Urien Charlotte, Legrand Judith, Montalent Pierre, Casaregola Serge, Sicard Delphine
GQE-Le Moulon, INRA, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, Gif-sur-Yvette, France.
Micalis Institute, INRA, AgroParisTech, CIRM-Levures, Université Paris-Saclay, Jouy-en-Josas, France.
Front Microbiol. 2019 Feb 18;10:201. doi: 10.3389/fmicb.2019.00201. eCollection 2019.
Microbial communities are essential for the maintenance and functioning of ecosystems, including fermented food ecosystems. The analysis of food microbial communities is mainly focused on lactic acid bacteria (LAB), while yeast diversity is less understood. Here, we describe the fungal diversity of a typical food fermented product, sourdough bread. The species diversity of 14 sourdoughs collected from bakeries located all over France was analyzed. Bakeries were chosen to represent diverse bakery practices and included bakers and farmer-bakers. Both non-culture-based (pyrosequencing of Internal Transcribed Spacer 1 amplicons) and culture-based methods were used. While both identification methods were in agreement regarding the dominant yeast species of each sourdough, the ITS1 metabarcoding analysis identified an increased number of fungal species in sourdough communities. Two third of the identified sequences obtained from sourdoughs were , mostly in the genus. No species was shared by all the sourdoughs, whereas five other fungal species, mainly known plant pathogens, were found in all sourdoughs. Interestingly, , known as "baker's yeast," was identified as the dominant species in only one sourdough. By contrast, five species were identified as the dominant sourdough species, including one recently described species, and an undescribed sp. Sourdoughs from farmer-bakers harbored and two newly described species, while sourdough from bakers mostly carried as the dominant species. Such yeast diversity has not been found in sourdoughs before, highlighting the need to maintain different traditional food practices to conserve microbial diversity.
微生物群落对于包括发酵食品生态系统在内的生态系统的维持和功能至关重要。食品微生物群落的分析主要集中在乳酸菌（LAB）上，而酵母多样性的了解较少。在这里，我们描述了一种典型的发酵食品——酸面团面包的真菌多样性。分析了从法国各地面包店收集的14种酸面团的物种多样性。选择这些面包店是为了代表不同的面包制作方式，包括面包师和农民面包师。同时使用了基于非培养的方法（内转录间隔区1扩增子的焦磷酸测序）和基于培养的方法。虽然两种鉴定方法在每种酸面团的优势酵母种类上是一致的，但ITS1元条形码分析确定了酸面团群落中真菌种类的增加。从酸面团中获得的已鉴定序列中有三分之二是 ，主要属于 属。并非所有酸面团都共享 物种，而在所有酸面团中都发现了其他五种真菌，主要是已知的植物病原体。有趣的是，被称为“面包酵母”的 仅在一种酸面团中被鉴定为优势物种。相比之下，有五种 物种被鉴定为酸面团优势物种，包括最近描述的一种 物种、 和一种未描述的 种。农民面包师制作的酸面团含有 和两种新描述的 物种，而面包师制作的酸面团大多以 作为优势物种。以前在酸面团中尚未发现这种酵母多样性，这突出表明需要保持不同的传统食品制作方式以保护微生物多样性。
