Denitrification performance and microbial diversity in a packed-bed bioreactor using biodegradable polymer as carbon source and biofilm support

► Starch/PCL (SPCL) blend was prepared and used for biological denitrification. ► The microbial community of attached biofilm was analyzsed by metagenomic method. ► The vast majority of species biofilm (99.71%) belonged to six major phyla. ► Proteobacteria were the most abundant phylum (85.50%). ► Diaphorobacter and Acidovorax was 52.75% of identified denitrifying bacteria.