of oil stress on microbial population. In addition، more bacterial diversity was observed in soils and different bacteria were isolated from the soils. Finally، the most resistant bacteria to the oil pollution were assayed. The assay of isolates indicated that all of those separated from the oil-polluted soil have the ability to produce biosurfactant in different quantities. Further investigation must be carried out to optimize the degradation of oil by these isolates.