Abstract #M99

# M99
Screening, identification, and analysis of lactic acid bacterial strains grown in milk phospholipids-supplemented minimal medium and MRS medium.
L. Zhang*1, I. García-Cano1, D. Rocha-Mendoza1, J. Ortega-Anaya1, R. Jiménez-Flores1, 1Department of Food Science and Technology, The Ohio State University, Columbus, OH.

Milk phospholipids (MPLs) have gained people’s attention due to their nutritional and functional properties like reducing gastrointestinal infection and supporting neurological development. They are gradually tested as ingredients for food application and human consumption. Meanwhile, lactic acid bacteria (LAB) are important components of human gut microbiome and they are commonly used in fermented dairy products. However, little is known about the effects of MPLs on the growth of LAB. The aim of this study was to select LAB strains that can grow relatively well in medium supplemented with MPLs, to sort LAB for future MPLs-LAB studies and potential applications. One hundred and 37 strains of LAB from our culture collection (OSU library) were grown in modified minimal medium (MM) and also in MRS media with 0.5% MPLs added. Strains with relatively high optical density (OD600nm) and high maximum growth rates (μmmax) were selected and identified by 16s rRNA sequencing. Further analysis included resistance to antibiotic, pH, bile salts, hydrophobicity, auto-aggregation, and virulence factors were conducted to prove their probiotic potential. After screening and analysis, it was found out that 6 strains having relatively high OD600nm and high μmmax in MM media supplemented with MPLs are P. pentosaceus, L. pentosus, L. helveticus, L. rhamnosus, L. gasseri and L. reuteri. Their growth kinetics changed with the presence of MPLs. Interestingly, they all had higher maximum growth rates and shorter lag phase but lower optical density growing in MPLs supplemented MRS medium than in MRS medium. However, they both had higher maximum growth rates and higher optical density in MPLs supplemented MM medium than just MM medium. This study suggests that certain LAB grew better in the presence of MPLs, and they might be used in combination with MPLs for future research and applications.

Key Words: milk phospholipids, lactic acid bacteria, kinetic growth