ABSTRACT Spent automotive lubricating oil contains complex hydrocarbons and heavy metals, posing environmental risks when discarded improperly. Bioremediation with native microorganisms offers a sustainable solution. This study evaluated the biodegradation potential of a bacterial directly isolated from used oil and a bacterial consortium obtained from seawater collected at Ilha do Cardoso (São Paulo, Brazil). The isolate was identified as Bacillus sp., whereas the consortium included three strains of Enterobacter and 13 strains of Acinetobacter . A salt medium with used oil as the sole carbon source was employed to assess growth, biosurfactant production and oil degradation. Optimal growth occurred at 0.2% (v/v) oil after 5 days. Growth kinetics showed higher rates for the consortium (0.529 ± 0.050 day −1 ) compared to Bacillus sp. (0.147 ± 0.010 day −1 ). Oil removal reached 31.8% for the consortium and 22.2% for Bacillus sp., both above abiotic control. Results highlight microbial consortia as effective agents for oil bioremediation.
Costa et al. (Thu,) studied this question.