ISOLATION AND IDENTIFICATION OF NOVEL BACTERIAL STRAINS WITH CRYSTAL VIOLET BIODEGRADATION POTENTIAL FROM TEXTILE EFFLUENT WASTEWATER IN EGYPT

Abstract

The textile industry is a significant player in the global economy; however, it is known for its contribution to environmental pollution by discharging untreated wastewater containing synthetic dyes. Crystal violet is a commonly used dye in the textile industry but has a harmful effect on humans and the environment. Therefore, developing a sustainable, environmentally friendly, and cheap method for crystal violet biodegradation like microbial biodegradation is crucial. To isolate bacteria degrading crystal violet, textile effluent wastewater was collected from different dying plants in Egypt. The degradation capacity of the bacteria isolated from textile effluent was measured using a spectrophotometer. The two bacterial isolates showing maximum crystal violet degradation FSL-1 and EBA-2, were identified using 16S rRNA as Klebsiella pneumoniae and Pseudomonas oleovorans, respectively. The effect of different parameters, including incubation time, initial dye concentration, pH, temperature, carbon source, agitation, and media composition, was studied on the ability of the two isolates to degrade crystal violet. The highest degradation of 92% was observed with K. pneumoniae isolate when inoculated in MSM-Y media containing 0.01 g/L crystal violet when incubated at 37 °C for 48 h under agitated conditions and pH 7; however, complete crystal violet degradation was observed when MSM-Y was substituted with brain heart infusion broth under the same conditions. Therefore, the newly identified bacterial strains in this study can be effectively utilized for the treatment of textile effluent containing crystal violet when certain parameters are optimized.