Background: Lactic acid bacteria play a key role in sourdough fermentation. Lactobacilli are the most important group of lactic acid bacteria in sourdough. Therefore, the main objective of this study was to identify Lactobacillus strains in Iranian traditional wheat sourdoughs as a basis for further studies on the technological applications in the production of typical breads.
Methods: Fourteen traditional sourdough samples were collected from the Southern regions in East-Azarbaijan province of Iran. In all sourdough samples, pH and Total Titratable Acidity (TTA) values were determined, and then isolation and identification of Lactobacillus isolates were carried out.
Results: Most sourdough samples had the pH value of 3.64 to 3.90 and the TTA varied from 16.8 to 19.2 ml of 0.1 N NaOH/10 g sourdough. Isolates were divided into two main groups (group A and group B) using phenotypic characteristics, group B subdivided into eight groups. Overall, 38% of the isolates, which clustered together in group A, were closely related to Lactobacillus paralimentarius, while 27% and 20% of the isolates were closely related to Lactobacillus plantarum and Lactobacillus curvatus, respectively. A few isolates were also identified as Lactobacillus agilis and Lactobacillus hilgardii.
Conclusion: Lactobacillus paralimentarius, Lactobacillus plantarum, Lactobacillus curvatus, and the rare presence of Lactobacillus agilis and Lactobacillus hilgardii were identified in Iranian traditional sourdough. These lactobacilli may have potential to be used as starter cultures in the manufacture of sourdough breads with perfect and good quality.