008: Antimicrobial Effect of Microfiltrates From Aguamiel Fermented With Lactiplantibacillus Plantarum and Bacillus Mojavensis

Introduction

Aguamiel is the sap extracted from the maguey plants, and its chemical composition allows it to serve as a substrate for lactic acid bacteria (LAB) during either homolactic or heterolactic fermentation. The aim of this study was to evaluate the effect of microfiltrates from the fermentation of Lactiplantibacillus plantarum and Bacillus mojavensis, using aguamiel from the municipality of Singuilucan, Hidalgo, as a substrate, against three medically important pathogenic bacteria.

Methods

The aguamiel was adjusted to 10° Brix and pasteurized for 30 minutes at 80°C. It was then inoculated with L. plantarum and B. mojavensis and allowed to ferment for 48 hours at 37°C. After fermentation, the samples were passed through 0.22 μm filters to obtain the filtrates from each strain. The Kirby-Bauer method was employed, with 10 μL of each filtrate placed on discs, which were then inoculated on plates with E. coli 25922, Salmonella enteritidis 13076, and S. aureus 25923. In addition, the inhibition effect was tested using a microplate assay, where 20 μL of the filtrates + sterile broth were added and four dilutions were performed. Finally, 5 μL of the pathogenic bacteria were added, adjusting the final volume to 200 μL. FT-IR analysis was performed using a Frontier SP8000–FTIR system, with 250 μL of each filtrate measured in the 400-4000 cm^-1 range.

Results

Inhibition halos were observed in all three pathogenic strains, ranging from 80 to 100 mm. Regarding the percentage of inhibition by the filtrates, the highest inhibition was observed for S. aureus with 90% inhibition for both L. plantarum and B. mojavensis, followed by E. coli with 85% inhibition, and 75% inhibition for Salmonella. In the FT-IR spectra, bands between 700 and 1000 cm^-1 were observed, representing glucose, fructose, and sucrose, while the band at 1700 cm^-1 indicated AGCC (acetate group), and a band at 3,000 cm^-1 was attributed to inulin in both filtrates.

Significance

The use of microfiltrates from aguamiel fermented with Lactiplantibacillus plantarum and Bacillus mojavensis could offer a natural and effective alternative for controlling pathogenic bacteria and promoting a healthy environment in the intestinal microbiota of the consumer.

Authors: Adelfo García-Ceja, Arely León López, Rosa Isela Ortiz Basurto, Maribel Jiménez Fernández, Beatriz Pérez Armendáriz