Enhancement of bifidobacteria survival by Williopsis saturnus var. saturnus in milk

Abstract

The viability of three strains of probiotic Bifidobacterium lactis that were inoculated into UHT milk was examined with and without the presence of the yeast, Williopsis saturnus var. saturnus NCYC 22, in polypropylene tubes at 30 C. The B. lactis viable cell count for strains HN019 and BB-12 remained above 6.0 Log cfu/ml, while strain B94 had 5.7 Log cfu/ml after six weeks of incubation in the presence of the co-inoculated yeast. Incubating the bifidus milk without added yeast under anaerobic condition did not improve the survival of B. lactis HN019, indicating that oxygen removal may not be responsible for W. saturnus NCYC 22's viability enhancing property. The addition of yeast supernatant or non-viable yeast also did not show any stabilising effects, suggesting that physical contact and/or interaction between viable W. saturnus and B. lactis plays an important role in sustaining the viability of the probiotic. W. saturnus NCYC 22 could increase the survival of B. lactis in bifidus milk under ambient temperature regardless of the initial concentration of yeast cells inoculated due to yeast growth. This study demonstrated the viability enhancing effect of viable W. saturnus NCYC 22 on B. lactis HN019, which could help towards extending the shelf-life of dairy beverages containing probiotic bifidobacteria.

Impact of coculturingBifidobacterium animalissubsp.lactisHN019 with yeasts on microbial viability and metabolite formation

“…Enumeration of B. lactis and yeasts was performed by the plate count method according to the method of Yeo et al (2016). pH measurements were done using a 713 pH meter (Metrohm, Herisau, Switzerland) that was calibrated with pH 4 and 7 buffers (Merck).…”

“…The yeast also prolonged the survival of the bifidobacteria in fermented milk during cold storage. Yeo et al (2016) reported that the viability of three commercial Bifidobacterium animalis subsp. lactis strains in unfermented milk was enhanced by Williopsis saturnus throughout long-term incubation at 30°C.…”

“…Yeo et al . () reported that the viability of three commercial Bifidobacterium animalis subsp. lactis strains in unfermented milk was enhanced by Williopsis saturnus throughout long‐term incubation at 30°C.…”

Avaliação da interação entre leveduras isoladas de kombucha e bactérias probióticas

“…Ainda Yeo e colaboradores demonstra que a levedura Williopsis saturnus subsp. saturnus NCYC22 possui a capacidade e aprimorar a manutenção da viabilidade de bactérias probióticas do gênero Bifidobacterium, incluindo a HN019 [67]. Alguns fatores são importantes na determinação do potencial probiótico de determinada linhagem de microrganismo, como a autoagregação, hidrofobicidade, capacidade de formação de biofilme e segurança quanto a sua utilização [68].…”

“…lactis HN019, linhagem autorizada e reconhecida no Brasil como probiótica, pela Agência Nacional de Vigilância Sanitária (ANVISA). Apesar de ser uma linhagem que resiste pouco à presença de oxigênio, optou-se por realizar a co-cultura em aerobiose, uma vez que as leveduras podem favorecer que o micro ecossistema mantenha a viabilidade das bactérias, como demonstrado por Yeo e colaboradores [67], ressaltando que HN019 pode se beneficiar na presença da levedura Williopsis saturnus subsp. saturnus em leite fermentado, mantendo-se viável mesmo em aerobiose.…”