Effect of Phenol Concentration on Growth, Respiration and Biofilm Formation of Phenol-Degrading Bacteria in Isfahan Steal Plant Wastewater

Phenol and phenolic compounds are environmental pollutants that are found in industrial wastewater of oil refineries, coal tar, and chemical plants. Presences of these compounds in Isfahan steal plant have serious consequences for regional environment. Biodegradation is the best and economic method for refinement of phenol contaminated sites. In this research 15 phenol-degrading bacteria strains were isolated from different sites of Isfahan steal plant wastewater. Five dominant strains named as B3, C1, C4, C7 and D14 that had high capacity to eliminate phenol. Effects of different concentrations of phenol (100-900 mg/ml) on growth. Respiration and biofilm formation of 5 dominant strains were investigated. All strains grown well up to 500 mg/l of phenol concentration and eliminated it. Strains B3 had the most growth and biofilm formation on 300 mg/l. The majority strains had the best respiration growth and biofilm formation in 400-500 mg/l of phenol concentration. At 24 hours incubation time up to 500 mg/l phenol of phenol was degraded and at 48 hours incubation time 900 mg/l of phenol was degraded. By using these strains it could be possible to reduce phenol pollutant in phenol refinement pools of the Isfahan steal plant.