Ten <i>Ostreobium</i> (Ulvophyceae) strains from Great Barrier Reef corals as a resource for algal endolith biology and genomics

Pasella, Marisa M.; Lee, Ming-Fen Eileen; Marcelino, Vanessa R.; Willis, Anusuya; Verbruggen, Heroen

doi:10.1080/00318884.2022.2064132

Cited by 6 publications

(18 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, we were unable to morphologically differentiate spatial microniches at the algal thallus level in these free-living Ostreobium growth forms (outside the carbonate habitat). Indeed, the orientation relative to a carbonate bioerosion front was absent in the thallus, composed of a tuft of branched interwoven filaments (Massé et al ., 2020, Pasella et al ., 2022). The siphonous cytology of microscopic Ostreobium thalli, with cytoplasmic streaming in septae-lacking tubes, presents a challenge for subsampling of individual filaments, for culture propagation or regionalized microbiota characterization.…”

Section: Discussionmentioning

confidence: 99%

“…Their thallus is composed of a network of interwoven, branching, giant coenocytic filaments, 10 to 20 µm in diameter and up to several hundred µm in length, with multiple nuclei and chloroplasts, and cytoplasmic streaming. These filaments erode galleries within the carbonate (bioeroding form), with epilithic 3-dimensional “tufts of filaments” when they emerge at its surface or when isolated in free-living growth form (Sauvage et al ., 2016; Massé et al ., 2020; Pasella et al ., 2022). In contrast, the coenocytic thalli of other siphonous Bryopsidale green algae such as Bryopsis and Codium (Bryopsidineae) or Caulerpa and Halimeda (Halimedineae) form macroscopic three-dimensional algal bodies, with morphologically differentiated frond-like axes (sometimes bearing lateral branches and cortical utricles) and basal anchoring rhizoids (Cocquyt et al ., 2010).…”

Section: Introductionmentioning

confidence: 99%

“…Identifying and visualizing bacterial associates of Ostreobium filaments, the endolithic coral algal ectosymbiont, remains an open challenge, which can be addressed by using coral-isolated Ostreobium strains. Indeed, such strains represent valuable biological model tools to experimentally investigate this algal biology in simplified in vitro systems (Massé et al ., 2020; Pasella et al ., 2022).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Bacterial microbiota ofOstreobium, the coral-isolated chlorophyte ectosymbiont, at contrasted salinities

Massé¹,

Detang²,

Duval³

et al. 2023

Preprint

View full text Add to dashboard Cite

Microscopic filaments of the siphonous green algae Ostreobium (Ulvophyceae, Bryopsidales) colonize and dissolve the calcium carbonate skeletons of coral colonies, in shallow-water reef environments of contrasted salinities. Their bacterial composition and plasticity in response to salinity remain unknown. Here, we analyzed the bacteria associated with coral-isolated Ostreobium strains from two distinct rbcL lineages, representative of IndoPacific environmental phylotypes, that had been pre-acclimatized (>9months) to three ecologically-relevant reef salinities: 32.9, 35.1 and 40.2 psu. Bacterial phylotypes were visualized at filament scale by CARD-FISH in algal tissue sections, localized to the surface, within filaments or in the algal mucilage. Ostreobium-associated communities, characterized by bacterial 16S rRNA metabarcoding of cultured thalli and corresponding supernatants, were structured by host genotype more than salinity and partly overlapped with those of environmental (Ostreobium-colonized) coral skeletons. Alphaproteobacteria dominated the thalli communities, enriched in Kiloniellaceae or Rhodospirillaceae depending on algal genotype. A small core microbiota composed of 7 ASVs (~1.5% of thalli ASVs, 19%-36% cumulated proportions), shared by multiple cultures of both Ostreobium genotypes and persistent across 3 salinities, included putative intracellular Amoebophilus and Rickettsiales bacteria. This novel knowledge on the taxonomic diversity of Ostreobium bacterial associates paves the way to functional interaction studies within the coral holobiont.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bacterial microbiota ofOstreobium, the coral-isolated chlorophyte ectosymbiont, at contrasted salinities

Massé¹,

Detang²,

Duval³

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Resulting dendrograms were exported in newick format. To generate the host phylogenetic tree, previously published tuf A sequences were used [32]. Sequences were aligned using MUSCLE [50] in Geneious Prime v2020.1.2 and a maximum likelihood host phylogeny built with the IQ-TREE web server with 1000 bootstraps and best-model selection enabled [51].…”

Section: Methodsmentioning

confidence: 99%

“…Cultures of five strains (VRM605, VRM642, VRM644, VRM646, VRM647) representing five clades (P3P14, C, P1K, P4, B3, respectively) of Ostreobium were used. Isolation of these strains from skeleton fragments of Great Barrier Reef corals and molecular identification were described previously [32]. To investigate likely physical associations, three sample processing protocols were employed which we will call 'whole', 'media'' and 'tight'.…”

Section: Study Design Sample Preparation and Dna Extractionmentioning

confidence: 99%

The bacterial microbiome of the coral skeleton algal symbiontOstreobiumshows preferential associations and signatures of phylosymbiosis

Pushpakumara

Verbruggen

Tandon

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Ostreobium, the major algal symbiont of the coral skeleton, remains understudied despite extensive research on the coral holobiont. The enclosed nature of the coral skeleton might reduce the dispersal and exposure of residing bacteria to the outside environment, allowing stronger associations with the algae. Here, we describe the bacterial communities associated with cultured strains of 5 Ostreobium clades using 16S rRNA sequencing. We shed light on their likely physical associations by comparative analysis of three datasets generated to capture (1) all algae associated bacteria (2) enriched tightly attached and potential intracellular bacteria and (3) bacteria in spent media. Our data showed that while some bacteria may be loosely attached, some tend to be tightly attached or potentially intracellular. Although colonised with diverse bacteria, Ostreobium preferentially associated with 34 bacterial taxa revealing a core microbiome. These bacteria include taxa known as nitrogen cyclers, polysaccharide degraders, sulphate reducers, antimicrobial compound producers, methylotrophs and vitamin B12 producers. By analysing co-occurrence networks of 16S rRNA datasets from Porites lutea and Paragoniastrea australensis skeleton samples, we show that the Ostreobium-bacterial associations present in the cultures are likely to also occur in their natural environment. Finally, our data show significant congruence between the Ostreobium phylogeny and the community composition of its tightly associated microbiome, largely due to the phylosymbiotic signal originating from the core bacterial taxa. This study offers insight into the Ostreobium microbiome and reveals preferential associations that warrant further testing from functional and evolutionary perspectives.

show abstract

The Bacterial Microbiome of the Coral Skeleton Algal Symbiont Ostreobium Shows Preferential Associations and Signatures of Phylosymbiosis

et al. 2023

Self Cite

View full text Add to dashboard Cite

Ostreobium, the major algal symbiont of the coral skeleton, remains understudied despite extensive research on the coral holobiont. The enclosed nature of the coral skeleton might reduce the dispersal and exposure of residing bacteria to the outside environment, allowing stronger associations with the algae. Here, we describe the bacterial communities associated with cultured strains of 5 Ostreobium clades using 16S rRNA sequencing. We shed light on their likely physical associations by comparative analysis of three datasets generated to capture (1) all algae associated bacteria, (2) enriched tightly attached and potential intracellular bacteria, and (3) bacteria in spent media. Our data showed that while some bacteria may be loosely attached, some tend to be tightly attached or potentially intracellular. Although colonised with diverse bacteria, Ostreobium preferentially associated with 34 bacterial taxa revealing a core microbiome. These bacteria include known nitrogen cyclers, polysaccharide degraders, sulphate reducers, antimicrobial compound producers, methylotrophs, and vitamin B12 producers. By analysing co-occurrence networks of 16S rRNA datasets from Porites lutea and Paragoniastrea australensis skeleton samples, we show that the Ostreobium-bacterial associations present in the cultures are likely to also occur in their natural environment. Finally, our data show significant congruence between the Ostreobium phylogeny and the community composition of its tightly associated microbiome, largely due to the phylosymbiotic signal originating from the core bacterial taxa. This study offers insight into the Ostreobium microbiome and reveals preferential associations that warrant further testing from functional and evolutionary perspectives.

show abstract

Ten Ostreobium (Ulvophyceae) strains from Great Barrier Reef corals as a resource for algal endolith biology and genomics

Abstract: Authors also thank the Heron Island Research Station staff for the support provided during the sampling campaign. Funding was provided by the Australian Research Council (DP200101613 to HV) and samples were collected under permit G13/36490.1..

Cited by 6 publications

References 38 publications

Bacterial microbiota ofOstreobium, the coral-isolated chlorophyte ectosymbiont, at contrasted salinities

Bacterial microbiota ofOstreobium, the coral-isolated chlorophyte ectosymbiont, at contrasted salinities

The bacterial microbiome of the coral skeleton algal symbiontOstreobiumshows preferential associations and signatures of phylosymbiosis

The Bacterial Microbiome of the Coral Skeleton Algal Symbiont Ostreobium Shows Preferential Associations and Signatures of Phylosymbiosis

Contact Info

Product

Resources

About