Microbial diversity in Mediterranean sponges as revealed by metataxonomic analysis

Nadia Ruocco,Valerio Zupo,Roberta Esposito,Marco Bertolino,Giacomo Zagami,Federico Andreani,Stefania Crispi,Maria Costantini,Michele Sonnessa,Sergio De Matteo

doi:10.1038/s41598-021-00713-9

Abstract

Although the Mediterranean Sea covers approximately a 0.7% of the world’s ocean area, it represents a major reservoir of marine and coastal biodiversity. Among marine organisms, sponges (Porifera) are a key component of the deep-sea benthos, widely recognized as the dominant taxon in terms of species richness, spatial coverage, and biomass. Sponges are evolutionarily ancient, sessile filter-feeders that harbor a largely diverse microbial community within their internal mesohyl matrix. In the present work, we firstly aimed at exploring the biodiversity of marine sponges from four different areas of the Mediterranean: Faro Lake in Sicily and “Porto Paone”, “Secca delle fumose”, “Punta San Pancrazio” in the Gulf of Naples. Eight sponge species were collected from these sites and identified by morphological analysis and amplification of several conserved molecular markers (18S and 28S RNA ribosomal genes, mitochondrial cytochrome oxidase subunit 1 and internal transcribed spacer). In order to analyze the bacterial diversity of symbiotic communities among these different sampling sites, we also performed a metataxonomic analysis through an Illumina MiSeq platform, identifying more than 1500 bacterial taxa. Amplicon Sequence Variants (ASVs) analysis revealed a great variability of the host-specific microbial communities. Our data highlight the occurrence of dominant and locally enriched microbes in the Mediterranean, together with the biotechnological potential of these sponges and their associated bacteria as sources of bioactive natural compounds.

Highlights

Sampling site Faro Lake Faro Lake Faro Lake Punta San Pancrazio Porto Paone Porto Paone Punta San Pancrazio Secca delle Fumose, Parco Sommerso di Baia
Several studies have highlighted the biotechnological potential of bacterial communities in marine sponges through the identification of PKSs and NRPSs genes, encoding for secondary metabolites[9,10,11,12,13]
Basic Local Alignment Search Tool (BLAST) similarity search corresponded with the morphological identification achieved with two (S.spi and E.dis) of the three sponge samples collected in the Faro Lake (Sicily; see Tables S1-S2)

Summary

Introduction

Sampling site Faro Lake Faro Lake Faro Lake Punta San Pancrazio Porto Paone Porto Paone Punta San Pancrazio Secca delle Fumose, Parco Sommerso di Baia. Sand, mud, coralligenous concretions, Posidonia meadows and caves vancomycin), polyketides (erythromycin and tetracycline) and hybrid peptide polyketides (cyclosporin A and rapamycin) Some of these molecules are synthesized by non-ribosomal peptide synthases (NRPSs) and polyketide synthases (PKSs), which are encoded by genes clustered in the g enome[7,8]. Anthropogenic activities together with climate changes are strongly impacting the biodiversity of the M editerranean[18,19] and, as a consequence, this facilitates the spreading of alien s pecies[20] Examples of these environmental events are Paraleucilla magna, a sponge firstly described in 2004 off the Brazilian waters and widespread in many areas of the M editerranean[21]. The ASVs analysis was discussed to evaluate the biotechnological potential of sponges under investigation, in view of literature data

Methods

Results

Conclusion