Functional characterization of Lactobacillus plantarum ITEM 17215: A potential biocontrol agent of fungi with plant growth promoting traits, able to enhance the nutritional value of cereal products.

Abstract

In this work, we explored the potential of 25 Lactobacillus plantarum strains isolated from cereals and milk-based products, testing characteristics related to antifungal activity and to nutritional quality. The tested strains demonstrated interesting beneficial traits, such as the ability to utilize fructo-oligosaccharides, prebiotic substances that help probiotic microorganisms to grow in the human gut, and to reduce phytate, an antinutrient present in cereal sector. Regarding mould inhibition, we highlighted the ability of the strains to inhibit Penicillium roqueforti, Mucor circinelloides and mycotoxinogenic moulds associated with cereal grains as Aspergillus flavus, A. niger, Fusarium verticillioides. Moreover, a moderate reduction of the bioavailability of aflatoxin AFB1 was detected. The selected L. plantarum strain ITEM 17215, showed a strong inhibitory ability towards fungal growth and was able to produce 1,2-dihydroxybenzene, benzoic acid, p-hydroxyphenyllactic acid and 3-phenyllactic acid. The latter compound, already described as efficient antifungal inhibitor, was the most abundant and its concentration was further increased by adding phenylalanine and phenylpyruvic acid in the growth medium. The metabolites produced by strain ITEM 17215 could also be related to the ability of the strain to induce cereal germination and promote plant growth. This aspect, not yet investigated in L. plantarum, could have interesting applications in the agro-food sector.

Keywords: 1,2-Dihydroxybenzene (PubChem CID: 289); 3-Phenyllactic acid; 3-Phenyllactic acid (PubChem CID: 3848); Acetic acid (PubChem CID: 176); Aflatoxin; Aflatoxin B1 (PubChem CID: 186907); Antifungal activity; Benzoic acid (PubChem CID: 243); Cereal sector; Lactic acid (PubChem CID: 612); Lactobacillus plantarum; Phenylalanine (PubChem CID: 6140); Phenylpyruvic acid (PubChem CID: 997); Phytate reduction; Plant-growth promoting activity; p-Hydroxyphenyllactic acid (PubChem CID: 9378).