Novel bifidobacteria strains isolated from non-conventional sources. Technological, antimicrobial and biological characterisation for their use as probiotics

SARQUIS, MA.; SIROLI, L.; MODESTO, M.; PATRIGNANI, F.; LANCIOTTI, R.; MATTARELLI, P.; REINHEIMER, J.; BURNS, P.

JOURNAL OF APPLIED MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2019 vol. 127 p. 1207 - 1218

1364-5072

Aim: to characterise four novel autochthonous bifidobacteria isolated from monkey faecesand a B. lactis strain isolated from chicken faeces by evaluating their technological andbiological/functional potential to be used as probiotics. Different stressors, including foodprocess parameters and storage, can affect their viability and functionality.Methods and Results: The resistance to frozen-storage, tolerance to lyophilisation andviability during storage, thermal, acidic and simulated gastric resistance, surfacehydrophobicity and antimicrobial activity against pathogens were studied. Bifidobacteriumlactis Bb12 and INL1 were used as reference strains.The results obtained demonstrated that the new isolates presented strain-dependent behaviour.Good results were obtained for thermal resistance, frozen-storage at -80°C and lyophilisedpowders maintained at 5°C. Cell viability during refrigerated storage was higher when thestrains were resuspended in milk at pH 5.0 than at 4.5. The surface hydrophobicity rangedbetween 7 and 98% depending on the strain. The simulated gastric resistance was improvedfor the strains incorporated in cheese. Regarding antimicrobial activity, bifidobacteria isolatedfrom monkey presented higher inhibitory capacity than the reference strains.Conclusion: this research provides a deeper insight into new strains of bifidobacteria isolatedfrom primates and chicken that have not been previously characterised for their potential usein dairy products and confirm the most robust stress tolerance of B. lactis.Significance and Impact of the Study: the possibility of expanding the availablebifidobacteria with the potential to be added to a probiotic food necessarily impliescharacterising them from different points of view, especially when considering unknownspecies. For monkey-isolates (which showed higher antimicrobial activity against pathogens),more in-depth knowledge is needed before applying strategies to improve their performance.On the contrary, the chicken-isolate B. lactis P32/1 showed similar behaviour to thereferences B. lactis strains; therefore, it could be considered as a potential probiotic candidate.