title: Sargassum decomposition microbiome 16S amplicons, day 2 replicate 1
design: Freshly collected samples of pelagic Sargassum were placed in a 0.84 m 3 tank (2  0.7  0.6 m). Pre-weighted samples were introduced in 10 home-made cylinders of flexible and dense plastic opened by both sizes to facilitate monitoring fresh weight changes along the experiment. A seed community of microbial decomposers was also placed at the head of the tank, next to the freshly collected samples but not in direct contact with them. This seed algal detritus was collected at the beach of the reef lagoon of Puerto Morelos from old material that had already initiated the decomposition process under aerobic conditions. We selected detritus with no evident signs of ongoing anaerobic processes. The samples located in each of the 10 cylinders were weighted at specific times and the cylinders were refilled with new, previously weighted, detritus from the material located in the tank, which was undergoing the same degradation process. Samples were removed at various time points from days 1 to 17 for microbiome DNA extraction, amplification and sequencing of the V4 region of the bacterial 16S rRNA gene.