Surface active agents (surfactants) are chemical compounds which are massively used as raw material in detergent production. Synthetic type surfactants are often used because they perform better and are more economical compared to natural detergents. Linear Alkyl Benzene Sulfonate (LAS) is one of the synthetic surfactants that is widely used. Although LAS is biodegradable, its introduction to the environment in big amounts harms water bodies. Research on biodegradation of LAS with 100 ppm, 400 ppm, 700 ppm, 1000 ppm and 1500 ppm concentrations was conducted by using consortium of bacteria comprising of Pseudomonas aeroginosa, Bacillus subtilis, Bacillus aglomerans, Bacillus cereus, Bacillus alvae. Experiments were carried out for twelve days, at 29oC with initial total inoculum of bacteria at 1,59 x 108 CFU/mL. Results showed that this type of bacterial consortium could tolerate 1500 ppm in LAS environment. However, significant growth rate did not occurr, 0.039 – 0.042 hour -1 and not too efficiently reduce Chemical Oxygen Demand (COD) for those systems. Surface tension in several variated concentration of LAS: 0 ppm >100 ppm >400 ppm >700 ppm, LAS 700 ppm = 1000 ppm = 1500 ppm
