Department of Genetics, Biology of Microorganisms, Anthropology and Evolution, University of Parma, Parma, Italy.
J Appl Microbiol. 2011 Oct;111(4):855-64. doi: 10.1111/j.1365-2672.2011.05101.x. Epub 2011 Aug 8.
Lactobacillus rhamnosus is a dominant species during Parmigiano Reggiano cheese ripening and exhibits a great adaptability to unfavourable growth conditions. Gene expression of a Lact. rhamnosus, isolated from Parmigiano Reggiano cheese, grown in a rich medium (MRS) and in a cheese-like medium (CB) has been compared by a novel cDNA-amplified fragment length polymorphism (cDNA-AFLP) protocol.
Two techniques, capillary and gel electrophoresis cDNA-AFLP, were applied to generate unique transcript tags from reverse-transcribed messenger RNA using the immobilization of biotinylated 3'-terminal cDNA fragments on streptavidin-coated Dynabeads. The use of three pairs of primers allowed detecting 64 genes expressed in MRS and 96 in CB. Different transcripts were observed when Lact. rhamnosus was cultured on CB and MRS.
The cDNA-AFLP approach proved to be able to show that Lact. rhamnosus modifies the expression of a large part of genes when cultivated in CB compared with growth under optimal conditions (MRS). In particular, the profiles of the strain grown in CB were more complex probably because the cells activate different metabolic pathways to generate energy and to respond to the environmental changes.
This is the first research on Lact. rhamnosus isolated from cheese and represents one of the few concerning bacterial transcriptomic analysis towards cDNA-AFLP approaches.
鼠李糖乳杆菌是帕尔马干酪成熟过程中的优势种，对不利的生长条件具有很强的适应性。本研究通过新型 cDNA 扩增片段长度多态性（cDNA-AFLP）方案比较了从帕尔马干酪中分离的鼠李糖乳杆菌在丰富培养基（MRS）和干酪样培养基（CB）中的基因表达。
使用固定在链霉亲和素包被的 Dynabeads 上的生物素化 3'-末端 cDNA 片段，两种技术，毛细管电泳和凝胶电泳 cDNA-AFLP，用于从反转录的信使 RNA 生成独特的转录标签。使用三对引物可检测到在 MRS 中表达的 64 个基因和在 CB 中表达的 96 个基因。当鼠李糖乳杆菌在 CB 和 MRS 上培养时，观察到不同的转录物。
cDNA-AFLP 方法证明，与在最佳条件（MRS）下培养相比，当在 CB 中培养时，鼠李糖乳杆菌会改变大部分基因的表达。特别是，在 CB 中生长的菌株的图谱可能更复杂，因为细胞激活不同的代谢途径来产生能量并对环境变化做出反应。
这是首次对从奶酪中分离的鼠李糖乳杆菌进行的研究，也是少数涉及细菌转录组分析的 cDNA-AFLP 方法之一。
