Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan; Central Laboratory of Yamazaki Baking Company Limited, 3-23-27 Ichikawa, Ichikawa-shi, Chiba 272-8581, Japan.
Laboratory of Microbial Technology, Division of Systems Bioengineering, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
J Biosci Bioeng. 2019 Aug;128(2):170-176. doi: 10.1016/j.jbiosc.2019.02.006. Epub 2019 Mar 14.
Wheat sourdough is a common traditional fermented food that is produced worldwide. However, product quality of spontaneous sourdough is not easy to control because it depends on natural fermentation and backslopping, about which little is known, notably after ten backslopping steps. To this end, we tracked the spontaneous fermentation of three sourdoughs made from wheat flours during 32 backslopping steps for 60 days. At 24 time points, the microbial community was analyzed by both culture-dependent and culture-independent methods and its chemical constituents were assessed. Dynamic changes were observed in the microbial community, which showed a common succession pattern among the three sourdoughs at the bacterial family level and differences at the species level. The bacterial communities evolved through three phases that were driven by different groups of lactic acid bacteria (LAB) species. The dynamism among the metabolites also differed, depending on the species composition of the LAB and yeast communities. In one sourdough, the growth of Saccharomyces cerevisiae was detected along with a concentration of increased ethanol, while in the other two sourdoughs, Wickerhamomyces anomalus was detected without ethanol production. Regarding the LAB communities, two sourdoughs were eventually co-dominated by Lactobacillus plantarum and L. brevis, while the other sourdough was eventually dominated solely by the heterolactic fermentative bacterium Lactobacillus fermentum, and ethanol was produced at the same level as lactic acid. Further research is needed to determine the bacterial and yeast species involved in the fermentation of sourdough, to help improve the design and quality control of the final product.
小麦酸面团是一种常见的传统发酵食品，在世界各地都有生产。然而，自发酸面团的产品质量不容易控制，因为它依赖于自然发酵和回种，关于这一点知之甚少，尤其是经过十次回种步骤之后。为此，我们跟踪了三种由小麦粉制成的酸面团在 32 次回种步骤中的自发发酵过程，历时 60 天。在 24 个时间点，通过培养依赖和培养独立的方法分析了微生物群落，并评估了其化学成分。观察到微生物群落发生了动态变化，在细菌科水平上，三种酸面团显示出共同的演替模式，而在种水平上则存在差异。细菌群落通过三个阶段演变，这三个阶段由不同组的乳酸菌（LAB）物种驱动。代谢物之间的动态变化也不同，这取决于 LAB 和酵母群落的物种组成。在一种酸面团中，检测到酿酒酵母的生长以及乙醇浓度的增加，而在另外两种酸面团中，检测到异常威克汉姆酵母而没有乙醇产生。关于 LAB 群落，两种酸面团最终由植物乳杆菌和短乳杆菌共同主导，而另一种酸面团最终仅由异型发酵细菌发酵乳杆菌主导，并且产生与乳酸相同水平的乙醇。需要进一步研究确定参与酸面团发酵的细菌和酵母物种，以帮助改善最终产品的设计和质量控制。
