Bacterial biosurfactant from Citrobacter freundii MG812314.1 as a bioremoval tool of heavy metals from wastewater

Abstract

The problem of heavy metal contamination is a global issue, and the challenge is to develop methods to remove heavy metals from soil and water. Recently, biosurfactants are one of the compounds that provide an attractive eco-friendly alternative to the physicochemical process in alleviating the heavy metals. Sixty bacterial isolates were isolated from Al-Rahawy drain sediments and screened for biosurfactant production. Only 10 isolates were recoded as biosurfactant producers by the oil spreading and emulsifying assays in addition to the ability of biosurfactant on heavy metal removal in wastewater. The most potent isolate was identified using morphological, cultural, biochemical characteristics, antibiotics susceptibility, and 16 s rRNA technique as Citrobacter freundii MG812314.1. The produced biosurfactant was found to be more effective in removing heavy metals from wastewater, viz 80, 67, 66, 55, 45, 44, and 41% of aluminum, lead, zinc, cadmium, iron, copper, and manganese, respectively, under two inoculum potentials and two contact time. The interaction of heavy metals with biosurfactant was monitored using scanning electron microscope (SEM), energy dispersive X-ray spectra (EDX), and Fourier-transform infrared spectroscopy (FTIR) analyses.