Metagenomic insights into the impact of photoperiod on nitrogen removal efficiency and mechanisms in photogranules: A community functional perspective

This study set up reactors with four different light-to-dark ratios using marine aquaculture wastewater to cultivate photogranules: L1 (2:4), L2 (3:3), L3 (4:2), and L4 (5.5:0.5). We investigated the morphological characteristics, nitrogen removal efficiency, nitrogen removal kinetics, microbial community structure, and functions of photogranules. We aimed to elucidate the influence of photoperiod on photogranules, and to reveal the mechanisms of nitrogen removal by photogranules based on metagenomics.