Fermentation of Glucose, Lactose, Galactose, Mannitol, and Xylose by Bifidobacteria

Abstract

For six strains of Bifidobacterium bifidum (Lactobacillus bifidus), fermentation balances of glucose, lactose, galactose, mannitol, and xylose were determined. Products formed were acetate, L(+)-lactate, ethyl alcohol, and formate. L(+)-Lactate dehydrogenase of all strains studied was found to have an absolute requirement for fructose-1 , 6-diphosphate. The phosphoroclastic enzyme could not be demonstrated in cell-free extracts. Cell suspensions fermented pyruvate to equimolar amounts of acetate and formate. Alcohol dehydrogenase was shown in cell-free extracts. Possible explanations have been suggested for the differences in fermentation balances found for different strains and carbon sources. By enzyme determinations, it was shown that bifidobacteria convert mannitol to fructose-6-phosphate by an inducible polyol dehydrogenase and fructokinase. For one strain of B. bifidum, molar growth yields of glucose, lactose, galactose, and mannitol were determined. The mean value of Y (ATP), calculated from molar growth yields and fermentation balances, was 11.3.

Growth of Bifidobacterium longum BB536 in medida (fermented cereal porridge) and their survival during refrigerated storage

“…Theoretically, the bifidus pathway yields 3 mol of acetic acid and 2 mol of lactic acid per 2 mol of glucose in synthetic medium. However, lactic and acetic acids profiles in bifidobacteria‐fermented products vary considerably among different bifidobacteria strains and even within the same species (Vries and Stouthamer 1968). The ratio of acetic to lactic acids produced by B. longum BB 536 in medida was high.…”

Occurrence and Properties of Lactic Dehydrogenases of Fermentative Mycoplasmas

“…This highly specific activation is unusual and at present is known to occur only among the Lactobacillaceae, specifically in streptococci, where this property is common to lactic dehydrogenases of all species which have been examined (43,45,46) and in strains of Lactobacillus bifidus (42). Even though L. bifidus possesses a FDP-activated lactic dehydrogenase, its carbohydrate metabolism differs considerably from that of the streptococci and A. laidlawii (7) in that it lacks key enzymes of the Embden-Meyerhof and hexose monophosphate pathways and catabolizes glucose by the fructose-6-phosphate phosphoketolase route (42). The FDP-activated lactic dehydrogenases of A. laidlawii and the lactic acid bacteria may have molecular similarities, since all must have binding sites for the three ligands, pyruvate, FDP, and NADH.…”

Development of a Chemically Defined Medium for Growth of Bifidobacterium animalis

“…To eventually improve formulation of human-milk substitutes with the goal of promoting dominance by the probiotic intestinal microflora in infants, studies on the effect of native (or deliberately added) nitrogenous constituents are in order. As a consequence of their weak proteolytic activity and requirement for a low redox potential (de Vries and Stouthamer 1968;Rasic and Kurmann 1983), bifidobacterium strains will experience great difficulty in growing in cow's milk if no bifidogenic factors are externally supplied (Klaver and others 1993;Gomes and Malcata 1998). One elegant way to gain information on metabolic behavior takes advantage of fermenter operation, where several physicochemical conditions can be duly controlled; however, among the several studies available that pertain to growth of bifidobacteria in milk, very few encompass use of fermenters as a tool for a better understanding of bacterial activity.…”