The main goal of the ALGPRO project is to design, develop and mechanistically investigate the ability of microalgal protein isolates obtained from at least three microalgal species (Chlorella, Galdieria sulphuraria and Arthrospira) as novel bio-preserving agents in microporous xero-scaffolds conveying different strains of living probiotic cells (Lactobacilli and/or Bifidobacteria species) of diversified cellular surface organisation. The mechanisms involved in the ability of microalgal proteins to promote the resistance of the living probiotic cells under diverse extrinsic stressors associated with processing and storage, i.e., thermal, osmotic or oxidative shock, will be studied comparatively to the well-studied milk proteins i.e., whey protein isolate and sodium caseinate. In addition, the interactions between the colloidal transformation (disintegration and release profile) of the conveying xero-vehicles and the sub-lethality of the Lactobacilli cells under simulated (static or semi-dynamic) in vitro digestion conditions will be investigated. Furthermore, the Lactobacilli/ Bifidobacteria cell adhesion biophysics using diverse adhesion models (co-culture cell model vs pig intestinal epithelium), will be part of the investigations. Finally, the growth kinetics and volatilome changes under anaerobic conditions using a synthetic microbial gut system spiked with the dialysed intestinal digesta will also be tracked down.