INTERSPECIES 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 adole scentis, B. bifidum (two strains), B. catenulatum, B, infantis, B. lon gum, B. pseudolongum) to utilize 15 different carbohydrate sources (ei ght oligosaccharide products, and a variety of monosaccharides and dis accharides) 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 oligofru ctose, with a low degree of polymerization, supported best growth of t he test micro-organisms. In contrast, xylooligosaccharides and pyrodex trins 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 constituen ts, particularly with respect to fructooligosaccharides. Bifidobacteri um pseudolongum, B. longum and B. catenulatum were the most nutritiona lly versatile isolates studied in relation to the range of oligosaccha ride products utilized, and the extent to which bacteria could grow on these substrates.