caa a22 4500 605498202 CHVBK 20210128100545.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s00253-015-6560-y doi (NATIONALLICENCE)springer-10.1007/s00253-015-6560-y Saccharomyces cerevisiae EC-1118 enhances the survivability of probiotic Lactobacillus rhamnosus HN001 in an acidic environment [Elektronische Daten] [Phebe Lim, Mingzhan Toh, Shao Liu] The present study attempted to partially characterize and elucidate the viability-enhancing effect of a yeast strain Saccharomyces cerevisiae EC-1118 on a probiotic strain Lactobacillus rhamnosus HN001 under acidic conditions using a model system (non-growing cells). The yeast was found to significantly enhance (P < 0.05) the viability of the probiotic strain under acidic conditions (pH2.5 to 4.0) by 2 to 4 log cycles, and the viability-enhancing effects were observed to be influenced by pH, and probiotic and yeast concentrations. Microscopic observation and co-aggregation assay revealed that the viability-enhancing effect of the yeast could be attributed to direct cell-cell contact co-aggregation mediated by yeast cell surface and/or cell wall components or metabolites. Furthermore, non-viable yeast cells killed by thermal means were observed to enhance the viability of the probiotic strain as well, suggesting that the surface and/or cell wall component(s) of the yeast contributing to co-aggregation was heat-stable. Cell-free yeast supernatant was also found to enhance the viability of the probiotic strain, indicating the presence of protective yeast metabolite(s) in the supernatant. These findings laid the foundation for further understanding of the mechanism(s) involved and for developing novel microbial starter cultures possibly without the use of live yeast for ambient-stable high-moisture probiotic foods. Springer-Verlag Berlin Heidelberg, 2015 Lactobacillus rhamnosus nationallicence Saccharomyces cerevisiae nationallicence Acidic environment nationallicence Viability nationallicence Co-aggregation nationallicence Metabolites nationallicence Lim Phebe Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singapore aut Toh Mingzhan Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singapore aut Liu Shao Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singapore aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/16(2015-08-01), 6803-6811 0175-7598 99:16<6803 2015 99 253 https://doi.org/10.1007/s00253-015-6560-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-015-6560-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lim Phebe Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singapore aut NATIONALLICENCE 700 1- Toh Mingzhan Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singapore aut NATIONALLICENCE 700 1- Liu Shao Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore, Singapore aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/16(2015-08-01), 6803-6811 0175-7598 99:16<6803 2015 99 253