Evaluation of Limosilactobacillus fermentum MYSAGAM1 isolated from herbal Amla juice as a probiotic candidate with antifungal characteristics against Fusarium equiseti

Abstract

Mycotoxigenic fungi and their mycotoxins epitomize broad food spoilage and food safety problems worldwide. Fusarium contamination of foods and feeds has raised a concern associated with severe health issues causing economic burden. Fusarium equiseti species stand out among the group with lethal toxicity which can contaminate the cereal crops via trichothecenes production. A well-known food fermenting Lactic acid bacterium (LAB) has gained attention over the years for its anti-fungal and anti-mycotoxigenic capabilities. In the current study, 20 LABs isolated from traditional herbal Amla juice were screened to determine the inhibition of the Fusarium equiseti. Among them, Limosilactobacillus fermentum MYSAGAM1 showed potent anti-fungal activity by exhibiting the morphological modifications of damaged mycelia and deformed conidia in Fusarium equiseti. The cell-free supernatant (CFS) from L. fermentum reduced mycelial biomass to 0.135 g compared to 2.464 g in control. The conidial germination was inhibited at 23.22% by using 20% CFS. The fungal growth inhibition was also observed in maize kernels over the control after the specified 7 days of incubation with CFS of MYSAGAM1. The inhibitory efficacy was displayed due to the presence of organic acids, which were analyzed through CFS characterization via LC-MS. Additionally, the strain MYSAGAM1 showed promising probiotic properties by tolerating acidic pH-2, exhibiting a survival rate of 73.50% at 2 h, 34.18% at 4 h, bile tolerance of 77.52% at 2 h, and 80.76% at 4 h as well as the isolate also tolerated different concentration of NaCl and phenol. Further, the isolate was capable of colonizing intestinal epithelium cells with a strong adhesion of 44.77% for 5 h on the mucosal surface. Overall, the results conclude that Limosilactobacillus fermentum MYSAGAM1 is a potent probiotic organism with anti-fungal properties.