COMPARATIVE STUDY OF ARCHAEAL COMMUNITY ASSOCIATED TO MARINE SPONGES FROM GUANABARA BAY AND CAGARRAS ISLAND IN RIO DE JANEIRO, BRAZIL

Aline da Silva Turque (UFRJ); Daniela Batista (UFRJ); Alexander Machado Cardoso (UEZO); Ricardo Pilz Vieira (UFRJ); Maysa Beatirz Mandetta Clementino (INCQS/FIOCRUZ); Cynthia Barbosa Silveira (UFRJ); Rodolpho Mattos Albano (UERJ); Guilherme Muricy (UFRJ); Orlando Bonifácio Martins (UFRJ)

We performed a survey of the archaeal communities associated to the sponges Hymeniacidon heliophila, Paraleucilla magna, Petromica citrina and seawater samples, from two different environments in Rio de Janeiro: Guanabara Bay, highly eutrophic estuarine system and non-impacted Cagarras island. We compared diversity and composition of the sponge-associated archaea based on 16S rRNA and ammonia monooxygenase subunit A (amoA) genes sequencing. Partial archaeal 16S rRNA sequences from seawater and sponges were retrieved by PCR, cloning, and sequencing. Sequences were subjected to DOTUR software. Rarefaction analyses, phylogenetic tree construction, and LIBSHUFF quantitative statistics were performed to verify coverage and similarity between libraries. Community structure of the inner bay archaea was different of the Cagarras Island both in seawater and sponges. As well, samples from inner bay were more diverse when compared to Cagarras Island. Among the two archaeal phyla, Crenarchaeota and Euryarchaeota, only the first was found in sponge libraries while both were found in seawater samples. Interestingly, the archaeal community found in Petromica citrina was exclusive of this sponge. The same pattern was observed for amoA gene. While most of the achaeal clones detected in this study seems to compose novel groups, some are afiliated to well describe microorganisms as Nitrosopumilus maritimus and Cenarchaeum symbiosum. The richness and diversity of archaea associated to these sponges, especially in the bay samples, suggest that marine sponges need the presence of the microorganism succeed in that environment. The concentration of ammonia in Guanabara bay is two orders of magnitude higher than Cagarras island, thus the presence of functional gene such as amoA, suggest that they may play important roles in the marine microbial ecology.