Identification of prebiotic fructooligosaccharide metabolism in Lactobacillus plantarum WCFS1 through microarrays.
Short-chain fructooligosaccharides (scFOS) and other prebiotics are used to selectively stimulate the growth and activity of lactobacilli and bifidobacteria in the colon. However, there is little information on the mechanisms whereby prebiotics exert their specific effects upon such microorganisms. To study the genomic basis of scFOS metabolism in Lactobacillus plantarum WCFS1, two-color microarrays were used to screen for differentially expressed genes when grown on scFOS compared to glucose (control). A significant up-regulation (8- to 60-fold) was observed with a set of only five genes located in a single locus and predicted to encode a sucrose phosphoenolpyruvate transport system (PTS), a beta-fructofuranosidase, a fructokinase, an alpha-glucosidase, and a sucrose operon repressor. Several other genes were slightly overexpressed, including pyruvate dehydrogenase. For the latter, no detectable activity in L. plantarum under various growth conditions has been previously reported. A mannose-PTS likely to encode glucose uptake was 50-fold down-regulated as well as, to a lower extent, other PTSs. Chemical analysis of the different moieties of scFOS that were depleted in the growth medium revealed that the trisaccharide 1-kestose present in scFOS was preferentially utilized, in comparison with the tetrasaccharide nystose and the pentasaccharide fructofuranosylnystose. The main end products of scFOS fermentation were lactate and acetate. This is the first example in lactobacilli of the association of a sucrose PTS and a beta-fructofuranosidase that could be used for scFOS degradation.
Saulnier
Delphine M A
DM
Food Microbial Sciences Unit, School of Food Biosciences, The University of Reading, Box 226, Reading RG6 6AP, United Kingdom. d.m.a.saulnier@reading.ac.uk
Molenaar
Douwe
D
de Vos
Willem M
WM
Gibson
Glenn R
GR
Kolida
Sofia
S
D019342:Acetic Acid / Q000378:metabolism; D000222:Adaptation, Physiological; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D004798:Enzymes / Q000096:biosynthesis / Q000235:genetics; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D048191:Lactiplantibacillus plantarum / Q000235:genetics* / Q000378:metabolism*; D008954:Models, Biological; D020411:Oligonucleotide Array Sequence Analysis; D009844:Oligosaccharides / Q000378:metabolism*; D012329:RNA, Bacterial / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics
D001426:Bacterial Proteins; D004798:Enzymes; D009844:Oligosaccharides; D012329:RNA, Bacterial; D012333:RNA, Messenger; C116580:fructooligosaccharide; D019344:Lactic Acid; D005947:Glucose; D019342:Acetic Acid