New convenient defined media for [(35)S]methionine labelling and proteomic analyses of probiotic lactobacilli.
OBJECTIVE
To develop experimental conditions for efficient protein radiolabelling and two-dimensional (2D) polyacrylamide gel electrophoresis for investigation of stress proteomes of probiotic Lactobacillus spp.


RESULTS
Three chemically defined media (CDM) optimized from a commercial medium supported rapid growth of the probiotic Lactobacillus rhamnosus E97800, Lactobacillus brevis ATCC 8287 and Lactobacillus reuteri E97849, and a broad range of other lactic acid bacteria. These CDM allowed efficient protein radiolabelling, requiring as little as 200 mul of logarithmic culture and pulse-chase labelling of 20 min to detect c. 300 distinct protein spots in a mini-scale 2D-gel. Proteins including DnaK, GroEL and ClpATPases were identified from the 2D-gels by immunoblotting.


CONCLUSIONS
Radiolabelling coupled with 2D gel electrophoresis provides a sensitive means to monitor changes in protein synthesis rates in probistic lactobacilli.


CONCLUSIONS
Efficient tools for proteomic analyses of probiotic Lactobacillus were developed and applied for stress-response studies.
Division of Microbiology and Epidemiology, Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
K
K
Savijoki
A
A
Suokko
A
A
Palva
P
P
Varmanen
D000251:Adenosine Triphosphatases / Q000032:analysis / Q000096:biosynthesis; D001426:Bacterial Proteins / Q000032:analysis* / Q000096:biosynthesis; D018834:Chaperonin 60 / Q000032:analysis / Q000096:biosynthesis; D003470:Culture Media / Q000737:chemistry; D015180:Electrophoresis, Gel, Two-Dimensional; D049071:Endopeptidase Clp / Q000032:analysis / Q000096:biosynthesis; D006358:Hot Temperature; D007778:Lactobacillus / Q000254:growth & development* / Q000378:metabolism; D008715:Methionine; D019936:Probiotics / Q000378:metabolism*; D020543:Proteome / Q000032:analysis* / Q000096:biosynthesis; D013194:Staining and Labeling; D013462:Sulfur Radioisotopes
D001426:Bacterial Proteins; D018834:Chaperonin 60; D003470:Culture Media; D020543:Proteome; D013462:Sulfur Radioisotopes; D008715:Methionine; D049071:Endopeptidase Clp; D000251:Adenosine Triphosphatases