Study On The Proliferative Effects Of Lotus-seed Oligosaccharides On Bifidobacterium Adolescence

Lotus-Seed (Nelumbo nucifera Gaertn.) is one of the special economical resourcein Fujian Province, which contains rich nutrition and special health value. In thispaper, oligosaccharides were extracted as the material from lotus-seed, theproliferative effects of Bifidobacterium in vitro, the effects of Bifidobacteriumadolescence with acquired tolerance to simulated human gastrointestinal tract, theRSM was used to optimize Bifidobacterium medium components, the separatedtechnology and the structure information were studied. The application of oligo-saccharides is expanded, the basis data were offered for the lotus-seed's functionresearch.The proliferative effects of lotus-seed oligosaccharides on Bifidobacterium ado-lescentis in vitro were studied. The results showed that: the proliferative effects ofLSO was considerable significant difference with GLU, XOS and FOS (P<0.01). Thebest concentration of LSO in medium was7g/L. The retardate time of Bifidobacter-ium adolescence in LSO medium was shorter than GLU medium, which can be shownthat LSO was an effective Bifidobacterium factor proliferation.The simulated gastric tolerance of Bifidobacterium adolescence with LSO wasassayed and compared with GLU, XOS and FOS. The results showed that: Bifido-bacterium adolescence was incubated at pH2.0for1.5h or pH2.0and pH3.0for3h,the acid tolerance of Bifidobacterium adolescence can be improved signifycantly byLSO in this environment (P<0.05). The bile tolerance of Bifidobacterium adolescencecan be improved significantly by LSO in the1%bovine bile salt and compared withXOS and FOS (P<0.05). The simulated gastric juices tolerance of Bifidobacteriumadolescence with LSO was not significant difference with the others by in thesimulated digestive juice (P>0.05). The results indicated that the ability ofBifidobacterium adolescence in simulated human gastrointestinal tract can beenhanced by LSO, suggesting that the resistance to digestion of LSO may beperformed.Fractional factorial and central composite experimental design combined with response surface methodology was used to optimize the composition of Bifido-bacterium adolescence medium, the results show that: the important factors of theBifidobacterium medium which made influence for the dry weight of Bifidobacteriumadolescence was lotus-seed oligosaccharides, tryptone, and pH. The optimum mediumcompositions were as follows: soybean peptone5g/L, LSO7.91g/L, tryptone3.66g/L,yeast extract10g/L, and Twain-801mL, of L-cysteine hydrochloride0.5g/L, inorga-nic salt solution40mL, pH7.04,Final dry weight of biomass was4.722g/L. Theregression model of the dried cells weight was listed as follows:Y=19.327x₁+15.896x₂+17.720x₃-1.008x₁x₁-0.515x₁x₂-0.212x₁x₃-2.103x₂x₂+0.509x₂x₃-1.271x₃x₃-163.217The LSO was extracted in hot water and it was isolated by DEAE-52, SephadexG-15and Sephadex G-25, which contained three components: LSO1, LSO2, andLSO3-2. The results of UV band scanning analysis showed that the protein had beenbasically removed from the LSO dissolvent after being purified. High performanceliquid chromatography analysis showed that the sugar chain of LSO was consist ofD-fructose. The analysis of infrared spectra fingerprint characteristic absorption peakshowed that the three components of LSO contain carboxyl, LSO1and LSO2monosaccharide residues was bonded by the α-glycosidic and consited by pyran ringform.