Biodegradation of marine fuel MF-380 by microbial consortium isolated from seawater near the petrochemical Suape Port, Brazil

• A microbial consortium showed a high capacity to degrade marine fuel.
• Increased of C:N ratio is more suitable for the biodegradation process.
• Biodegradation in bioreactor higher than 80% for n-alkanes and 27% of marine fuel.

This work aimed to study the biodegradation of marine fuel MF-380 by selected microbial consortium and to determine the most favorable conditions for this process. Initially, strains isolated from seawater of the port of Suape – PE were subjected to a test to assess the occurrence of microbial interactions and then microbial consortia were mounted and the most promising consortium was selected by redox indicators. The strains of the selected consortium were acclimated to increasing levels of marine fuel MF-380 (1%, 2% and 3%, v v−1) and NaCl (1%, 2% and 3%, w v−1). Subsequently, it was applied a full factorial 23 experimental design to investigate the influence of variables (temperature, pH, C: N ratio) in the biodegradation process and finally an experiment in a bioreactor employing the best conditions found in the experimental design. Consortium named C5 was the most promising and reached as best result a total hydrocarbon biodegradation of 93.5% in the experimental design and reached levels of degradation optimized on trial in the bioreactor for the constituents of the marine fuel MF-380. Therefore, the consortium C5 is capable of degrading marine fuel MF-380 and can be used as a bioremediation agent of environments polluted by this fuel.