Lactic acid bacteria isolated from Chinese traditional fermented milk as novel probiotic strains and their potential therapeutic applications

Mohamedelfatieh Ismael; Yaxin Gu; Yanlong Cui; Tao Wang; Fangfang Yue; Qin Yantin; Xin Lü

doi:10.1007/s13205-022-03403-z

Lactic acid bacteria isolated from Chinese traditional fermented milk as novel probiotic strains and their potential therapeutic applications

3 Biotech. 2022 Dec;12(12):337. doi: 10.1007/s13205-022-03403-z. Epub 2022 Nov 2.

Authors

Mohamedelfatieh Ismael^{1

2}, Yaxin Gu^{1

3}, Yanlong Cui¹, Tao Wang¹, Fangfang Yue¹, Qin Yantin¹, Xin Lü¹

Affiliations

¹ College of Food Science and Engineering, Northwest A&F University, Yangling, 712100 China.
² Sudanese Standard and Metrology Organization, 13573 Khartoum, Sudan.
³ College of Food Science, China Agricultural University, Beijing, China.

Abstract

Lactic acid bacteria (LAB) are believed to have health-promoting properties to the host and can be used in therapeutics interventions; intriguingly, they have the property to produce bio-preservatives substances. Therefore, this study aimed to mine probiotics and evaluate their safety, functional properties, and cholesterol-lowering capability. Seven potential probiotic strains were compared from 56 LAB strains isolated from traditional Chinese fermented milk. The results showed that all tested strains are tolerant to gastric acidity (45.5-83.26) and bile salts (11.92-92.91%) and have antibacterial activity against Staphylococcus aureus ATCC25923 and Escherichia coli ATCC25922. Likewise, it lowered the cholesterol levels in vitro by live cells (26.57-45.76%) and dead cells (29.53-50.97%) with remarkable aggregation ability (13.8-43.71%). Antioxidant properties and produce short chain fatty acids (SCFAs) were strain-dependent features. Upon assessment of the safety, Enterococcus faecium NWAFU-BIO-AS14 exhibited virulence factors genes (VFs) of (mur-2ed, odc, and tet(K)) and + hemolysis activity. While Enterococcus faecium NWAFU-BIO-A-B24 and Limosilactobacillus fermentum NWAFU-BIO-B-S6 have VFs of (odc, vanC2, and ant(6)-Ia). Limosilactobacillus fermentum NWAFU-BIO-D-B2 has only (odc). Thus, they are not considered as safe probiotics. In contrast, Lactiplantibacillus plantarum NWAFU-BIO-BS29, Companilactobacillus crustorum NWAFU-BIO-AS16, and Lactobacillus gallinarum NWAFU-BIO-D-S7 are the safest and best strains, respectively, due to the absence of 16 VFs and their sensitivity to antibiotics such as kanamycin, erythromycin, tetracycline, gentamycin, vancomycin, streptomycin, chloramphenicol, and ampicillin. Accordingly, these strains have a high potentiality to be used as starter cultures or safely applied as perfect probiotics in functionals food and feed.

Supplementary information: The online version contains supplementary material available at 10.1007/s13205-022-03403-z.

Keywords: Antibiotic resistance; Antioxidant; Cholesterol-lowering; Hemolytic activity; Lactic acid bacteria; Probiotics; SCFAs; Virulence genes.

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