Microbial dynamics of sourdough ferment produced with six different wheat flours

Abstract Bacteria, especially lactic acid bacteria (LAB), and yeasts are responsible for sourdough fermentation. Flour acts as a source of microorganisms, crucial for establishing the microbiota. There are no studies investigating how different Brazilian wheat flours modulate sourdough microbiota. This study explores the microbial and physico-biochemical dynamics of sourdoughs from six distinct Brazilian wheat flours, with aim to investigate whether the variations in raw materials influence the microbial consortia in sourdough. Physical-chemical and microbiological analyses were performed; microbial population dynamics were assessed by culture-dependent methods, while community composition was characterized using culture-independent (amplicon-based) sequencing. Sequencing results showed LAB composing the microbiota of the flours, especially sequences affiliated with Lactiplantibacillus plantarum , Latilactobacillus sakei and Pediococcus spp. Differences in bacterial consortium were observed according to flour types and agricultural system. In relation to the yeast, none were identified in the flour, potentially explaining the limited yeast biodiversity. Non-typical yeasts were predominant in some mature sourdoughs. Meyerozyma guilliermondi , Rhodotorula mucilaginosa , and Wickerhamomyces anomalus were identified as dominant only in sourdoughs prepared with white flour, whereas Candida glabrata was present in those made with whole wheat flour. The differences demonstrated in sourdough microbial diversity were related to the raw material microbiota. Therefore, it can play an important role in microbiota, and consequently, in sourdough fermentation.