Screening of Bacteria in the Biodegradation of Linear Alkyl Benzene Sulfonate (LBAS) From Car Wash Waste Water in Tehran (Iran)

Linear alkyl benzene sulfonate (LABS) is a substance used as a surfactant in anionic detergents. Today, it is the most widely used surfactant in detergent products after soap. The aim of this study was to screen effective isolates for the degradation of LABS from car wash effluents in Tehran (Iran). In this study, 10 effluent samples were randomly collected from car washes in Tehran (Iran). Isolation of mesophilic aerobic bacteria was performed by direct and pre-enrichment culture techniques. Biodegradation of sodium dodecyl sulfonate by isolates and turbidity was investigated by methylene blue active substance (MBAS) method, and the superior strain was identified by molecular method (Polymerase Chain Reaction, PCR), which approximately 86% of the material was degrade by the bacterial isolate, and the isolate was identified as Bacillus licheniformis.The results of MBAS method showed that the rate of LBAS degradation by bacteria was 86%, which indicates the high power of this bacterium to degrade LABS from sewage systems (car wash effluents). It was also shown that the concentration of LABS during 8 days of biodegradation period by this bacterium decreased from 80%, which indicates a significant decrease in LABS by Bacillus licheniformis. According to our results, Bacillus licheniformis can be used to dagrade LABS and its degradation in wastewater treatment systems of car wash effluents whose effluents are based on alkyl benzene sulfonates.