Abstract #402

# 402
Interaction of lactic acid bacteria with MFGM phospholipids – Surface adherence.
Joana Ortega-Anaya*1, Israel García-Cano1, Diana Rocha-Mendoza1, Rafael Jiménez-Flores1, 1The Ohio State University, Colulmbus, OH.

It is widely known that probiotic lactic acid bacteria attaches to membranes of intestinal cells triggering signals that result in beneficial effects to human health. Strong evidence also indicates that milk phospholipids (PLs) derived from the MFGM have an impact in lowering cholesterol, improving anti-inflammatory, chemotherapeutic and anti-neurodegenerative responses. However, little is known about the role of milk PLs once they come in contact with lactic acid bacteria arising many questions: Do they bind intact PL molecules? Do they utilize them, producing metabolites that could be further absorbed by human intestine? In this work, we studied the primary surface interaction and adherence of 5 strains of lactic acid bacteria with PL from the MFGM. We tested L. casei, L. pentosus, L. plantarum, P. acidilactici, and P. lolli which have been proved by our research group to grow in a media enriched with milk PLs (0.5% wt/vol). We prepared supported lipid bilayers (SBL) in a SiO2 surface using a specific mixture of milk PLs kindly donated by Fonterra Co-Op, NZ (1.5 mg/mL in PBS buffer pH 7.4). Interaction studies were investigated using a quartz crystal microbalance with dissipation (QCM-D) which measures in real time, changes in the resonance frequency (ΔF) and dissipation energy (ΔD) of acoustic waves when a layer of molecules (milk PLs and cells) is adsorbed on the active surface (SiO2) of the sensor. Our results indicate that L. pentosus and plantarum bind irreversibly to milk PLs at different stages of cell growth. Additionally, we observed and characterized the mass loss of PL molecules from the supported bilayer indicating that the bacterial cells utilize and metabolize them to further produce metabolites with different bioactivities. In conclusion, our experimental work shows that some strains of lactic acid bacteria such as Lactobacillus pentosus and L. plantarum unequivocally bind to phospholipids isolated from bovine MFGM. This information is helpful in understanding and modeling the phospholipid–bacterial response and behavior in either the intestinal lumen or in fermented dairy products.

Key Words: lactic acid bacteria adherence, milk phospholipids, quartz crystal microbalance