Efficacy of natamycin to reduce adhesion and biofilm formation of multispecies yeast biofilms on variable flow conditions.

This study evaluated the effectiveness of natamycin (NAT) on multispecies yeast biofilms isolated from ultrafiltration membranes in an apple juice processing industry. Biofilms were developed on stainless steel surfaces using 12° Brix apple juice under static (SC) and laminar flow (LF) conditions. NAT (0.01 mM) was applied from the beginning of the adhesion stage (NAT T0) and on 24-h-preformed biofilms (NAT T24). NAT T0 significantly reduced attachment and biofilm formation by ∼4-log₁₀ units after 48 h, while NAT T24 achieved reductions of 1.83 and 0.79-log₁₀ units in SC and LF, respectively. The overall reduction in total cell count was significantly more pronounced and consistent under SC. This highlights the importance of preventing initial adhesion for controlling biofilm development. Additionally, these findings underscore the importance of evaluating antimicrobial agents in dynamic flow conditions that closely mimic real-world applications.