Evaluación de la capacidad de degradación de fenol por consorcios bacteria-microalga aislados de la bahía de Cartagena, Colombia

The development of new technologies for environmental reparation has allowed the application of inexpensive alternatives such as bioremediation, which has a high potential to treat ecosystems polluted with hydrocarbons. Microalgae-bacteria consortia have been identified as an efficient alternative for the detoxification of organic and inorganic contaminants and the removal of toxic compounds. This work investigates the phenol degradation potential of several alga-microbial consortia, which involved the algae Chlamydomonas reinhardtii and an osmotolerant phenol-resistant bacterial strain isolated from the bay of Cartagena, Colombia. A total of three bacterial strains were tested (i.e. Stenotrophomonas maltophilia, Microbacterium paraoxydans and Paenibacillus lactis) individually and in consortium with C. reinhardtii. Our data indicate a significant increase in the growth rate and a reduction in the lag phase of microorganisms in the consortium as compared to microorganisms growing in isolation. Interestingly, the inoculum ratio 2:1 (bacteria-microalgae) was shown to be the most robust taking into account that both microorganisms improved their growth. Afterward, the phenol degradation capacity of pure cultures and consortia in the presence of different phenol concentrations was evaluated. Our results reveal that such consortia perform better at low phenol concentrations; more specifically, the consortium Microbacterium paraoxydans-Chlamydomonas reinhardtii was the most effective: it reached a 49.89% phenol removal.