INABILITY OF LACTOBACILLUS-PLANTARUM AND OTHER LACTIC-ACID BACTERIA TO GROW ON D-RIBOSE AS SOLE SOURCE OF FERMENTABLE CARBOHYDRATE

Lactobacillus plantarum NCIMB 8026, NCIMB 8026(s), NCIMB 8014, NCFB 17 52, Lact. brevis NCIMB 4617, Leuconostoc mesenteroides NCIMB 8023, Str eptococcus agalactiae NCFB 1348, Pediococcus acidilactici NCFB 1859 an d Ped. pentosaceus NCFB 990 did not grow on D-ribose as the sole sourc e of fermentable carbohydrate in a chemically defined medium but grew on D-ribose in the presence of glucose. Lactobacillus plantarum NCIMB 8026(s) also grew on D-xylose and L-arabinose in the presence but not in the absence of glucose. Enterococcus faecalis NCFB 581 grew with D- ribose as the sole fermentable carbohydrate. Leuconostoc mesenteroides NCIMB 8710 and Lactococcus lactis subsp. lactis NCFB 763 did not use ribose in the presence or absence of glucose. Lactobacillus plantarum NCIMB 8026(s) utilized ribose and glucose simultaneously in the propor tion of approximately 1 ribose to 1 glucose, producing approximately 3 lactate to 1 acetate and similar yields of dry biomass from glucose a nd ribose. Growth of Lact. plantarum 8026(s) with glucose and excess D -ribose ceased when D-glucose was exhausted, but metabolism of D-ribos e to lactic and acetic acids continued. The enzyme system for the meta bolism of D-ribose in Lact. plantarum was inducible, requiring D-gluco se and amino acids for adaptation.