Community composition of thePlanctomycetesassociated with different macroalgae

Abstract

Insights into the diversity of marine natural microbial biofilms, as for example those developing at the surface of marine macroalgae, can be obtained by using molecular techniques based on 16S rRNA genes. We applied denaturing gradient gel electrophoresis (DGGE) with 16S rRNA genes-specific primers for Planctomycetes to compare the communities of these organisms developing on six different macroalgae (Chondrus crispus, Fucus spiralis, Mastocarpus stellatus, Porphyra dioica, Sargassum muticum, and Ulva sp.) sampled in spring 2012 in two rocky beaches in the north of Portugal. Planctomycetes can be one of the dominant organisms found in the epibacterial community of macroalgae, and we wanted to determine the degree of specificity and the spatial variation of these group. Shannon diversity indexes obtained from the comparison of DGGE profiles were similar in all the macroalgae, and in both sites, F. spiralis was the algae presenting lower Planctomycetes diversity, while M. stellatus and P. dioica from Porto showed the highest diversity. The analysis of DGGE profiles, including anosim statistics, indicate the existence of a specific Planctomycetes community associated with the algal host, likely independent of geographical variation. Sequencing of DGGE bands indicated that Planctomycetes communities were highly diverse, and some Operational Taxonomic Units seemed to be specifically associated with each macroalgae.

Planctomycetes and macroalgae, a striking association

“…(Lage and Bondoso, 2011), and Laminaria hyperborea (Bengtsson and Ovreas, 2010). The presence of planctomycetes has also been confirmed in Fucus spiralis , Sargassum muticum by Bondoso et al (2013) and in Saccharina latissima and L. digitata (Bengtsson, unpublished results). These data suggest that planctomycetes are widespread among macroalgae which can be used for the discovery of novel planctomycetes species.…”

“…(Yoon et al, 2014), Ulva compressa (Hengst et al, 2010), Ulva intestinalis (Hengst et al, 2010; Lachnit et al, 2011; Lage and Bondoso, 2011), Ulva australis (Longford et al, 2007; Burke et al, 2011), Ulva prolifera (Liu et al, 2010), and Ulva sp. (Lage and Bondoso, 2011; Bondoso et al, 2013). This group was also reported to be present in the green macroalgae Chara aspera (Hempel et al, 2008) and Caulerpa taxifolia (Meusnier et al, 2001).…”

“…Isolates were retrieved from Chondrus crispus , Mastocarpus stellatus , Gracilaria bursa-pastoris , Gelidium pulchellum , Grateloupia turuturu , and Porphyra dioica (Lage and Bondoso, 2011). The presence of planctomycetes on Chondrus crispus , Mastocarpus stellatus , and Porphyra dioica was detected by molecular methods (Bondoso et al, 2013). A novel order of planctomycetes containing one species isolated from Porphyra sp.…”

“…Planctomycete communities on macroalgae can be highly diverse varying from only one to 24 OTUs at a 97% cut-off in the 16S rRNA gene per macroalgae (Table 1). With the use of specific primers for planctomycetes, Bengtsson and Ovreas (2010) defined 16 OTUs associated with the kelp Laminaria hyperborea , each representing a different species and Bondoso et al (2013), using PCR-DGGE, identified a total of 21 different OTUs associated with six macroalgae. In a pyrosequencing study, the red macroalga Porphyra umbilicalis was found to harbor 24 different OTUs belonging to planctomycetes (Miranda et al, 2013).…”

Bacterial degradation of dissolved organic matter released by Planktothrix agardhii (Cyanobacteria)

“…Also, Langenheder et al (2004) showed an increase on bacterial richness by DGGE profile in batch cultures during the stationary growth phase of the bacteria. Different bands representing the same OTU in DGGE gel (Figure 2) may be due to ambiguities in the sequences (Verleyen et al, 2010), since differences less than 0.6% may result in different bands (Bondoso et al, 2014) and we defined OTUs at 97% identity threshold.…”