Functional properties of autochthonous lactic acid bacteria starter cultures for plant-based food fermentation

Lactic acid bacteria (LAB) that are autochthonous to the raw material are commonly recognised as the most suitable bacteria for starter cultures for fermentation. In this study, 172 LAB isolated from cereals and pulses were genetically characterised, and 37 of these were whole genome sequenced. Twenty-four LAB were selected for technological characterization. Screening assays were set up to determine the ability of these isolates to produce exopolysaccharides and hydrolyse proteins, reduce phytic acid, and ferment various carbohydrate substrates. The ability to grow and acidify was tested in flour-like media and flour slurries. Chromatographic methods were applied to quantify carbohydrates and organic acids before and after fermentation. The 24 isolates belonging to 8 different species of LAB exhibited a diverse combination of important functional and technological properties. Isolates with the ability to rapidly reduce pH, proliferate at a high rate, produce large amounts of organic acids and metabolise citrate were found among the 24 candidates. The isolates displayed different combinations of carbohydrate fermentation ability, proteolytic activity, phytase activity, and formation of mucoid and threading colonies. Several isolates exhibited one or more desirable traits, with one expressing all the desired properties tested here; Lpb. paraplantarum JP51. These results provide insights into the potential of these isolates for developing autochthonous starter cultures.