Versatile <i>Lactococcus lactis</i> strains improve texture in both fermented milk and soybean matrices
Vera Kuzina Poulsen, Elahe Ghanei Moghadam, Stjepan Krešimir Kračun, Birgit Albrecht Svendsen, Wioleta Marta Nielsen, Gunnar Øregaard, Anders Krarup
Abstract
Lactic acid bacteria (LAB) have long been used to extend the shelf life and improve the taste and texture of fermented milk. In this study, we investigated the texturing potential of LAB in plant-based fermentation by high-throughput screening of 1232 Lactococcus lactis strains for texture in milk and liquid soybean matrices. We found that most strains with texturing abilities in fermented milk were also capable of enhancing the texture in fermented soybean, despite the large differences in composition of the two matrices. Exocellular polysaccharide production is believed to contribute positively to fermented milk and plant-base texture. It appeared as if it was the properties of the polysaccharides rather than their protein interaction partners that were responsible for the enhanced texture in both matrices. We mined whole genome sequences of texturing strains for polysaccharide biosynthesis (eps) gene clusters. The comparative genomics approach revealed 10 texturing strains with novel eps gene clusters. Currently, the relationship between the novel genes and their functionality in milk and plant matrices is unknown.