Biopreservation potential of Carnobacterium maltaromaticum strains against Listeria monocytogenes in plant-based cheese analogs

• Two strains of C. maltaromaticum inhibited a wide range of Listeria spp. strains. • Only one strain produced an inhibitory substance in agar diffusion assay. • Both strains inhibited L. monocytogenes in a plant-based cheese analog model. • C. maltaromaticum did not significantly affect the microbial diversity of the analog. • Safety assessment confirmed the biopreservation potential of the strains. Over the past decades, growing health, ethical, and environmental concerns surrounding food consumption have driven the increasing popularity of plant-based diets. However, recent cases of listeriosis have been associated with the consumption of plant-based cheese analogs. In milk-based cheeses, biopreservation using adjunct cultures such as Carnobacterium maltaromaticum is a well-established strategy to inhibit the growth of Listeria monocytogenes . This study explores the application of this approach to cashew-based cheese analogs by assessing the anti- L. monocytogenes potential of two C. maltaromaticum strains, F88 and P13A1, in model productions. Metabarcoding analyses revealed that the addition of C. maltaromaticum P13A1 did not significantly alter the microbial community structure, despite its ability to grow and persist in the model analogs. Genomic and phenotypic assessments confirmed the safety of both strains, supporting their suitability for biopreservation purposes. Co-culture experiments in broth showed that both strains inhibited a broad spectrum of Listeria spp. In model analogs, both strains similarly limited the growth of Listeria monocytogenes EGDe, even though strain F88 is bacteriocinogenic and strain P13A1 is not. The observed anti- Listeria activity was lower than the levels typically reported in milk-based cheeses, likely reflecting compositional differences between dairy and plant-based matrices. These findings suggest that biopreservation strategies for plant-based cheese analogs should take into account the specific physicochemical and microbial characteristics of these novel food systems as early as the strain selection stage.