Screening of Lactic Acid Bacteria Isolated from Iranian sourdoughs for Antifungal Activity: Enterococcus faecium showed the Most Potent Antifungal Activity in Bread

摘要

Background and Objective: The use of antifungal lactic acid bacteria as starter for bread making could be a good alternative to improve the stability of bread shelf life. Material and Methods: In this study, a total of 57 lactic acid bacteria were isolated from spontaneously fermented wheat sourdoughs collected in Chahar-Mahalo Bakhryari province of Iran. The isolates were screened for in vitro antifungal activity (towards Aspergilus niger or Penicillium roqueforti ); and the selected isolates (six isolates) were applied in flat bread making. The freshly baked breads were nebulized with a suspension of either molds, containing 104 spores ml-1, and the fungal growth on breads was monitored over a 7-day storage period. Results and Conclusion: Bread produced with either isolates AN3 and MB1 (both were identified as Enterococcus faecium ) restrained the growth of Aspergillus niger for up to 5 days. Even though none of the isolates were strong enough to inhibit the growth of Penicillium roquforti on bread, the surface area of breads contaminated by this fungus was significantly lower than the control samples. To our knowledge, it was the first report indicating the anti-mold activity of Enterococcus faecium strains isolated from sourdough. These isolates seem to be promising for further analysis and their application in bread industry for prolonging the shelf life. Conflict of interest: The authors declare that there is no conflict of interest.