Genome Structure of the Symbiont Bifidobacterium pseudocatenulatum CECT 7765 and Gene Expression Profiling in Response to Lactulose-Derived Oligosaccharides.
Genome Structure of the Symbiont Bifidobacterium pseudocatenulatum CECT 7765 and Gene Expression Profiling in Response to Lactulose-Derived Oligosaccharides.
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DOI：
10.3389/fmicb.2016.00624
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发表时间：
2016
影响因子：
5.2
通讯作者：
Sanz Y
中科院分区：
文献类型：
--
作者：
Benítez-Páez A;Moreno FJ;Sanz ML;Sanz Y
从母乳喂养婴儿的粪便中分离出假小链双歧杆菌CECT 7765。尽管该菌株通常被认为是成人型双歧杆菌菌种，但也已显示其在肥胖模型中具有临床前功效。为了了解其适应复杂碳水化合物的分子基础并提高其潜在的功能性，我们分析了其基因组和转录组，以及其在乳果糖衍生的低聚半乳糖（GOS-Lu）中生长时的代谢产物作为碳源。B。pseudocatenulatum CECT 7765显示了菌株特异性基因组区域，包括糖代谢相关基因的巨大多样性。初步和探索性的转录组分析表明，候选过表达的几个基因编码的糖转运蛋白和permease;此外，五个在基因组中确定的七个β-半乳糖苷酶可以激活响应GOS-Lu曝光。在这里，我们还提出，一个特定的基因簇参与控制进口和水解的某些二-和三-的，这似乎是那些主要采取了由biobacterium菌株。这是从培养物上清液的不同糖级分的基于质谱的定量中辨别出来的。我们的研究结果证实，参与糖的运输和代谢，并在合成亮氨酸，一种氨基酸，在葡萄糖和能量稳态的关键作用，基因的表达被上调GOS-Lu。除了从单复制RNAseq方法获得的探索性信息外，还使用qPCR以及预测在B中编码的基因的功能注释来完成。假小链藻CETC 7765基因组。
Bifidobacterium pseudocatenulatum CECT 7765 was isolated from stools of a breast-fed infant. Although, this strain is generally considered an adult-type bifidobacterial species, it has also been shown to have pre-clinical efficacy in obesity models. In order to understand the molecular basis of its adaptation to complex carbohydrates and improve its potential functionality, we have analyzed its genome and transcriptome, as well as its metabolic output when growing in galacto-oligosaccharides derived from lactulose (GOS-Lu) as carbon source. B. pseudocatenulatum CECT 7765 shows strain-specific genome regions, including a great diversity of sugar metabolic-related genes. A preliminary and exploratory transcriptome analysis suggests candidate over-expression of several genes coding for sugar transporters and permeases; furthermore, five out of seven beta-galactosidases identified in the genome could be activated in response to GOS-Lu exposure. Here, we also propose that a specific gene cluster is involved in controlling the import and hydrolysis of certain di- and tri-saccharides, which seemed to be those primarily taken-up by the bifidobacterial strain. This was discerned from mass spectrometry-based quantification of different saccharide fractions of culture supernatants. Our results confirm that the expression of genes involved in sugar transport and metabolism and in the synthesis of leucine, an amino acid with a key role in glucose and energy homeostasis, was up-regulated by GOS-Lu. This was done using qPCR in addition to the exploratory information derived from the single-replicated RNAseq approach, together with the functional annotation of genes predicted to be encoded in the B. pseudocatenulatum CETC 7765 genome.