Biodiversidad, producción de bacteriocinas, seguridad y propiedades funcionales de cepas bacterianas aisladas de leche materna

Resumen

Three weekly samples of breast milk were taken from a single donor during 28 weeks. The 84 samples obtained were plate count in different media. 578 bacterial strains were isolated. The production of antimicrobial substances was studied by spot-on-a-lawn and agar well assays. The 101 strains that produced bacteriocin-like substances were identified using 16S rDNA. The strains belonged to only 3 phyla and 11 genera. According to their functional characteristics (growth on bile /aesculin agar, at high salt concentration and low pH) and safety (lack of hemolytic and DNAase activities, and absence of antimicrobial resistance genes), 13 strains were selected for further studies. The bacterial diversity of milk samples was studied by high-throughput sequencing analysis. Streptococcus was the main bacterial group detected in many of the milk samples. Other relevant bacterial groups detected were Staphylococcus, Rothia or Veillonella.