BIODEGRADABILITY OF MICROCYSTINS BY BACTERIA ASSOCIATE IN CARBON BIOLOGICAL FILTRES

Alessandro Minillo (UNESP); Sarah Freitas (UNESP); Heloiza Ferreira Alves Prado (UNESP); William Deodato Isique (UNESP); Mauricio Rocha Dimitrov (UNESP); Douglas Antônio Alvaredo Paixão (UNESP); Mariana Angel Pereira (UNESP); Eliana Gertrudez de Macedo Lemos (UNESP)

Microcystins (MCs) are a group of cyclic heptapetide hepatotoxins produced by cyanobacteria. MCs are fatal to fish, domestical animals and even humans, with reported effect carcinogenic through tumor promotion. The persistence of MCs in aquatic environments and their difficult removal in the conventional water treatment is a challenge to companies of sanitation. However, the MCs are susceptible to degradation by bacteria present in water, sediment and sewage effluents. The objective of this study was to evaluate the biodegradation of MCs by bacteria present in carbon filters with biological activity (BAC) in the batch system. A study of water containing microcystins (20 μg L^-1) was used, with and without addiction supplemented of specific medium for cultivation, plus an inoculum of the effluent filters BAC. The bacteria associate in biofilm were classified phylogenetically on the basis of 16S rRNA sequencing analysis. The tests were performed in duplicate, in the dark, with stirring, for 84 days, with analyses of MCs weekly. The results showed that of MCs were biodegraded (99%) by bacteria present in the medium. This study provides the ability to complete biodegradation of MCs by bacteria (Acinetobacter, Pseudomonas, Cupriavidus and Stenotrophomonas) present in BAC filters, and the possible use of these microorganisms as alternative control and removal of MCs in the treatment of drinking water.