Stable and Enriched Cenarchaeum symbiosum and Uncultured Betaproteobacteria HF1 in the Microbiome of the Mediterranean Sponge Haliclona fulva (Demospongiae: Haplosclerida)

Abstract

Sponges harbor characteristic microbiomes derived from symbiotic relationships shaping their lifestyle and survival. Haliclona fulva is encrusting marine sponge species dwelling in coralligenous accretions or semidark caves of the Mediterranean Sea and the near Atlantic Ocean. In this work, we characterized the abundance and core microbial community composition found in specimens of H. fulva by means of electron microscopy and 16S amplicon Illumina sequencing. We provide evidence of its low microbial abundance (LMA) nature. We found that the H. fulva core microbiome is dominated by sequences belonging to the orders Nitrosomonadales and Cenarchaeales. Seventy percent of the reads assigned to these phylotypes grouped in a very small number of high-frequency operational taxonomic units, representing niche-specific species Cenarchaeum symbiosum and uncultured Betaproteobacteria HF1, a new eubacterial ribotype variant found in H. fulva. The microbial composition of H. fulva is quite distinct from those reported in sponge species of the same Haliclona genus. We also detected evidence of an excretion/capturing loop between these abundant microorganisms and planktonic microbes by analyzing shifts in seawater planktonic microbial content exposed to healthy sponge specimens maintained in aquaria. Our results suggest that horizontal transmission is very likely the main mechanism for symbionts' acquisition by H. fulva. So far, this is the first shallow water sponge species harboring such a specific and predominant assemblage composed of these eubacterial and archaeal ribotypes. Our data suggests that this symbiotic relationship is very stable over time, indicating that the identified core microbial symbionts may play key roles in the holobiont functioning.

Dry and Rainy Seasons Significantly Alter the Gut Microbiome Composition and Reveal a KeyEnterococcussp. (Lactobacillales: Enterococcaceae) Core Component inSpodoptera frugiperda(Lepidoptera: Noctuidae) Corn Strain From Northwestern Colombia

“…16S rRNA gene amplicons were obtained from the total DNA extractions and sequenced using the MiSeq Illumina platform. Alpha and beta diversity were estimated based on 97% similarity Operational Taxonomic Units (OTUS) using the QIIME 1.9.1 package ( Kuczynski et al 2011 ) using the pipeline as described by García-Bonilla et al (2019) . Variations in the relative abundance of OTUs in the respective seasonal conditions were tested for significance using the Kruskal–Wallis test.…”

Exploring Marine Planktonic Archaea: Then and Now

“…Additionally, using samples of C. symbiosum that we had sent him, Jaap Damsté and colleagues identified a new archaeal lipid, crenarchaeol, that could be linked specifically to the planktonic Nitrosopumilaceae lineage (Damsté et al, 2002). Since our early work on these archaeal sponge symbionts, C. symbiosum relatives have been reported in other sponges (Garcia-Bonilla et al, 2019; and references therein) as well. In addition, freeliving relatives of C. symbiosum were recently isolated in seawater ammonia-oxidizer enrichments originating from Hood Canal, Washington (Qin et al, 2020).…”

The Hologenome of Haliclona fulva (Porifera, Demospongiae) Reveals an Abundant and Diverse Viral Community

“…However, research works about marine sponge viromes and their relationship with the microbial status of the holobiont are still scarce. In the present study, we are reporting the characterization by shotgun metagenomics of the functional traits encoded in the virome of Haliclona fulva (Demospongiae: Haplosclerida), selected as a suitable holobiont model given its particular features of: (1) low microbial abundance, largely dominated by two bacterial and archaeal types (García-Bonilla et al, 2019), and (2) remarkable producer of a large metabolic repertoire of bioactive compounds such as fulvynes, alkaloids, peptides, and polyacetylenes (Nuzzo et al, 2012;Tribalat et al, 2016).…”