Abstract
Biofilms are integral to many marine processes but their formation and function may be affected by anthropogenic inputs that alter environmental conditions, including fertilisers that increase nutrients. Density composition and connectivity of biofilms developed in situ (under ambient and elevated nutrients) were compared using 454-pyrosequencing of the 16S gene. Elevated nutrients shifted community composition from bacteria involved in higher processes (eg Pseudoalteromonas spp. invertebrate recruitment) towards more nutrient-tolerant bacterial species (eg Terendinibacter sp.). This may enable the persistence of biofilm communities by increasing resistance to nutrient inputs. A core biofilm microbiome was identified (predominantly Alteromonadales and Oceanospirillales) and revealed shifts in abundances of core microbes that could indicate enrichment by fertilisers. Fertiliser decreased density and connectivity within biofilms indicating that associations were disrupted perhaps via changes to energetic allocations within the core microbiome. Density composition and connectivity changes suggest nutrients can affect the stability and function of these important marine communities.
Acknowledgements
The authors especially thank B. Harris, S. Ushiama, N. Rivero, K. Edge and the members of the Applied Marine Ecology and Ecotoxicology laboratory for their assistance and support in the field and the laboratory. A. Campbell provided assistance with sample collection while M. Sun consistently gave invaluable advice with sample processing and analysis using QIIME.
Disclosure statement
No potential conflict of interest was reported by the authors.