Potencial biotecnológico de bactérias isoladas de macroalgas marinhas

Abstract

Bacteria associated with macroalgae are producers of several substances with biotechnological potential. However, to date, no study has evaluated the antibiotic activity of bacteria associated with macroalgae from Arraial do Cabo. The general objective was to study the antibacterial activity of bacteria associated with marine macroalgae. This work was divided into three chapters. The first chapter presents a general introduction, which corresponds to the theoretical framework. In the second chapter, the antibiotic activity of bacteria associated with marine macroalgae from Arraial do Cabo city was evaluated. For this, four different species of macroalgae were used (Sargassum vulgare, Colpomenia sinuosa, Pterocladiella capillacea and Ulva sp.). After the isolation of the strains, the antibacterial activity against ten indicator strains (fouling and pathogenic bacteria from the marine environment or of medical interest) was evaluated. The most active strains were identified from the 16S rRNA gene. In total, 61 strains were isolated from the four macroalgae collected, where 52 remained viable, of which 58 % showed antibiotic action against at least one of the indicator strains tested. The most active bacteria were identified as Gram-negative bacilli of the genus Vibrio and Gram-positive cocci of the genus Enterococcus. In the third chapter, a systematic review was carried out, with the objective of synthesizing the literature on bacteria associated with macroalgae and the production of substances with antibacterial activity, in addition to highlighting knowledge gaps on the subject and recommending paths for future research. Three databases were used, Scopus, Web of Science and Pubmed. In total, 73 articles were included and analyzed. The bacterial phyla that produced the most active antibacterial substances found associated with macroalgae were Proteobacteria, followed by Firmicutes and Actinobacteria. However, only 33 % of these studies identified the compounds produced by the bacteria. Those who identified found polyketides to be the most abundant class of compounds. Our results show that bacteria associated with macroalgae have an enormous biotechnological potential and are important sources for obtaining new bioactive substances.