Open AccessImpact of spray‐drying on the pili of Lactobacillus rhamnosus GG
Author(s) -
Kiekens Shari,
Vandenheuvel Dieter,
Broeckx Géraldine,
Claes Ingmar,
Allonsius Camille,
De Boeck Ilke,
Thys Sofie,
Timmermans JeanPierre,
Kiekens Filip,
Lebeer Sarah
Publication year - 2019
Publication title -
microbial biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.287
H-Index - 74
ISSN - 1751-7915
DOI - 10.1111/1751-7915.13426
Subject(s) - lactobacillus rhamnosus , probiotic , spray drying , microbiology and biotechnology , microorganism , food science , pilus , bacteria , viability assay , lactobacillus , mucus , chemistry , biology , in vitro , fermentation , biochemistry , escherichia coli , chromatography , gene , ecology , genetics
Summary The preservation of the viability of microorganisms in probiotic formulations is the most important parameter ensuring the adequate concentration of live microorganisms at the time of administration. The formulation and processing techniques used to produce these probiotic formulations can influence the preservation of the microbial viability. However, it is also required that the bacteria maintain their key probiotic capacities during processing, formulation and shelf life. In this study, we investigated the impact of spray‐drying on different cell wall properties of the model probiotic strain Lactobacillus rhamnosus GG , including its adherence to intestinal epithelial cells. The dltD gene knock‐out mutant, L. rhamnosus GG CMPG 5540, displaying modified cell wall lipoteichoic acids, showed significantly increased colony‐forming units after spray‐drying and subsequent storage under standard conditions compared to wild‐type L. rhamnosus GG . In contrast, disruption of the biosynthesis of exopolysaccharides or pili expression did not impact survival. However, spray‐drying did significantly affect the adherence capacity of L. rhamnosus GG . Scanning electron microscopy confirmed that the pili, key surface factors for adherence to intestinal cells and mucus, were sheared off during the spray‐drying process. These data thus highlight that both the functionality and viability of probiotics should be assessed during the spray‐drying process and subsequent storage.