Summary: | Preventing food spoilage without the addition of chemical food additives, while increasing functional properties of wheat-based bakery products, is an increasing demand by the consumers and a challenge for the food industry. Within this study, lactic acid bacteria (LAB) isolated from sourdough were screened in vitro for the ability to utilize the typical wheat carbohydrates, for their antimicrobial and functional properties. The dual culture overlay assay revealed varying levels of inhibition against the examined fungi, with <i>Lactiplantibacillus plantarum</i> S4.2 and <i>Lentilactobacillus</i><i>parabuchneri</i> S2.9 exhibiting the highest suppression against the indicator strains <i>Fusarium graminearum</i> MUCL43764, <i>Aspergillus fumigatus</i>, <i>A. flavus</i> MUCL11945, <i>A. brasiliensis</i> DSM1988, and <i>Penicillium roqueforti</i> DSM1079. Furthermore, the antifungal activity was shown to be attributed mainly to the activity of acids produced by LAB. The antibacillus activity was evaluated by the spot-on-the-lawn method revealing a high inhibition potential of the majority of LAB isolated from sourdough against <i>Bacillus cereus</i> DSM31, <i>B. licheniformis</i> DSM13, <i>B. subtilis</i> LMG7135, and <i>B. subtilis</i> S15.20. Furthermore, evaluating the presence of the glutamate decarboxylase gen in LAB isolates by means of PCR showed a strain dependency of a potential GABA production. Finally, due to improved functional activities, LAB isolated from sourdoughs exhibit promising characteristics for the application as natural preservatives in wheat-based bakery products.
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