Microbiota Bacteriana associada às esponjas de água doce da Amazônia

Abstract

Sponges are multicellular organisms classified in the phylum Porifera, been considered the most primitive metazoan. They present a cellular structure without true tissues. They live in tropical oceans, temperate and polar regions, and some species inhabit fresh water bodies. Sponges provide particular microenvironment conditions within their tissues. It allows them to the harboring of a diverse microbial community, which will be generating secondary metabolites. Those metabolites represent a source to search for new compounds of biotechnological interest. The ecological study of these microorganisms permits a better understanding of interaction dynamics and processes occurring in the environment. Different strategies could be applied to the analyze of genetic diversity of microorganisms in an environmental sample. Bacterias are key participants on natural ecosystems, mainly due their metabolic variability and adaptable physiology. Biocatalysis or biotransformation is the technique that uses biological catalysts to convert a substrate. It promotes chemical changes using enzymes (isolated or as parts of live microorganisms), The technology is competitive and doesn‟t harm the environment and is able to produce bioactive compounds with high enantiomeric purity. This work aims to characterize the microorganisms (bacteria) associated to freshwater sponges from two different Amazonian locations. The sponges were collected in the vicinities of the cities of Parintins and Manaus. Bacterias were grown and purified in selective medias. DNA extractions were made and sequencing of a 16S rDNA gene fragment performed for identification fingerprinting. The bioreduction reaction was performed with three bacterial strains and three substrates, p-nitroacetophenone, acetophenone and 3-hydroxy-2-methylene-3-(4'-nitrophenyl) methyl propanoic acid. The reaction progress was monitored by Gas Chromatography (GC) and Gas Chromatography Mass-Spectrometer (CG-MS). Hundred isolates were obtained from samples collected from Parintins and 117 isolates from Manaus. From these isolates, 31.5% were identified as belonging to Bacillus genus. Regarding the bioreduction reactions, the three bacterias showed the same retention time (13 minutes), and the reduction was considered as chemoselective, because bacteria reduced the nitro group present in amine. To our knowledge this is the first report of communities of bacteria associated to Amazonian fresh water sponges performing selective bioreduction. This work provide initial basis to further investigations of microbial communities in freshwater sponges in the Amazon region. Keywords: sponge – freshwater – bacteria - biocatalysis