Substrate preference of Bifidobacterium adolescentis MB 239:: compared growth on single and mixed carbohydrates
Substrate preference of Bifidobacterium adolescentis MB 239:: compared growth on single and mixed carbohydrates
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DOI：
10.1007/s00253-006-0500-9
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发表时间：
2006-12-01
影响因子：
5
通讯作者：
Rossi, Maddalena
中科院分区：
文献类型：
--
作者：
Amaretti, Alberto;Tamburini, Elena;Rossi, Maddalena
研究了双歧杆菌MB 239对单糖、双糖和低聚糖的利用.使用棉子糖、低聚果糖（FOS）、乳糖和单体部分葡萄糖和果糖。为了建立一个层次的糖偏好，生长和糖消耗的动力学确定的个人和混合碳水化合物。在单一碳源上，与单糖相比，二糖和寡糖获得了更高的比生长速率和细胞产量。在稳态恒化培养物中，以相同的稀释率在FOS、乳糖或棉子糖上生长，对碳水化合物的分析表明存在单体单元和水解产物。在恒化器培养中，对单个碳水化合物，B。β-半乳糖苷酶MB 239对所有糖（包括单糖）同时显示α-半乳糖苷酶、β-半乳糖苷酶和β-呋喃果糖苷酶活性。糖基水解活性被发现在细胞质，细胞表面，和生长培养基。对碳水化合物混合物的批实验表明，它们被B共代谢。即使登记了不同的消失动力学，也不可能检测到MB 239。当单，二，和低聚糖同时存在于培养基中，没有优先单糖利用观察到，和二和低聚糖消耗之前，其组成部分。
The utilization of mono-, di-, and oligosaccharides by Bifidobacterium adolescentis MB 239 was investigated. Raffinose, fructooligosaccharides (FOS), lactose, and the monomeric moieties glucose and fructose were used. To establish a hierarchy of sugars preference, the kinetics of growth and sugar consumption were determined on individual and mixed carbohydrates. On single carbon sources, higher specific growth rates and cell yields were attained on di- and oligosaccharides compared to monosaccharides. Analysis of the carbohydrates in steady-state chemostat cultures, growing at the same dilution rate on FOS, lactose, or raffinose, showed that monomeric units and hydrolysis products were present. In chemostat cultures on individual carbohydrates, B. adolescentis MB 239 simultaneously displayed alpha-galactosidase, beta-galactosidase, and beta-fructofuranosidase activities on all the sugars, including monosaccharides. Glycosyl hydrolytic activities were found in cytosol, cell surface, and growth medium. Batch experiments on mixtures of carbohydrates showed that they were co-metabolized by B. adolescentis MB 239, even if different disappearance kinetics were registered. When mono-, di-, and oligosaccharides were simultaneously present in the medium, no precedence for monosaccharides utilization was observed, and di- and oligosaccharides were consumed before their constitutive moieties.