Research Group of Industrial Microbiology and Food Biotechnology, Faculty of Sciences and Bio-engineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
Appl Environ Microbiol. 2011 Jan;77(2):618-26. doi: 10.1128/AEM.02028-10. Epub 2010 Nov 19.
Lactic acid bacteria (LAB) are of industrial importance in the production of fermented foods, including sourdough-derived products. Despite their limited metabolic capacity, LAB contribute considerably to important characteristics of fermented foods, such as extended shelf-life, microbial safety, improved texture, and enhanced organoleptic properties. Triggered by the considerable amount of LAB genomic information that became available during the last decade, transcriptome and, by extension, metatranscriptome studies have become one of the most appropriate research approaches to study whole-ecosystem gene expression in more detail. In this study, microarray analyses were performed using RNA sampled during four 10-day spontaneous sourdough fermentations carried out in the laboratory with an in-house-developed LAB functional gene microarray. For data analysis, a new algorithm was developed to calculate a net expression profile for each of the represented genes, allowing use of the microarray analysis beyond the species level. In addition, metabolite target analyses were performed on the sourdough samples to relate gene expression with metabolite production. The results revealed the activation of different key metabolic pathways, the ability to use carbohydrates other than glucose (e.g., starch and maltose), and the conversion of amino acids as a contribution to redox equilibrium and flavor compound generation in LAB during sourdough fermentation.
乳酸菌（LAB）在发酵食品的生产中具有重要的工业意义，包括酸面团衍生产品。尽管它们的代谢能力有限，但 LAB 对发酵食品的许多重要特性有很大的贡献，如延长保质期、微生物安全性、改善质地和增强感官特性。由于过去十年中获得了大量的 LAB 基因组信息，转录组学，并且通过扩展，元转录组学研究已成为研究整个生态系统基因表达更详细的最合适的研究方法之一。在这项研究中，使用在实验室中用内部开发的 LAB 功能基因微阵列进行的四个为期 10 天的自发酸面团发酵过程中采集的 RNA 进行了微阵列分析。为了进行数据分析，开发了一种新的算法来计算每个代表基因的净表达谱，从而允许在物种水平之外使用微阵列分析。此外，对酸面团样品进行了代谢物靶标分析，以将基因表达与代谢产物的产生联系起来。结果表明，在 LAB 进行酸面团发酵过程中，不同的关键代谢途径被激活，能够利用葡萄糖以外的碳水化合物（例如淀粉和麦芽糖），并将氨基酸转化为对氧化还原平衡和风味化合物生成的贡献。
