Isolation, identification, and in vitro probiotic characterization of forty novel Bifidobacterium strains from neonatal feces in Erzurum province, Türkiye.

BACKGROUND: Neonatal feces are one of the most important sources for probiotic isolation. The purpose of this study was the isolation and identification of Bifidobacterium spp. from neonatal feces and the evaluation of in vitro probiotic properties of strains including safety tests. RESULTS: A total of 40 isolates were obtained from 14 healthy newborns' feces in Erzurum province, Türkiye. By their rep-PCR patterns and 16S rRNA gene sequences, isolates were identified as 26 Bifidobacterium breve and 14 Bifidobacterium longum. Fifteen of the isolates tolerated bile salts and showed high resistance to simulated gastric juice. Isolates exhibited varying rates of auto-aggregation and hydrophobicity. In addition, most of the isolates displayed antibacterial activity against Escherichia coli O157:H7, Staphylococcus aureus ATCC 29213, Salmonella Typhimurium RSHMB 95091, and Pseudomonas aeruginosa ATCC 9027. However, only one strain showed bile salt hydrolase activity and two strains showed the ability to produce H2O2. Bifidobacterium strains were generally sensitive to the tested antibiotics and lacked kanamycin, gentamicin, and streptomycin resistance genes, and hemolytic and DNAse activities. On the other hand, it was determined that five strains had various virulence genes including gelE, esp, efaAfs, hyl, and ace. CONCLUSION: Results of the present study suggested that B. longum BH28, B. breve BH4 and B. breve BH5 strains have the potential as probiotic candidates for further studies. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Evaluation of Spreadable Kefir Produced from Different Milks in Terms of Some Quality Criteria.

Kefir, which has many beneficial effects on health, is one of the most consumed fermented milk products worldwide. It is important to increase consumption of the fermented product for public health. In this study, it was aimed to increase the beneficial effects of kefir on public health. Therefore, kefirs produced from different types of milk (cow, buffalo, sheep, and goat) were concentrated, and obtained spreadable kefir samples were investigated in terms of their microbiological characteristic (lactic bacilli, lactic cocci, yeasts and moulds, total bacteria, and coliform bacteria), benzoic acid content, physicochemical properties (fat, total solid, ash content, acidity, pH, syneresis, viscosity, colour, and rheological properties), and sensory characteristic. It was determined that APC, lactic bacilli, lactic cocci, and yeast counts of the concentrated kefir samples changed between 6.90 and 8.64, 6.89 and 8.61, 7.42 and 8.72, and 2.17 and 5.39 log CFU/g, respectively, during storage. Mould and coliform bacteria were not detected in the samples. The concentrated kefir samples contained benzoic acid in the range of 18.30-119.58 mg/L. Results from this study showed that type of milk caused differences on APC, lactic bacilli, lactic cocci and yeast count, total solids, ash, fat, acidity, pH, syneresis, colour, viscosity and rheological parameters, and benzoic acid content. In addition, milk type affected sensory properties of the kefirs. Concentrated kefirs produced from cow and buffalo milk were the most liked by panellists. Finally, it was determined that concentrated kefir was favoured as a new product by most of the panellists.