Identification of safe putative probiotics from various food products

• Published in: Folia microbiologica Vol. 69; no. 5; pp. 1053 - 1068
• Main Authors: Arellano, Karina, Lim, Juwhan, Bucheli, Jorge Enrique Vazquez, Park, Haryung, Todorov, Svetoslav Dimitrov, Holzapfel, Wilhelm Heinrich
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-10-2024; Springer Nature B.V
• Subjects: Adhesion; Animals; Antibiotic resistance; Applied Microbiology; Bacteria; Bacterial Adhesion; Biomedical and Life Sciences; DNA, Bacterial - genetics; Environmental Engineering/Biotechnology; Fermented food; Food; Food Microbiology; Food products; Food selection; Food sources; Gastrointestinal system; Gastrointestinal tract; Hydrophobicity; Immunology; In vitro methods and tests; Intestine; Isolation media; Kimchi; Lactic acid; Lactic acid bacteria; Lactobacillales - classification; Lactobacillales - genetics; Lactobacillales - isolation & purification; Lactobacillales - metabolism; Life Sciences; Microbiology; Milk; Original Article; Phylogeny; Probiotics; Probiotics - isolation & purification; RNA, Ribosomal, 16S - genetics; rRNA 16S; Safety; Saliva; Selective media; Sequence analysis; Sequence Analysis, DNA; Strains (organisms); Zeta potential; Lactic acid bacteria; Safety; Viability; Adhesion
• ISSN: 0015-5632; 1874-9356; 1874-9356
• DOI: 10.1007/s12223-024-01142-7

The objective of this study was to isolate, identify, and assess the safety and functionality in vitro of putative probiotic bacterial strains. Isolation procedures were based on standard methods using elective and selective media. The isolates were identified by comparative 16S rRNA sequencing analysis while their safety was determined according to the safety tests recommended by the FAO/WHO such as antibiotic resistance, hemolysin, and biogenic amine production. Most of the isolates did not pass the in vitro safety tests; therefore, only
Lactiplantibacillus plantarum
(from ant intestine and cheese),
Lacticaseibacillus paracasei
(from goat milk and
kimchi
),
Enterococcus faecium
(from chili
doenjang
and vegetables with
kimchi
ingredients),
Limosilactobacillus fermentum
(from saliva), and
Companilactobacillus alimentarius
(from
kimchi
) were identified and selected for further studies. The isolates were further differentiated by rep-PCR and identified to the strain level by genotypic (16S rRNA) and phenotypic (Gen III) approaches. Subsequently, the strain tolerance to acid and bile was evaluated resulting in good viability after simulated gastrointestinal tract passage. Adhesion to mucin in vitro and the presence of
mub
,
mapA
, and
ef-tu
genes confirmed the adhesive potential of the strains and the results of features associated with adhesion such as hydrophobicity and zeta potential extended the insights. This study reflects the importance of fermented and non-fermented food products as a promising source of lactic acid bacteria with potential probiotic properties. Additionally, it aims to highlight the challenges associated with the selection of safe strains, which often fail in the in vitro tests, thus hindering the possibilities of “uncovering” novel and safe probiotic strains.