Technological profile and antimicrobial potential of bacteria isolated from the gut of worker Macrotermes subhyalinus (Isoptera: Termitidae)

Abstract

Lactic acid bacteria (LAB) constitute a group of microorganisms of considerable interest in food biotechnology because of their technological properties and their ability to produce a wide range of antimicrobial metabolites. The present study aimed to evaluate the technological profile and antimicrobial potential of LAB isolated from the gut of worker Macrotermes subhyalinus collected in the Lamto region (Toumodi, Côte d’Ivoire). Four strains identified by 16S rRNA gene sequencing were selected: Pediococcus acidilactici KF806466.1, Pediococcus pentosaceus KF806470.1, Lactobacillus brevis KF806467.1, and Lactobacillus plantarum KF806469.1. Their technological properties were assessed by evaluating growth under different pH values, temperatures, and NaCl concentrations, as well as their production of organic acids, acidification capacity, and bacteriocin-producing ability. Antimicrobial activity was determined using the agar well diffusion method against Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25913, and Pseudomonas aeruginosa ATCC 27853. The results showed that all four strains exhibited optimal growth at pH 6.5 and 37 °C and displayed moderate tolerance to NaCl. Chromatographic analyses revealed a diverse production of organic acids, with lactic acid being the predominant metabolite. The Pediococcus strains exhibited the highest acidification capacity and produced substantial amounts of antimicrobial substances. The inhibition zone diameters demonstrated strong antibacterial activity, particularly for P. pentosaceus and L. brevis. These findings suggest that LAB isolated from the gut of M. subhyalinus represents a promising source of biotechnologically valuable strains that could be exploited as protective cultures and biopreservative agents in food systems.