Optimization of Culture Condition of An Indigenous Culture of Pseudomonas Citronellolis N1 Isolated from Coke Oven Wastewater

Abstract

Phenolic compounds are listed under priority pollutants by US EPA, and their concentration in effluent of several industries reached to 1000 mg l-1. However, investigation on biodegradation of phenolics from coke oven wastewater is found to be scanty. Therefore, an indigenous pseudomonas species with high toxicity tolerance and phenolic degradation abilities is isolated from coke oven wastewater. In order to enhance the rate of cresol biodegradation efficiency various culture conditions; such as pH, agitation speed (RPM) and inoculums size (OD600nm) is optimized by using response surface methodology (RSM) and central composite design (CCD) . Result revealed that agitation speed and inoculums size (OD600nm) played considerable influence on phenol degradation by the indigenous pseudomonas species. Further, among the three independent variables, interaction effect between pH and agitation speed (RPM) found to be significant on degradation of phenol. At the RSM optimized settings of pH 7.5, agitation speed 168 rpm, and inoculums size 1.3 (OD600nm), almost completely biodegradation of phenol is achieved at 700 mgl-1 of phenol within a short time period of 12h. Further, at this optimized culture condition more than 99 % of phenol degradation along with 95% of toxicity removal was attained at an initial phenol concentration of 1500 mgl-1 within a shorter time period of 94h. Thus, indigenous pseudomonas species can be possible used for the treatment of coke oven wastewater.