eng Rovedar Research in Biotechnology and Environmental Science 2980-7743 2024-06-25 3 2 18 22 10.58803/rbes.v3i2.44 46 Alessia Lunetta 0 https://orcid.org/0000-0002-7066-9194 Maria Genovese 1 https://orcid.org/0000-0001-8100-9784 Salvatore Giacobbe 2 https://orcid.org/0000-0002-4619-4862 Sabrina Patania 3 https://orcid.org/0009-0005-2070-6312 Simone Cappello 1 https://orcid.org/0000-0002-5593-6004 1. Institute for Biological Resources and Marine Biotechnologies, Section of Messina, National Research Council (CNR-IRBIM), Spianata S. Rineri 86, 98122 Messina, Italy 1 Institute for Biological Resources and Marine Biotechnologies, Section of Messina, National Research Council (CNR-IRBIM), Spianata S. Rineri 86, 98122 Messina, Italy 2. Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, ChiBioFarAm, University of Messina, V.le Ferdinando Stagno D’Alcontres, 31, 98166 Messina, Italy 3 PhD School of “Applied Biology and Experimental Medicine”, Faculty of Sciences, University of Messina, Viale F. Stagno D’Alcontres 5, 98166 Messina, Italy Introduction: Microbes of sponges have diverse associations, including true symbiosis. Sponges, being evolutionarily ancient sessile filter feeders, host diverse and abundant microbial species that play crucial roles in host metabolism. Although the microbial symbionts of sponges are widely distributed within the organism (up to 40% of their volume), the ecological relationships and interactions between bacteria and their sponge host remain largely unexplored for many species. The present study was one of the first attempts to isolate symbiotic bacteria from the sponge Raspaciona aculeata. Materials and Methods: After isolation on marine agar medium, the isolates were characterized for different colony morphology. The 16S rDNA taxonomic analysis was carried out on bacteria isolates. Results: Following an incubation period of two weeks at 25°C, only 13 bacterial strains were isolated with a very low rate of genetic biodiversity. All strains belonged to the Gammaproteobacteria class (Pseudomonadaceae family), except one (isolate AL-18ra) belonging to the Bacilli class (Bacillaceae family). Conclusion: The obtained results are of great importance for advancing the understanding of symbiosis phenomena within the sponge species Raspaciona aculeata to study its bioapplication potential. https://rbes.rovedar.com/index.php/RBES/article/view/44 Pseudomonadacae Raspaciona aculeata Sponge Symbiont