Unlocking the potential of Komagataeibacter europaeus FMES: A novel source of bacterial cellulose from Monascus vinegar biofilm

• A BC-producing strain K. europaeus FMES was isolated from Monascus vinegar biofilm. • The microbial profile of Monascus vinegar biofilm was analyzed for the first time. • The complete genome of K. europaeus FMES was determined by whole genome sequencing. • Carbon source metabolism and BC synthesis pathways of strain FMES were elucidated. • The highest BC yield was obtained using 5% glycerol as a single carbon source. Various bacterial species synthesize bacterial cellulose (BC), each exhibiting unique metabolic pathways and environmental adaptations. Herein, the microbial profile of Monascus vinegar biofilm was analyzed for the first time using metagenome sequencing, and a BC-producing bacteria, Komagataeibacter europaeus FMES, was isolated from Monascus vinegar biofilm and identified as a novel strain. The complete genome of strain FMES was analyzed using whole genome sequencing, revealing carbon metabolism and BC biosynthesis pathways in detail. The biosynthesis of BC is regulated by the bacterial cellulose synthase ( bcs ) operon, and three bcs operons were identified in the genome. Additionally, the BC production of strain FMES was evaluated under static conditions using different carbon sources. The highest BC yield of 5.89 ± 0.38 g/L was achieved using 5% glycerol as the only carbon source. The addition of 3% ethanol enhanced the biosynthesis of BC by K. europaeus FMES. This work brings valuable insights into the isolation of BC-producing strains from fermented foods and the metabolic pathways of BC synthesis, which provides useful information for further biological research on Komagataeibacter spp., and the potential use of BC in medical wound care and sustainable packaging.