Lactobacilli and Moesziomyces Biosurfactants: Toward a Closed-Loop Approach for the Dairy Industry

Research on biosurfactants (BS) is consistently increasing in the past years, driven from their beneficial attributes over chemical surfactants. Lactobacilli (LAB) and yeast BS producers could prevail over the pathogenic strains, owing to their GRAS status, to broaden end-applications toward the food and pharmaceutical industries. However, the increased cost of production confers a bottleneck for the industrial manufacture. Hence, the exploitation of agro-industrial waste and by-products as fermentation supplements is currently on the spotlight. This study elaborates on the efficient production of lactobacilli and Moesziomyces BS via cheese whey (CW) bioprocessing. Subsequently, the obtained BS were individually assessed in fermented milk production using as starter culture the initial LAB strain used for BS synthesis. Physicochemical and microbiological assessment was performed during storage. Results indicated that LAB-BS addition increased the lactobacilli concentration, whereby mannosylerythritol lipids (MEL) inclusion showed a positive effect on syneresis. Aiming to develop a closed-loop process, for the first time, LAB cells after BS extraction were sequentially applied for sour milk production, demonstrating the ability for cell re-utilization. This study introduces a holistic and circular configuration that consolidates CW valorization for BS production, that are re-introduced in the food supply, to complement the resilience of the dairy industry.