Biofilm biosynthesis of Priestia megaterium M1VB5 strain Muc Son Thanh Hoa paper mill

Introduction: Strain M1VB5, isolated from slime in paper machine pipes, is studied for its role in slime formation. This slime, comprised of microorganisms, binds and adheres to pipes, potentially leading to clogs, process inefficiencies, and machinery contamination. Methods: We investigated the biological characteristics and gene sequencing of M1VB5, focusing on its biofilm biosynthesis capabilities under varying sucrose concentrations, temperatures, pH levels, and time periods. Results: M1VB5 exhibited adaptability across a broad range of conditions, thriving at temperatures between 15-55°C and pH levels from 5 to 9, with up to 7% salinity tolerance. Capable of utilizing diverse carbon sources, M1VB5 efficiently biosynthesized extracellular enzymes, including CMCase, cellulase, xylanase, amylase, protease, and chitinase. Identified as Priestia megaterium (Gram-positive), it demonstrated significant biofilm formation, producing 36.4 g/L EPS and forming a 53.73 g/100g biofilm on PVC at a sucrose concentration of 100 g/L. Optimal biofilm production was observed at pH 8, with 28.40 g/L EPS and a biofilm mass of 59.61 g/100g PVC, and at 37°C, where EPS and biofilm weights reached 23.60 g/L and 63.78 g/100g PVC, respectively. The strain maintained steady biofilm production from day 4 to 14. Conclusion: M1VB5's versatile carbon source usage, wide temperature and pH range tolerance, and diverse enzyme production facilitate its growth and development. Its significant biofilm and EPS production capabilities contribute to its dominance in slime formations, offering insights for managing slime in industrial paper mill environments.