In Vitro Kinetic Analysis of Oligofructose Consumption by Bacteroides and Bifidobacterium spp. Indicates Different Degradation Mechanisms

Abstract

The growth of pure cultures of Bacteroides thetaiotaomicron LMG 11262 and Bacteroides fragilis LMG 10263 on fructose and oligofructose was examined and compared to that of Bifidobacterium longum BB536 through in vitro laboratory fermentations. Gas chromatography (GC) analysis was used to determine the different fractions of oligofructose and their degradation during the fermentation process. Both B. thetaiotaomicron LMG 11262 and B. fragilis LMG 10263 were able to grow on oligofructose as fast as on fructose, succinic acid being the major metabolite produced by both strains. B. longum BB536 grew slower on oligofructose than on fructose. Acetic acid and lactic acid were the main metabolites produced when fructose was used as the sole energy source. Increased amounts of formic acid and ethanol were produced when oligofructose was used as an energy source at the cost of lactic acid. Detailed kinetic analysis revealed a preferential metabolism of the short oligofructose fractions (e.g., F 2 and F 3 ) for B. longum BB536. After depletion of the short fractions, the larger oligofructose fractions (e.g., F 4 , GF 4 , F 5 , GF 5 , and F 6 ) were metabolized, too. Both Bacteroides strains did not display such a preferential metabolism and degraded all oligofructose fractions simultaneously, transiently increasing the fructose concentration in the medium. This suggests a different mechanism for oligofructose breakdown between the strain of Bifidobacterium and both strains of Bacteroides, which helps to explain the bifidogenic nature of inulin-type fructans.

Diversity of autochthonous bacterial communities in the intestinal mucosa of grass carp (Ctenopharyngodon idellus) (Valenciennes) determined by culture-dependent and culture-independent techniques

“…Although Bacteroidetes, Deinococcus-Thermus and Verrucomicrobia only made up a small proportion of bacterial sequences retrieved from the host intestines, they might play an important role in host nutrition metabolism. Bacteroidetes have been found in the intestinal microbiota of various organisms (Flint, Bayer, Rincon, Lamed & White 2008) and participate in fermentative metabolism and degradation of oligosaccharides derived from plant material (Van der Meulen, Makras, Verbrugghe, Adriany & De Vuyst 2006). DeinococcusThermus species are known for their resistance to extreme stresses, such as radiation, oxidation, desiccation and high temperature (Tian & Hua 2010), but their functional role in the gut of C. idellus deserves further research.…”

Kinetic Analysis of Bifidobacterial Metabolism Reveals a Minor Role for Succinic Acid in the Regeneration of NAD + through Its Growth-Associated Production

“…This limits the production of lactic acid, which results in an increase in the theoretical ratio of acetic acid to lactic acid. Moreover, degradation of inulin-type fructans increases acetic acid production at the cost of lactic acid (39,40). Detailed knowledge about the metabolism of bifidobacteria is very important because of the widespread use of these microorganisms as probiotics or as target organisms for prebiotic substrates.…”

“…Of all the candidate prebiotics tested to date, inulin-type fructans are the most promising, and consequently, the consumption of fructans by bifidobacteria has been studied in detail both in vitro and in vivo (13,15,24,31,33,(39)(40)(41).…”

Bacteroides faecis sp. nov., isolated from human faeces

“…Some species of the genus Bacteroides, including Bacteroides thetaiotaomicron, are known to be decomposers in the colon by fermenting carbohydrates and catabolizing polysaccharides (hemicellulose and xylan) (Falony et al, 2009;Flint, 2006;Salyers, 1995;Van der Meulen et al, 2006). Novel strains of members of the genus Bacteroides from human faeces and intestinal organs have been identified using cultureindependent techniques based on 16S rRNA gene sequence analysis (Dore et al, 1998; Eckburg et al, 2005; Gill et al, 2006;Hayashi et al, 2003;Li et al, 2009;Palmer et al, 2007) and several novel species have recently been identified and characterized (Bakir et al, 2006a, b, c;Chassard et al, 2008; Hayashi et al, 2007;Kitahara et al, 2005;Robert et al, 2007;Song et al, 2004).…”