No abstract

In the present study, the effects of biosurfactant producing cells of different bacterial species namely Pseudochrobactrum lubricantisa, Lysobacter novalis, and crude biosurfactant extracted from Aspergillus niger were investigated as a cheap source to alleviate the availability of Pb 2+ for plants grown in El-Gabal El-Asfar area, Egypt. This is owing to these areas are basically depend on the reused wastewater for irrigation. Biosurfactant producing microorganisms were isolated from three different farms aged for 20, 40, and 60 years. The obtained results showed that, the biosurfactant producing bacteria decreased the availability of Pb 2+ in the outlet leachate during the leaching columns experiments. In contrast, Sr 2+ leachate showed the reverse trend that was observed with Pb 2+. Taguchi approach indicated that, the mechanisms of biosurfactant producing bacteria are very complicated and interfused with each other. The most factors affected the available form of Pb 2+ and Pb 2+ existed in organic form was Pb 2+ concentrations, however the exchangeable Pb 2+ , Pb 2+ bond to carbonate, Pb 2+ bond to sulfate, and plant content the most influential factors was biosurfactant producing bacteria. The most influential factors affected NPK uptake by watercress were found to take the following sequence biosurfactant producing bacteria > Sr 2+ doses > Pb 2+ doses.