Caracterização da população de Sargassum furcatum e seus epibiontes do banco da Ilha do Cabo Frio, Arraial do Cabo, RJ: sazonalidade e propriedades antibacterianas

Abstract

M acroalgae constitute a favorable habitat for a rich and diverse associated community . They are able to produce a wide range of biomolecules with applicat ion in biomedicine, cosmetics, food, and pharmaceutical industries and because of those properties, these organisms have been studied for biotechnological applications. The genus Sargassum is one of the richest marine macroalgae regarding associated commun ity. Furthermore , th e algae of this genus ha ve compounds with antioxidant, antitumoral, antimalarial, antiherbivore and antifouling properties. Considering the important relation between algal beds and epibiont community, as well as the ir importance to mar ine biotechnology research , the present study aim ed to increase the knowledge about Sargassum furcatum (Küetzing,1843) and its epibionts. Population parameters and their associated fauna were studied. Moreover , we tested the antibacterial properties of S. furcatum and its epibionts on marine bacteria present in biofouling growth . The present study was performed after five years of a collapse in the seasonal growth of the bed . Our results indicated that in the summer of 2015, the S. furcatum b ed showed a re markable growth and biomass increase , followed by the growth of epiphytes until the senescence of the host algae, despite the years of negligible growth. In terms of antibacterial activity, the present study showed that the crude extracts of S.furcatum sho wed inhibitory activity using different extraction solvents (aqueous, ethanol and dichloromethane). Epiphy tism influenced negatively the action of the extracts on the bacterial strains used. Our findings indicated that extracts of S. furcatum in dichlorome thane ( without epiphytes) showed superior inhibit ion on bacterial growth. Considering the important role of bacteria l growth and the formation of the biofilm to the initial phase of biofouling, the extract s obtained from the algae might have promising anti bacterial compounds that could be used for the development of a natural product - based antifouling paint.