Temporal patterns of bacterial community assembly within different fluctuation environments. Assembly Fluctuations

Here we studied how bacterial communities assemble over time under different degrees of environmental fluctuation. Using a lake mesocosm approach across a gradient of salinity, we established high, intermediate, and low fluctuation scenarios created by mesocosm size (24L, 70L, 200L) where we anticipated mesocosm stability to increase with size. We determined fluctuations based on measurements of environmental variables (pH, CDOM, TOC, TON, TP, temperature, conductivity) every four days, and every eight days we collected and calculated biological response variables (Chl-a, cell abundance, bacteria community diversity (weighted UniFrac distances)). Across the salinity gradient, environmental fluctuations of TOC, TON and TP were greatest in the smallest-volume mesocosms. Results of bacteria taxa were assessed by 16S rRNA amplicons (cDNA) using 300bp paired-end MiSeq Illumina sequencing.