Isolation of Lactobacillus strain from curdled milk and investigation of their antimycotoxinogen activity

Lactic bacteria are used in fermentation and food bio‐preservation through their production of organic acids and other antimicrobial substances like bacteriocins which restrain certain fungal strains. The main objective of this study is the isolation of Lactobacillus strains from curdled milk samples, in order, to inhibit, in vitro, mycotoxins production by Aspergilus flavus. Six bacterial isolates were obtained from curdled milk commercialized in the region of Constantine. Among them, one isolate coded (B6) had a significant inhibitory effect against A. flavus (the diameter of colony not exceeding 1.5 cm after 72 hr of incubation at 28°C). This isolate (B6), was identified morphologically and biochemically. The obtained results showed that this bacterial isolate belongs Lactobacillus genus. In addition, its antimycotoxinogen activity had been confirmed using some test bacteria, such as E. coli, Staphylococcus aureus, Klebsiella sp., and Pseudomenas syringae. PRACTICAL APPLICATIONS: This paper describes the isolation of lactic bacteria strains from Algerian curdled milk and the study of their antifungal and antimycotoxinogen activity. The method used to test the effect of lactic bacteria strains against toxigenic fungi was not previously exploited. The main objectives were to: (a) Isolate and select the lactic bacteria from curdled milk; (b) Isolate and identify the toxigenic fungi; (c) Select bacterial isolates for antifungal effect against toxigenic fungi; (d) Study of their antimycotoxinogen activity, in vitro.