Nitrite accumulation performance and microbial community of Algal-Bacterial symbiotic system constructed by Chlorella...

Chlorella sp. and Navicula sp. were separately used to construct an algal-bacterial symbiotic system in two identical sequencing batch reactors (R₁ and R₂) to explore the influence of algal species differences on nitrite accumulation. The Navicula-bacterial symbiotic system showed a higher nitrite accumulation efficiency of 85% and a stronger resistance to ammonia load. It secreted twice as many extracellular polymeric substances than the Chlorella-bacterial symbiotic system. Nitrospira and SM1A02 were the dominant functional genera of nitrite-oxidizing bacteria in R₁. The dominant functional genus of ammonium-oxidizing bacteria and the dominant functional genus of denitrifying bacteria were Ellin6067 and unclassified_Saprospiraceae in R₂, respectively. In general, this research provided some reference for the construction of an algal-bacterial symbiotic system and achieving nitrite accumulation through an algal-bacterial symbiotic system.