Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
Department of Carbohydrate Technology, Faculty of Food Technology, University of Agriculture in Krakow, Krakow, Poland.
Microbiologyopen. 2020 Apr;9(4):e1009. doi: 10.1002/mbo3.1009. Epub 2020 Feb 11.
Sourdough fermentation is a traditional process that is used to improve bread quality. A spontaneous sourdough ecosystem consists of a mixture of flour and water that is fermented by endogenous lactic acid bacteria (LAB) and yeasts. The aim of this study was to identify bacterial diversity during backslopping of spontaneous sourdoughs prepared from wheat, spelt, or rye wholemeal flour. Culture-dependent analyses showed that the number of LAB (10 CFU/ml) was higher by three orders of magnitude than the number of yeasts (10 CFU/ml), irrespective of the flour type. These results were complemented by next-generation sequencing of the 16S rDNA V3 and V4 variable regions. The dominant phylum in all sourdough samples was Firmicutes, which was represented exclusively by the Lactobacillales order. The two remaining and less abundant phyla were Proteobacteria and Bacteroidetes. The culture-independent approach allowed us to detect changes in microbial ecology during the 72-hr fermentation period. Weissella sp. was the most abundant genus after 24 hr of fermentation of the rye sourdough, but as the process progressed, its abundance decreased in favor of the Lactobacillus genus similarly as in wheat and spelt sourdoughs. The Lactobacillus genus was dominant in all sourdoughs after 72 hr, which was consistent with our results obtained using culture-dependent analyses. This work was carried out to determine the microbial biodiversity of sourdoughs that are made from wheat, spelt, and rye wholemeal flour and can be used as a source of strains for specific starter cultures to produce functional bread.
酸面团发酵是一种传统工艺，用于改善面包质量。自发酸面团生态系统由面粉和水的混合物组成，由内源性乳酸菌 (LAB) 和酵母发酵而成。本研究的目的是鉴定从小麦、斯佩耳特小麦或黑麦全麦面粉制备的自发酸面团backslopping 过程中的细菌多样性。依赖培养的分析表明，LAB 的数量（10 CFU/ml）比酵母的数量（10 CFU/ml）高三个数量级，与面粉类型无关。这些结果通过 16S rDNA V3 和 V4 可变区的下一代测序得到补充。所有酸面团样品中的优势门是厚壁菌门，仅由乳杆菌目代表。其余两个数量较少的门是变形菌门和拟杆菌门。非培养方法允许我们检测到 72 小时发酵过程中微生物生态的变化。魏斯氏菌属是黑麦酸面团发酵 24 小时后最丰富的属，但随着发酵过程的进行，其丰度下降，有利于乳杆菌属，这与小麦和斯佩耳特小麦酸面团相似。在 72 小时后，乳杆菌属在所有酸面团中占主导地位，这与我们使用依赖培养的分析获得的结果一致。这项工作旨在确定从小麦、斯佩耳特小麦和黑麦全麦面粉制成的酸面团的微生物多样性，可作为生产功能性面包的特定发酵剂菌株的来源。
