Antifungal activity of human gut lactic acid bacteria against aflatoxigenic Aspergillus flavus MTCC 2798 and their potential application as food biopreservative

Abstract

With the enhanced use of chemical preservatives and the survival of foodborne pathogens, lactic acid bacteria and its metabolic product have received increased attention as a potential food preservative. Even though the antibacterial property of lactic acid bacteria is well known, its antifungal property and application in food preservation have not been widely exploited. Considering these facts, this study was conducted to investigate the antifungal properties of three human gut lactic acid bacterial isolates, Lactobacillus plantarum AL1, Lactobacillus fermentum AL2, and Weissella confusa AL3 antifungal activity of the isolates were studied against the aflatoxigenic Aspergillus flavus MTCC 2798, using the agar overlay method and inhibition of fungal mycelium (co-culture method). These LAB isolates were also potent producers of antimicrobial compounds like lactic acid, hydrogen peroxide, and diacetyl. GC-MS analysis of the methanolic extract of the three LAB isolates detected two antifungal bioactive compounds like cyclo (leucyloprolyl) and 1,2-benzenedicarboxylic acid in extracts. The hemolysis results provided an important insight that the human gut lactic acid bacteria can be used as protective cultures in the biopreservation. The antifungal activity of human gut LAB AL1, AL2, and AL3 against aflatoxigenic Aspergillus flavus MTCC 2798 and its ability extend the shelf life of peanuts prove as a natural preservative for food products. | INTRODUCTIONFood spoilage is described as an alteration in the quality of food that makes it unpleasant and unfit for consumption either by spoilage microorganisms for animals and humans (Odeyemi, Alegbeleye, Strateva, & Stratev, 2020). Despite the development of technological innovation in food science and technology for many years, spoilage of food remains as a global issue and experience huge economic losses from producers to consumers (Snyder & Worobo, 2018). Apart from the complication of food humility and financial loss spoiled food also come up with food waste, which is another universal environmental problem.Food and animal feed contamination by fungi especially by mycotoxigenic fungi, is a global concern for food manufacturers.Mycotoxins are toxic secondary metabolites produced by fungi, which in turn poses serious health concerns, some of which present considerable food safety challenges. Contamination by aflatoxin produced by Aspergillus parasiticus, Aspergillus flavus, and Aspergillus nomius, is one of the highest risks of stored feed. Aflatoxin has a serious impact on human and livestock causing both acute and chronic toxicity such as immunosuppression, hepatotoxicity, teratogenicity, and cancers, which threaten public health and may lead to death (Kumar, Mahato, Kamle, Mohanta, & Kang, 2017). Aflatoxin B1 is the most dangerous and categorized as class IIa carcinogen by the

Extraction and characterization of bioactive secondary metabolites from lactic acid bacteria and evaluating their antifungal and antiaflatoxigenic activity

“…Similar results were reported by Parappilly et al. [64] , who revealed that all three methanolic extracts of the isolates ( L. plantarum AL1, L. fermentum AL2, and Weissella confusa AL3) showed very high inhibitory activity towards aflatoxigenic A. flavus MTCC 2798. The antifungal action of L. rhamnosus ethyl acetate extract No.…”

Antagonistic activity of Trichoderma asperellum against Fusarium species, chemical profile and their efficacy for management of Fusarium‐root rot disease in dry bean

“…55,56 Other bioactive compounds of T. asperellum extracts butylated hydroxytoluene, cyclo(L-prolyl-Lvaline), cyclo(leucyloprolyl), 9-octadecenoic acid, and hydroquinone were mentioned to exert antifungal activity against wide range of fungal plant pathogens and mycotoxigenic fungi in previous studies. 57 Nofal et al 58 reported that globulol exhibited high antifungal activity against F. graminearum, A. solani and R. solani.…”

The Antibacterial and Larvicidal Potential of Bis-(2-Ethylhexyl) Phthalate from Lactiplantibacillus plantarum

“…Anju et al [ 25 ] had reported the identification of BEHP as one of the metabolites produced by a nematode symbiotic bacterium associated with a novel entomopathogenic nematode Rhabditis species. Previously, authors have reported that L. plantarum also produce such types of metabolites, e.g., diisooctyl phthalate [ 39 ]. However, no specific results have been reported on the isolation of Bis-(2-ethylhexyl) phthalate (BEHP); hence, the current report describes the isolation and characterization of BEHP from L. plantarum BCH-1 for the first time.…”