The antifungal effect of di-acetyl produced by the isolated lactobacilli from traditional dairy products

Filamentous fungi or molds are the major group of spoilage microorganisms responsible for significant economic losses and serious health risks in the food chain. This study was conducted to evaluate the antifungal effect of di-acetyl produced by Lactobacillus species isolated from traditional fermented product against Penicillium sp. Thirty-three samples of traditional yoghurt, dough, and kefir were cultured, then the isolates were identified by molecular methods (specific PCR and ۱۶S rRNA sequence analysis) and biochemical test. The effects of different media were analyzed in biomass and di-acetyl production. Antifungal activity of di-acetyl was assessed against Penicillium sp. Out of ۱۶ isolates from kefir, yoghurt, and dough, ۱۰ lactic acid bacteria (LAB) isolates were identified as L. casei by biochemical test and molecular methods. MR-VP medium has exhibited the best effect on biomass and di-acetyl production by isolates. GC analysis showed that yoghurt- LABs producing of high di-acetyl have a considerable inhibitory effect on Penicillium sp. The antifungal properties of di-acetyl generated by novel L. casei isolates seem to present a promising advantage, indicating the potential of di-acetyl as a bio-preservative in the food and dairy industries. It may recommended to apply the di-acetyl in fermented product-surface papers to prevent mildew cause by Penicillium sp.

کلیدواژه ها:

Antifungal activity ، Di-acetyl ، Lactobacillus casei ، Penicillium sp ، Dairy product