Efectos tóxicos del alquilbencensulfonato lineal, antraceno y su mezcla sobre el crecimiento de un consorcio microbiano aislado de sedimento contaminado

The aim of this study was to determine the effect of linear alkylbenzene sulfonate (LAS), anthracene and a LAS-anthracene mixture on the growth of a microbial consortium isolated from polluted sediment. The microbial consortium was grown in a sterile glass bottle with mineral medium containing 1 g/L of glucose. Microbial growth inhibition produced by LAS, anthracene and combinations of LAS and anthracene was determined by viable count in nutritive agar; inhibitory concentration 50 (IC 50 ) was calculated. The concentrations evaluated were 0.16, 0.8, 1.6, 16 and 160 mg/L of LAS or anthracene. The LAS-anthracene mixtures were prepared by fixing either LAS or anthracene at 0.16 mg/L while increasing the other compound at the above concentrations. Microbial growth was sensitive to LAS at an IC 50 of 8.22 and to anthracene at an IC 50 of 5.2 mg/L. In the LAS-anthracene combination, if LAS concentration was fixed and anthracene concentration varied, IC 50 (5.92 mg/L) was similar to IC 50 for anthracene alone. In contrast, the inhibition effect was diminished when anthracene remained constant and LAS concentration was increased (IC 50 : 70.11 mg/L). The sediment microbial populations were capable of degrading the LAS-anthracene mixture if the concentration of both compounds were at 0.16 mg/L.