Sourdough is used in production of (steamed) bread as leavening agent (type I sourdoughs) or as baking improver to enhance flavour, texture, and shelf life of bread (type II sourdoughs). The long-term propagation of sourdoughs eliminates dispersal limitation and consistently leads to sourdough microbiota that are composed of host adapted lactobacilli. In contrast, community assembly in spontaneous cereal fermentations is limited by dispersal and nomadic or environmental lactic acid bacteria are the first colonizers of these sourdoughs.

Propagation of sourdoughs for use as sole leavening agent (type I sourdoughs) dictates fermentation conditions that select for rapid growth. Type I wheat- and rye sourdoughs are consistently populated by insect-adapted lactobacilli, particularly Lactobacillus sanfranciscensis, which is characterized by a small genome size and a restricted metabolic potential. The diverse fermentation conditions employed in industrial or artisanal Type II sourdough fermentation processes also result in a more diverse microbiota. Nevertheless, type II sourdoughs are typically populated by vertebrate host adapted lactobacilli of the L. delbrueckii and L. reuteri groups. Metabolic traits of host-adapted lactobacilli that enhance competitiveness in intestinal ecosystems also provide technological functionality in bread making. Examples include formation of exopolysaccharides, arginine-, glutamine- and glutamate based mechanisms of acid resistance, and glycosyl hydrolases that reduce FODMAP levels in sourdough and sourdough bread. In conclusion, consideration of the lifestyle of sourdough lactobacilli facilitates the selection of competitive and functional sourdough starter cultures.

酸面团用于生产（蒸制的）面包，作为膨松剂（I型面团）或烘烤改良剂，以增强面包的风味，质地和保质期（II型面团）。酵母的长期繁殖消除了扩散限制，并始终导致由宿主适应性乳杆菌组成的酵母菌群。相反，自然谷物发酵中的群落组装受到分散的限制，游牧或环境乳酸菌是这些酵母的第一批定植者。

用作唯一膨松剂的酵母的繁殖（I型酵母）决定了选择快速生长的发酵条件。I型小麦和黑麦酵母始终由昆虫适应性乳杆菌，尤其是乳酸杆菌（Lactobacillus sanfranciscensis）组成，其特征是基因组规模小且代谢潜力有限。在工业或手工II型酸面团发酵过程中采用的多种发酵条件也导致了更多样化的微生物群。然而，II型酵母菌通常是由脊椎动物宿主适应的德氏乳杆菌和罗伊氏乳杆菌组成的。组。宿主适应性乳酸菌的代谢特性增强了肠道生态系统的竞争力，也为面包生产提供了技术功能。实例包括胞外多糖的形成，基于精氨酸，谷氨酰胺和谷氨酸的耐酸性机制，以及降低面团和面团中FODMAP含量的糖基水解酶。总之，考虑发酵酵母的生活方式有助于选择具有竞争性和功能性的酵母发酵剂文化。