青春双歧杆菌体外代谢低聚木糖的研究

In vitro fermentation of xylooligosaccharides by Bifidobacterium adolescentis

研究了以酶法制备和以高温降解制备的低聚木糖体外对青春双歧杆菌的增殖作用以及双歧杆菌代谢低聚木糖的规律。结果表明:以酶法制备的3 g/L低聚木糖为碳源时,菌体浓度在18 h达到最大值0.43 g/L,增殖了3.73倍;以高温降解的3 g/L低聚木糖为碳源时,菌体的浓度24 h时达到最大值0.19 g/L,增殖1.16倍。酶法制备低聚木糖增殖效果优于高温降解低聚木糖。在代谢过程中发现青春双歧杆菌优先利用木二、木三糖,在利用聚合度3以上的低聚木糖的同时会释放出阿拉伯糖和木糖。青春双歧杆菌对木二、木三、木四、木五和木六糖利用率分别为94.00%、50.00%、83.87%、60.87%和48.28%,其代谢产物主要是乳酸、乙酸和丙酸。

The proliferation of xylooligosaccharides （XOS） produced from enzyme hydrolysis and high-temperature degradation of xylan to Bifidobacterium adolescentis in vitro was studied. The results showed that in vitro fermentation of B. adolescentis employed 3 g/L enzymatic prepared XOS as carbon sources for 18 h, the highest cell concentration reached 0.43 g/L, and cell proliferation was more than 3.73 times than that of the initial. When B. adolescentis incuba- tion used 3 g/L XOS which prepared from high-temperature degradation of xylan as carbon sources, the maximal cell concentration of 0.19 g/L was obtained for 24 h fermentation and 1.16 times proliferation than that of the initial. It was found that B. adolescentis could metabolize xytobiose and xylotriose preferentially, and released arabinose and xylose while consuming the XOS that DP above 3. It was shown that xylobiose, xylotriose, xyloteraose, xylopentaose, xylohexaose were consumed 94.00 %, 50.00 %, 83.87 %, 60.87 % and 48.28 % of the initial by B. adolescentis. The mainly metabolites of B. adolescentis to XOS were lactate, acetate and propionate.