Antifungal attributes of Lactobacillus plantarum MYS6 against fumonisin producing Fusarium proliferatum associated with poultry feeds

Fumonisins, being common in occurrence in maize-based feeds, pose a great threat to animal and human health. The present study is aimed at determining the antifungal activity of Lactobacillus plantarum MYS6 against a fumonisin producing fungus, Fusarium proliferatum MYS9. The isolate was subjected to standard tests for determining its probiotic attributes and antifungal properties. L. plantarum MYS6 thrived well at pH 3.0 and 6.0, and exhibited strong resistance up to 3% bile. The isolate showed a high degree of cell surface hydrophobicity corresponding to its strong adhesion to chicken crop epithelial cells. Coinoculation with the fungus on modified de Man Rogosa Sharpe medium revealed the inhibitory effect of L. plantarum MYS6 on fungal growth and biomass. Observation using scanning electron microscopy showed distortion of hyphal structures, swollen tips and disrupted conidia. Conidia germination inhibition assay restrained germination and showed deformed hyphae. The bioprotective feature of the isolate was evident by the inhibition of fungal development in maize-kernel treated with the cell free supernatant of L. plantarum MYS6. Both the isolate and its extracellular metabolites lowered fumonisin content in feed model up to 0.505 mg/Kg of feed and 0.3125 mg/Kg of feed respectively when compared to the level of 0.870 mg/Kg of feed in control. The major antifungal compounds produced by the isolate were 10-Octadecenoic acid, methyl ester; palmitic acid, methyl ester; heptadecanoic acid, 16-methyl ester; stearic acid and lauric acid. L. plantarum MYS6 reduced 61.7% of fumonisin possibly by a binding mechanism. These findings suggest the application of L. plantarum MYS6 as an efficient probiotic additive and biocontrol agent in feed used in poultry industry. Additionally, the antifungal metabolites pose a conspicuous inhibition of Fusarium growth and fumonisin production

Effect of CFS of <i>L</i>. <i>plantarum</i> MYS6 on mycelial biomass of <i>F</i>. <i>proliferatum</i> MYS9.

<p>Effect of CFS of <i>L</i>. <i>plantarum</i> MYS6 on mycelial biomass of <i>F</i>. <i>proliferatum</i> MYS9.</p

Fumonisin removal by <i>L</i>. <i>plantarum</i> MYS6.

<p>Fumonisin removal by <i>L</i>. <i>plantarum</i> MYS6.</p

Scanning electron micrographs showing the effects of <i>L</i>. <i>plantarum</i> MYS6 and its CFS on <i>F</i>. <i>proliferatum</i> MYS9.

<p>(a, b) Control, <i>F</i>. <i>proliferatum</i> MYS9 appears to be tubular, even width, smooth surfaced hyphae and conidia showing a typical club shape-flattened base, (c, d) <i>F</i>. <i>proliferatum</i> MYS9 treated with <i>L</i>. <i>plantarum</i> MYS6 showing disrupted, wrinkled hyphae with swollen tips, (e, f) <i>F</i>. <i>proliferatum</i> MYS9 treated with CFS of <i>L</i>. <i>plantarum</i> MYS6 showing deformed, flattened and shrunken hyphae bearing disrupted conidia. Images obtained by scanning electron microscopy at 2000x magnification.</p

Growth of <i>L</i>. <i>plantarum</i> MYS6 in the presence of 2 and 3% ox gall at different time intervals.

<p>Growth of <i>L</i>. <i>plantarum</i> MYS6 in the presence of 2 and 3% ox gall at different time intervals.</p

GC/MS analysis of CFS of <i>L</i>. <i>plantarum</i> MYS-6.

<p>GC/MS analysis of CFS of <i>L</i>. <i>plantarum</i> MYS-6.</p

Molecular identification and phylogenetic analysis of the LAB.

<p>(a) Agarose gel showing amplicon (~550 bp) of 16S rRNA gene of the isolate; lane M–Marker, 100 bp ladder, lane 1 –<i>L</i>. <i>plantarum</i>MTCC 9483, lane 2—<i>L</i>. <i>plantarum</i> MYS6, (b) Phylogenetic tree based on the 16S rRNA gene sequence showing relationship between different <i>Lactobacillus</i> species. The dendrogram was constructed based on the BLAST algorithm and neighbour joining method.</p

Effect of CFS of <i>L</i>. <i>plantarum</i> MYS6 on maize kernels inoculated with <i>F</i>. <i>proliferatum</i> MYS9.

<p>Effect of CFS of <i>L</i>. <i>plantarum</i> MYS6 on maize kernels inoculated with <i>F</i>. <i>proliferatum</i> MYS9.</p

Probiotic attributes of <i>L</i>. <i>plantarum</i> MYS6.

<p>Probiotic attributes of <i>L</i>. <i>plantarum</i> MYS6.</p

Chemical composition of CFS of <i>L</i>. <i>plantarum</i> MYS6 by GC/MS analysis.

<p>Chemical composition of CFS of <i>L</i>. <i>plantarum</i> MYS6 by GC/MS analysis.</p