The use of probiotic, postbiotic, and anti-aflatoxigenic capabilities of the lactic acid bacteria (LAB) isolated from stressful niches is a major strategy to prepare functional cultures and bio-preservatives for food industries. In the present study, abundant LAB strains isolated from natural honey were screened based on their tolerance to continuous pH and bile salt treatments. Then, the pro-functional properties of the selected LAB were investigated. In accordance with the screening data, a bacilli isolate was selected for further characterization. Sequencing results led to the identification of Lactobacillus kunkeei as the selected LAB isolate. In vitro antibacterial and antifungal activities of the LAB and in situ antifungal activity of the isolate cell-free supernatant (CFS) were verified against food-borne indicators. Accordingly, in vitro antibacterial and antifungal effects of Lact. kunkeei ENH01 on respective Escherichia coli and Aspergillus niger were significantly (P < 0.05) higher than the other indicators. Furthermore, in situ inhibitory effect of Lact. kunkeei CFS on Candida albicans (as the highest in situ effect) was equal to 76.36%. The presence of three antibacterial peptides was also verified in the Lact. kunkeei CFS according to the results of liquid chromatography mass spectrometry (LC/MS) assay. Antibiotic susceptibility profile and auto-aggregation ability of the isolate were noticeable. Anti-mycotoxigenic capabilities of Lact. kunkeei ENH01 as viable and heat-killed cells were also revealed against total aflatoxins according to the HPLC-based analysis. In vivo safety of the isolate was also attested through the evaluation of blood biochemistry and hematological parameters in the Lact. kunkeei ENH01 fed-mice compared with the control. Based on the findings, probiotic properties of Lact. kunkeei ENH01 and postbiotic capabilities of the isolate CFS and its heat-killed cells were approved.
Keywords: Anti-mycotoxigenic; Honey LAB isolate; In situ antifungal; In vivo safety; Postbiotic.