Development of a novel lactic acid bacteria starter culture approach: From insect microbiome to plant-based fermentations

Lactic acid bacteria (LAB) are a broad group of gram-positive bacteria that have actively been used worldwide in food productions due to their nutritional, technological, bioprotection and flavour-related characteristics, which define them as powerful biological tools to be used in fermented food applications.

LAB are ubiquitous in nature and some species have been found in fructose-rich niches, such as insect microbiomes. Twenty-eight LAB species were isolated from Apis mellifera, Bombus spp. and Andrena nigroaenea insect sources. Lactococcus lactis was the most widespread species in all insect species. A phenotypical characterization analysis based on carbohydrate metabolism, subproduct and acid production, pectinolytic activity, citrate uptake, phytate degradation and diacetyl production was carried out.

Based on this analysis, two strains belonging to Leuconostoc pseudomesenteroides and L.lactis species were found to be the most suitable strains for use in common food plant matrices. The former showed an ability to significantly catabolize raffinose, maltose and citrate, which are present in soy beverages, while the latter was able to produce high concentrations of diacetyl and lactic acid, which are relevant for the generation of plant dairy alternatives, and noticeably degraded phytic acid, pectin and sucrose mostly found in bean, cereal and fruit-based plant matrices.