Isolation of Enterobacter hohensis 4-2-1 from Human Intestine and Its Fermentation Effect on Lycium Barbarum Polysaccharide

In order to investigate the role of intestinal bacteria in the absorption of Lycium barbarum polysaccharides (LBP), a strain of bacteria was isolated from human intestinal feces, and the strain was applied in the fermentation of LBP. The total number of bacteria, pH, polysaccharide content, reducing sugar content and molecular weight in the fermentation were measured and analysed to initially elucidate the digestion and absorption of LBP. The results showed that the strain was Enterobacter hormaechei through morphological and molecular biology identification, marked 4-2-1, which was a Gram-negative bacterium, and that it reached its maximum total bacterial count at 12 h. After fermentation, the pH of the medium changed from 7.98 to 7.75, the polysaccharide content changed from 682 μg/mL to 205.7 μg/mL, the reducing sugar content changed from 225 μg/mL to 91.32 μg/mL, and the molecular weight changed from 8.02 to 3.44 kDa, the content of LBP decreased to about 30.2%, the content of reducing sugar decreased to about 40.6% and the molecular weight decreased to 42.9%. It indicated that the intestinal bacteria could ferment and utilize LBP, which would provide a basis for further study on the interaction between LBP and intestinal bacteria.