Preliminary study on the antagonistic effect of lactic acid bacteria isolated from dried and salted camel meat (Kadid) – A traditional processed meat product from Southwestern Algeria – against selected microbial contaminants

Abstract

Camel meat, as a food source, contributes significantly to achieving food security in the southern regions of Algeria. It is used to prepare a traditionally processed meat, known locally as ‘Kadid’, which involves drying fresh camel meat in the open air to extend its shelf life. This preservation ability is attributed to several factors, including not only physicochemical parameters, but also microbial factors. This study aims to evaluate the antagonistic effect of lactic acid bacteria (LAB) strains, isolated from Kadid, against selected microbial contaminants. LAB strains and microbial contaminants were isolated using the spread plate technique on appropriate agar media for each microbial group. After purification, microbial contaminants were identified through a series of biochemical tests and then subjected to susceptibility testing on Mueller-Hinton agar using the Kirby-Bauer disc diffusion method. The in vitro evaluation of the antibacterial effect of the LAB isolates was conducted by spot testing, while the antifungal effect was assessed using the mycelial radial growth method on agar and the biomass method in a broth medium. A total of 13 microbial contaminants and 9 LAB strains were isolated. Bacterial contaminants showed variable antibiotic susceptibility between strains. Several antibiotics tested have retained their antibacterial action. Most of the isolated LAB strains showed positive proteolytic activity (5/9, i.e., 55.5%), and good acidifying power, with lactic acid production ranging from 1.86 to 3.24g/L. This acidifying ability is likely the source of the moderate to strong antibacterial effect of the LAB strains. Additionally, the LAB strains exhibited an antifungal effect, with inhibition rates of radial growth ranging from 5% to 25%. Dried and salted camel meat can serve as a source of LAB strains with valuable technological properties, making them suitable for use in fermentation industries and other applications.