Bacterial Community Composition and Chromophoric Dissolved Organic Matter Differs with Culture Time of Skeletonema dohrnii

Skeletonema dohrnii is a common red tide microalgae occurring in the coastal waters and throughout world. The associated heterotrophic or autotrophic bacteria play vital roles regulating algal growth, production, physiology. In this study, we investigated detailed bacterial community structure with growth of S. dohrnii’s using high-throughput sequencing-based on 16S rDNA. Our results demonstrated that Bacteroidetes (48.04%) Proteobacteria (40.66%) all samples accounted for majority populations. There was significant linear regression relationship between abundance phyla culture time. Notable shifts composition were observed during growth: Flavobacteriales vast sequences at order level. Furthermore, relative Rhodobacterales gradually reduced whole process (0–12 days). However, beyond that, Marinobacter slowly increasing. It noteworthy five fluorophores (Peaks T1, T2, I, M, A) detected stage dohrnii. characteristic indexes (fluorescence index, humification biological index) chromophoric dissolved organic matter (CDOM) also varied addition, taxa had certain effects CDOM they inextricably linked to each other.