Effect of Bacterial Isolates From Soil Samples on Bisphenol A


Bisphenol A is known as one of endocrine disruptors compounds and has an acute toxicity to aquatic organisms in freshwater and marine species. Twenty five samples were collected from the soil around the Tigris River from different locations in Iraqi cities, and 45 bacterial isolates were obtained. Three of these isolates were further tested for their degrading capacity of Bisphenol A (BPA) in Basal Mineral Medium, included: Pseudomonas orizohibtanis, Escherishia coli and Proteus penneri. The optimal temperature for the removal of BPA was tested at 20˚C, 37˚ and 45˚C for 1, 5, and 15 days, and the degradation increased up to a temperature of 37°C. Growth test was performed on isolated bacteria with BisPhenol A as the sole carbon source, and with increasing incubation time, the culture grew almost linearly to 24 hours. BPA decreased after 1days after incubating with tested bacterial isolates, and almost broken after 5 days, while it disappeared after 15 days at 37C, and Pseudomonas orizohibtanis exhibited the best degradation of BPA. The absorbance peaks in the UV region appeared at 222 and 276 nm and attributed to the benzene ring and triazine ring respectively. The end products of BPA degradation were analyzed by GCMS after 15 days of incubation. The chromatogram for Pseudomanas orizohibtanis showed three peaks at retention times of 70, 210 and 280 min, and referred to hexasiloxane, heptasiloxane, and Octasiloxane respectively. The bacterial isolates from the soil around Tigris River had the ability to degrade Bisphenol-A, and it could graw in different environmental conditions, also this degradation process produced many of active materials which it is useful in many applications.