Inter-species differences in maximum specific growth rates and cell yields of bifidobacteria cultured on oligosaccharides and other simple carbohydrate sources

The abilities of seven bifidobacterial isolates ( Bifidobacterium adolescentis , B. bifidum (two strains), B. catenulatum , B. infantis , B. longum , B. pseudolongum ) to utilize 15 different carbohydrate sources (eight oligosaccharide products, and a variety of monosaccharides and disaccharides) were studied, with regard to maximum specific growth rates and production of bacterial cell mass. Results showed that substrate utilization was highly variable and that considerable interspecies and interstrain differences existed. Galactooligosaccharides and oligofructose, with a low degree of polymerization, supported best growth of the test micro-organisms. In contrast, xylooligosaccharides and pyrodextrins were almost invariably poor bifidobacterial substrates. In many species, maximum specific growth rates and bacterial cell yields were higher on oligosaccharides compared to their monosaccharide constituents, particularly with respect to fructooligosaccharides. Bifidobacterium pseudolongum , B. longum and B. catenulatum were the most nutritionally versatile isolates studied in relation to the range of oligosaccharide products utilized, and the extent to which bacteria could grow on these substrates.