Distinct Temporal Succession of Bacterial Communities in Early Marine Biofilms in a Portuguese Atlantic Port

Abstract

Marine biofilms are known to influence the corrosion of metal surfaces in the marine environment. Despite some recent research, the succession of bacterial communities colonizing artificial surfaces remains uncharacterized in some temporal settings. More specifically, it is not fully known if bacterial colonizers of artificial surfaces are similar or distinct in the different seasons of the year. In particular the study of early biofilms, in which the bacterial cells communities first adhere to artificial surfaces, are crucial for the development of the subsequent biofilm communities. In this work, we used amplicon-based NGS (next-generation sequencing) and universal 16S rRNA bacterial primers to characterize the early biofilm bacterial communities growing on 316 L stainless steel surfaces in a Northern Portugal port. Sampling spanned 30-day periods in two distinct seasons (spring and winter). Biofilm communities growing in steel surfaces covered with an anti-corrosion paint and planktonic communities from the same location were also characterized. Our results demonstrated that distinct temporal patterns were observed in the sampled seasons. Specifically, a significantly higher abundance of Gammaproteobacteria and Mollicutes was found on the first days of biofilm growth in spring (day 1 to day 4) and a higher abundance of Alphaproteobacteria during the same days of biofilm growth in winter. In the last sampled day (day 30), the spring biofilms significantly shifted toward a dominance of photoautotrophic groups (mostly diatoms) and were also colonized by some macrofouling communities, something not observed during the winter sampling. Our results revealed that bacterial composition in the biofilms was particularly affected by the sampled day of the specific season, more so than the overall effect of the season or overall sampling day of both seasons. Additionally, the application of a non-fouling-release anti-corrosion paint in the steel plates resulted in a significantly lower diversity compared with plates without paint, but this was only observed during spring. We suggest that temporal succession of marine biofilm communities should be taken in consideration for future antifouling/anti-biofilm applications.

Floating Wetland Islands Implementation and Biodiversity Assessment in a Port Marina

“…Cyanobacteria and Planctomycetes were also relevant phyla on biofouling and biofilm samples. Studies on biofouling growth on stainless steel plates in the same port marina as the present study, showed that the most abundant phyla were Cyanobacteria, Proteobacteria, Bacteroidetes, and Fusobacteria [31] as well as Proteobacteria, Bacteroidetes, Cyanobacteria, and Actinobacteria [53]. The average relative abundance of the main phyla for each type of samples (biofouling from the floating platform, biofilm from the planting media and water), is displayed in Figure 8, being the most abundant phyla Proteobacteria and Bacteroidetes (Appendix A Figure A1 shows the top 10 phyla found per sample analyzed).…”

“…Cyanobacteria and Planctomycetes were also relevant phyla on biofouling and biofilm samples. Studies on biofouling growth on stainless steel plates in the same port marina as the present study, showed that the most abundant phyla were Cyanobacteria, Proteobacteria, Bacteroidetes, and Fusobacteria [31] as well as Proteobacteria, Bacteroidetes, Cyanobacteria, and Actinobacteria [53]. The beta-diversity analyzed through the principal coordinates analysis (PCoA) ( Figure 9) showed a clear distinct communities' composition developed in the biofouling and biofilm compared with the water.…”

“…However, other factors must be considered such as the natural colonization process, and the possible seasonality referred. Antunes et al [53] also suggested that pioneer bacterial biofilm communities may face significant seasonal variations in the same location, when carrying out a study in the same port of the present study. They have stated that samples of biofilm retrieved from two different seasons had shown significant distinct taxonomic profiles and diversity patterns of the bacterial communities.…”

“…They have stated that samples of biofilm retrieved from two different seasons had shown significant distinct taxonomic profiles and diversity patterns of the bacterial communities. [53] when studying the biofilm growing on stainless steel surfaces in the same port, reported that the most abundant family found was Rhodobacteraceae, followed by Flavobacteriaceae, Halomonodaceae, and Alteromonodaceae families. The Shannon diversity index remained stable over time for each type of sample.…”

“…This top 20 also includes one taxon from the Flavobacteriales order and one taxon of Gammaproteobacteria class (unculture representative). Antunes et al [53] when studying the biofilm growing on stainless steel surfaces in the same port, reported that the most abundant family found was Rhodobacteraceae, followed by Flavobacteriaceae, Halomonodaceae, and Alteromonodaceae families. The average relative abundance of the main phyla for each type of samples (biofouling from the floating platform, biofilm from the planting media and water), is displayed in Figure 8, being the most abundant phyla Proteobacteria and Bacteroidetes (Appendix A Figure A1 shows the top 10 phyla found per sample analyzed).…”