| Autor: |
Glasl B; Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, 1030 Vienna, Austria., Haskell JB; CCMAR-Centre of Marine Sciences, CIMAR, University of Algarve, 8005-139 Faro, Portugal., Aires T; CCMAR-Centre of Marine Sciences, CIMAR, University of Algarve, 8005-139 Faro, Portugal., Serrão EA; CCMAR-Centre of Marine Sciences, CIMAR, University of Algarve, 8005-139 Faro, Portugal., Bourne DG; Australian Institute of Marine Science, Townsville 4810, Australia.; College of Science and Engineering, James Cook University, Townsville 4811, Australia., Webster NS; Australian Institute of Marine Science, Townsville 4810, Australia.; Australian Centre for Ecogenomics, University of Queensland, Brisbane 4072, Australia.; Australian Antarctic Division, Hobart 7050, Australia., Frade PR; CCMAR-Centre of Marine Sciences, CIMAR, University of Algarve, 8005-139 Faro, Portugal.; Zoological Department III, Natural History Museum Vienna, 1010 Vienna, Austria. |
| Abstrakt: |
Macroalgae play an intricate role in microbial-mediated coral reef degradation processes due to the release of dissolved nutrients. However, temporal variabilities of macroalgal surface biofilms and their implication on the wider reef system remain poorly characterized. Here, we study the microbial biofilm of the dominant reef macroalgae Sargassum over a period of one year at an inshore Great Barrier Reef site (Magnetic Island, Australia). Monthly sampling of the Sargassum biofilm links the temporal taxonomic and putative functional metabolic microbiome changes, examined using 16S rRNA gene amplicon and metagenomic sequencing, to the pronounced growth-reproduction-senescence cycle of the host. Overall, the macroalgal biofilm was dominated by the heterotrophic phyla Firmicutes (35% ± 5.9% SD) and Bacteroidetes (12% ± 0.6% SD); their relative abundance ratio shifted significantly along the annual growth-reproduction-senescence cycle of Sargassum . For example, Firmicutes were 1.7 to 3.9 times more abundant during host growth and reproduction cycles than Bacteroidetes . Both phyla varied in their carbohydrate degradation capabilities; hence, temporal fluctuations in the carbohydrate availability are potentially linked to the observed shift. Dominant heterotrophic macroalgal biofilm members, such as Firmicutes and Bacteroidetes , are implicated in exacerbating or ameliorating the release of dissolved nutrients into the ambient environment, though their contribution to microbial-mediated reef degradation processes remains to be determined. |
