Mixed-Species Biofilm Formation by Direct Cell-Cell Contact between Brewing Yeasts and Lactic Acid Bacteria

Screening of lactic acid bacteria that can form mixed-species biofilm with Saccharomyces cerevisiae

“…1,2) To assay biofilm formation, stationary phase LAB or yeast cultures were inoculated into fresh YPD at the dilution rate of 1:100 in monoculture. While for co-culture, both stationary phase cultures of LAB and yeast were inoculated into fresh YPD at the dilution rate of 1:200, respectively.…”

“…scanning electron microscopy (SEM) observations of biofilms were performed as described in the previous studies. 1,18) Coverslips with biofilm were washed by immersing in 0.1 M sodium phosphate buffer (pH 7.0) and fixed with 2% glutaraldehyde and with 2% osmium tetra-oxide, and dehydrated with increasing ethanol-acetone concentrations. Drying was then performed with a critical point dryer HCP-2 (Hitachi High-Technologies, Tokyo), and the samples were metal coated with an ion sputter E-1010 (Hitachi High-Technologies).…”

“…We found only a few strains that form lower amount of mixed-species biofilm with budding yeast in these isolated strains. 1) In this paper, we screened the LABs that can form mixed-species biofilm with S. cerevisiae from various stock cultures. The origins of the LABs used in this study were various sources including some traditional fermented foods, and some of them were type strains in various culture collections.…”

“…We previously reported that Lactobacillus plantarum ML11-11 isolated from Fukuyama pot vinegar and Saccharomyces cerevisiae remarkably formed mixed-species biofilm with direct cell-to-cell contact, 1) and also reported that L. plantarum ML11-11 had significant ability to make co-aggregation with yeast S. cerevisiae and the co-aggregation played an important role in their mixed-species biofilm formation. 2) We considered that the formation of a biofilm, a microbial community on the solid-liquid interface, [3][4][5][6] would be important in the traditional fermentation processes that start from solid biomaterials.…”

“…2) We considered that the formation of a biofilm, a microbial community on the solid-liquid interface, [3][4][5][6] would be important in the traditional fermentation processes that start from solid biomaterials. 1,[7][8][9] Coexistence and symbiosis of yeasts and lactic acid bacteria (LAB) in traditional fermentation are well known. [7][8][9][10] There are a few pioneering studies on the co-aggregative interactions between yeasts and LABs.…”