Effects of Mannan-oligosaccharide on the Growth of Lactobacillus Pure Culture and Co-culture

Abstract:

Effects of mannan-oligosaccharide (MOS) on the growth of Lactobacillus were investigated by pure culture of three swine originated Lactobacillus strains or co-culture with swine pathogenic E. coli. The pure culture results revealed that OD values and lactic acid concentration of three Lactobacillus strains in the MOS supplemented cultures were higher than those of the control group without MOS supplementation, a lower pH was observed for MOS supplement compared with that of the control group. The co-culture results showed that MOS were utilized by both Lactobacillus strains and swine pathogenic E. coli strain. But Lactobacillus grew faster than the latter. A significant increase in lactic acid concentration (P<0.05) and a significant decrease in pH (P<0.05) were observed in the MOS supplemented co-cultures compared with those of the control group or pathogenic E. coli pure culture. Moreover, the changes in numbers of Lactobacillus strains and the pathogenic E. coli strain, the elevation of lactic acid concentration and the reduction of pH were observed to be obvious during the first 12 h fermentation.

Key words:Mannan-oligosaccharide, Lactobacillus, E. coli, pH, Lactic acid concentration