Detalle de: Exploring the introduction of microbial ochratoxinases in lactic acid bacteria to enhance the safety of fermented plant-based beverages

Plant-based beverages are an alternative to traditional cow milk due to intolerances and allergies as well as for ethical and environmental concerns. Nonetheless, raw materials used in the manufacture of these products are at risk of mycotoxin contamination, being ochratoxin A (OTA) one of the mycotoxins detected. Recently, microbial enzymes have been described, some of them from microorganisms with GRAS ( Generally Recognized As Safe ) or QPS ( Qualified Presumption of Safety ) status, able to hydrolyze OTA into OTα, a much less-toxic compound. Since the use of lactic acid bacteria for the fermentation of plant-based beverages improved their nutritional and sensory properties, in this study lactic acid bacteria expressing microbial amidohydrolases from food safe microorganisms were used to ferment two plant-based beverages. Legume-based (soy) and cereal-based (oat) beverages artificially contaminated with OTA were fermented with three lactic acid bacteria strains ( Lactilactobacillus sakei DSM 15831, Limosilactobacillus fermentum INIA 584L, and Limosilactobacillus reuteri INIA P572) expressing OTA-hydrolyzing enzymes from Aspergillus niger ( An OTA) and Brevibacterium linens ( Bl OTA). The OTA added to both beverages was greatly degraded during fermentation with the lactic acid bacteria assayed. The OTA-detoxification activity observed could be related to the composition and pH of the fermented beverage. The lower pH achieved in fermented oat, probably due to its high fermentable carbohydrate composition, reduced OTA-degrading activity of An OTA ochratoxinase, mainly in Lactilactobacillus sakei . This first approach to explore OTA reduction in plant-based beverages paves the way for future applications of improved enzymes produced in food-grade expression systems.