Diversidade e potencial biotecnológico de actinomicetos recuperados do sedimento marinho coletado no arquipelágo São Pedro e São Paulo, Brasil

Abstract

Marine organisms are recognized for their ability to synthesize bioactive molecules with unique mechanisms of action peculiar structures. This study conducted a study about the biological diversity and biotechnological potential of microorganisms recovered from sediment samples St. Peter and St. Paul Archipelago (SPSPA) located almost a thousand miles from the Brazilian coast. The sediment samples were processed for isolation of cultivable microorganisms and to estimating microbial diversity based on the analysis of metagenomic DNA. The isolated cultures were grown on broth medium for the extraction with organic solvents and subsequent characterization of cytotoxic activity on human adenocarcinoma cells (HCT-116) and the chemical profile by liquid chromatography followed by mass spectrometry (LC-MS) and subsequent analysis on the basis of AntiMarin data. The study of diverse groups of bacteria and archaea through the DGGE techniques performed to the samples of the first (E1) and second semester (E2) showed that there is a marked similarity of 62.8% to the group of bacteria, whereas for Archaea, the similarity was 32.9%. In total 61UTOs from bacteria and Archaea were obtained for 32 OTUs. In relation to cultivable bacteria a total of 268 strains of bacteria was recovered from the 21 samples collected sediment. In the evaluation of biological activity, 41 extracts showed cytotoxicity, with IC50 ranging from 0.04 to 31.55μg/mL. From this result, three bacteria were chosen for bioguided fractionation of the active compounds. In the extract of BRA-132, identified as Salinispora sp., were identified bioactive compounds the group of staurosporinesbeyond saleniketals and rifamycin. Extract the BRA-199, identified as Streptomycessp., were isolated three diketopiperazines, however none of them showed cytotoxicactivity in addition to cytotoxic activity piericidin A and A glycol-piericidin A. Already BRA-177, identified as Actinomadura sp., were isolated the molecules cyclononilprodigiosin and nonilprodigiosin of the group prodigiosins, which have potent cytotoxic activity were isolated. These results demonstrate that, despite the low diversity observed by DGGE, the culturable bacteria SPSPA have high biotechnological potential.