Synbiosis between Enterococcus faecium DSM 3530 and Fructan Compounds of Different Degree of Polymeriza tion: a Preliminary In vitro Assay in a Condition Simulated Chicken Caecum

Abstract

This experiment was conducted to determine the pote ntial synergistic relationship between Enterococcus faecium and fructans with different average Degree of Polymerization (DPav) including OligoFructose (OF, DPav 4), Standard-inulin (ST-inulin, DPav 10), Synergy1-Inulin (SYN1-inulin, DPav 15) an d High-Polymer inulin (HP-inulin, DPav 25). A sterilized minimal MRS broth media was prepared by omission of glucose. The media pH was adjusted to a constant initial val ue of 5.8±0.1 and the temperature was maintained at 41°C. Sterilized fructans were added ( 1% wt ⁄vol) to the broths, as experimental treatments with 3 replications each, a nd the medium with no added prebiotic was considered as the control. The same s tarting density of 10 8 E. faecium cells per ml was introduced to all media. The media pH, v iable cells count, as well as growth of the latter were determined during 24 hours of incubation. The lowest pH and best growth rates were observed in the media enriched with OF a nd ST-inulin. Unlike aerobic, the anaerobic conditions produced no significant differ ences in growth of the bacteria among SYN1-inulin and HP-inulin treatments compared to th e control. The viable cells count in the media containing OF was significantly higher th an in the control and other treatments. The significant differences were also f ound among the control and treatments supplemented with ST-inulin and SYN1-inulin. In con clusion, the fructans with lower DP were preferentially metabolized by E. faecium , and hence it follows that a synbiotic blend of E. faecium and OF has the potential to be used in poultry nutr ition. Keywords : Degree of polymerization, Enterococcus faecium , In vitro , Inulin-type fructans, Synbiotic.