The last column in Table 1 shows the correlation (positive+ or negative-) between the position of a certain EP, WW or CW DGGE band towards the marker bands and its sequence identification. From this column we can deduce that most bands at positions of marker bands M1m, M2, M8 and M10 showed sequences that matched those of the marker bands and were thus identified as Mycoplasma, Arcobacter, Phyllobacteriaceae and Labrenzia species, respectively. All EP, WW or CW bands at the height of Bacteroidetes (M1b), chloroplast (M3 and M4), Flavobacteriaceae

(M5-7) and Xanthomonadaceae Nutlin 3a (M9) marker bands, however, showed a mismatch. Instead of being related to Bryopsis endophytic bacterial sequences, these latter band sequences were affiliated with Alphaproteobacterial (Caulobacterales,

Rhizobiales and Sneathiellales), Gammaproteobacterial (Alteromonadales and Oceanospirillales) and this website Acanthopleuribacterales sequences (see Table 1). To validate the true correspondence of excised EP, WW and CW bands with endophytic sequences, band sequences were clustered with previously obtained endophytic bacterial full length 16S rRNA gene sequences [3]. check details The UPGMA dendrogram (Figure 5) confirms that every one of the positively related bands (indicated with +) was highly similar (≥ 99.2%) to endogenous sequences (indicated in bold). This dendrogram illustrates that Arcobacter, Labrenzia, Mycoplasma and Phyllobacteriaceae endogenous sequences are also present in the epiphytic, washing water and/or cultivation water bacterial

communities of Bryopsis cultures, whereas Bacteroidetes, Flavobacteriaceae Pyruvate dehydrogenase lipoamide kinase isozyme 1 and Xanthomonadaceae sequences were strictly endogenous. In addition, Arcobacter and Mycoplasma sequences were only present in the EP, WW and/or CW bacterial communities of those Bryopsis MX samples in which they are also endogenously present. Labrenzia and Phyllobacteriaceae sequences, on the other hand, were also found in the EP, WW and/or CW bacterial communities of algal samples in which these species were not identified as being endophytic. Table 1 Taxonomic identification and phylogenetic affiliation of the excised and sequenced epiphytic (EP), washing water (WW) and cultivation water (CW) DGGE bands DGGE band number Closest matching strain in BLAST (accession number) Query coverage/Maximum identity Phylogenetic affiliation Correlation MX19 EP 1 Uncultured Mycoplasma sp. clone MX19.9 (JF521606) 100/100 Tenericutes; Mollicutes; Mycoplasmatales; Mycoplasmataceae M1m + M1b – MX19 EP 2 Uncultured bacterium clone Del10081H12 (JF262029) 100/100 Proteobacteria; Alphaproteobacteria; Caulobacterales; Hyphomonadaceae M4 – MX19 EP 3 Uncultured Phyllobacteriaceae bacterium clone MX19.