Salinity affects compositional traits of epibacterial communities on the brown macroalgaFucus vesiculosus

Abstract

Epibiotic biofilms have the potential to control major aspects of the biology and ecology of their hosts. Their composition and function may thus be essential for the health of the host. We tested the influence of salinity on the composition of epibacterial communities associated with the brown macroalga Fucus vesiculosus. Algal individuals were incubated at three salinities (5, 19, and 25) for 14 days and nonliving reference substrata (stones) were included in the experiment. Subsequently, the composition of their surface-associated bacterial communities was analyzed by 454 pyrosequencing of 16S rRNA gene sequences. Redundancy analysis revealed that the composition of epiphytic and epilithic communities significantly differed and were both affected by salinity. We found that 5% of 2494 epiphytic operational taxonomic units at 97% sequence similarity were responsible for the observed shifts. Epibacterial α-diversity was significantly lower at salinity 5 but did not differ between substrata. Our results indicate that salinity is an important factor in structuring alga-associated epibacterial communities with respect to composition and/or diversity. Whether direct or indirect mechanisms (via altered biotic interactions) may have been responsible for the observed shifts is discussed.

Composition of Bacterial Communities Associated with Aurelia aurita Changes with Compartment, Life Stage, and Population

“…The extent of change in OTU composition explained by the above-mentioned experimental factors was explored by redundancy analysis (RDA) with Hellinger-transformed OTU abundances (41,52,53). In general, the RDA model was formulated as "OTU abundances ϳ F," with factor F being either "life stage," "provenance," or "compartment."…”

Evaluation of a new primer combination to minimize plastid contamination in 16S rDNA metabarcoding analyses of alga‐associated bacterial communities

“…Bacteria can be abundant on macroalgal surfaces, ranging from 10 6 to 10 7 cells cm −2 , and encompass a large phylogenetic diversity (van der Loos et al ., ). These communities are distinct from bacterial assemblages found in the surrounding seawater or on inert surfaces (Burke et al ., ; Stratil et al ., ; Lemay et al ., ). The composition of algae‐associated bacterial communities has been shown to be host‐specific and to vary depending on algal tissue, seasons, sampling sites and physiological status of the algae (Staufenberger et al ., ; Lachnit et al ., ; Miranda et al ., ; Stratil et al ., ; Zozaya‐Valdes et al ., ; Aires et al ., ; Paix et al ., ).…”

Temporal covariation of epibacterial community and surface metabolome in the Mediterranean seaweed holobiont Taonia atomaria

“…The surface‐associated bacterial communities of the Phaeophyceae Fucus vesiculosus from the Western Baltic Sea shores have been found to vary seasonally and be algal species specific (Lachnit et al ., ). In addition, temperature and salinity shifts appear to modify the α ‐diversity as well as the composition of these bacterial communities (Stratil et al ., ; ). Dimethylsulphoniopropionate (DMSP), proline and fucoxanthin, identified at the surface of F. vesiculosus, inhibit bacterial attachment (Saha et al ., ; Saha et al ., ) and mainly impact the abundance of surface communities (Lachnit et al ., ).…”