title: Lactobacillus casei Low-Temperature, Dairy-Associated Proteome Promotes Persistence in the Mammalian Digestive Tract.
abstract: We found that incubation of probiotic Lactobacillus casei BL23 in milk at 4 °C prior to ingestion increased its survival in the mammalian digestive tract. To investigate the specific molecular adaptations of L. casei to milk, we used tandem mass spectrometry to compare proteins produced by L. casei BL23 at 4 °C in milk to those in exponential and stationary phase cells in laboratory culture medium at either 37 or 4 °C. These comparisons revealed a core of expressed L. casei proteins as well as proteins produced in either a growth-phase or temperature-specific manner. In total, 205 L. casei proteins were uniquely expressed or detected in higher abundance specifically as a result of incubation in milk and included an over-representation of proteins for cell surface modification, fatty acid metabolism, amino acid transport and metabolism, and inorganic ion transport. Genes for DltD (d-alanine transfer protein), FabH (3-oxoacyl-ACP synthase), RecA (recombinase A), and Sod (superoxide dismutase) were targeted for inactivation. The competitive fitness of the mutants was altered in the mouse intestine compared with wild-type cells. These results show that the food matrix can have a profound influence on dietary (probiotic) bacteria and their functional significance in the mammalian gut.
authors.forename: Bokyung
authors.initials: B
authors.lastname: Lee
authors.forename: Sybille
authors.initials: S
authors.lastname: Tachon
authors.affiliation: ‡Proteomics Core Facility, Genome Center, University of California, 451 East Health Sciences Drive, Davis, California 95616, United States.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Eigenheer
authors.affiliation: ‡Proteomics Core Facility, Genome Center, University of California, 451 East Health Sciences Drive, Davis, California 95616, United States.
authors.forename: Brett S
authors.initials: BS
authors.lastname: Phinney
authors.forename: Maria L
authors.initials: ML
authors.lastname: Marco
mesh_terms: D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase / Q000235:genetics / Q000378:metabolism; D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002853:Chromatography, Liquid; D003080:Cold Temperature; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology*; D007780:Lacticaseibacillus casei / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D008807:Mice, Inbred BALB C; D008892:Milk / Q000737:chemistry; D009154:Mutation; D019936:Probiotics; D020543:Proteome / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D011938:Rec A Recombinases / Q000235:genetics / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D013869:Thiolester Hydrolases / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D020543:Proteome; D013482:Superoxide Dismutase; D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase; D011938:Rec A Recombinases; C408973:DltD protein, bacteria; D013869:Thiolester Hydrolases
keywords: IBD; Lactobacillus casei; dairy; intestinal fitness; low temperature; mass spectrometry; microbiota; milk; probiotics; proteomics