ANTIFUNGAL AND ANTIBACTERIAL ACTIVITY OF SOME LACTOBACILLI ISOLATED FROM CAMEL'S MILK BIOTOPE IN THE SOUTH OF ALGERIA

Antifungal activity has been the subject of numerous recent works to fight the development of molds in food products and to reduce alteration. The objective of this study is the detection of new indigenous lactic acid bacteria (LAB) strains isolated from Algerian camel's milk which have an antifungal activity. A number of 264 LAB were isolated from fermented camel's milk where 80 rods isolates were identified by phenotypical, physiological and biochemical tests. All retained isolates belong to the genus Lactobacillus (Lb.). The antifungal activity was determined by using confrontation and overlay techniques. The screening of antifungal activity against Aspergillus niger, Aspergillus fumigatus and Penicillium sp. showed that 14 strains have an antifungal activity. These later isolates were identified as Lb. plantrarum, Lb. paracasei subsp. paracasei, Lb. brevis, Lb. rhamnosus and Lb. pentosus. These strains have shown an effect on mycelial growth and spore germination. Penicillium sp. is the most inhibited followed by Aspergillus ssp. No inhibitory activity could be detected against fungi with the supernatant. However, supernatant have an inhibitory activity against Escherichia coli, P seudomonas aeruginosa, Staphylococcus aureus and Listeria ivanovii. P. aeruginosa is the only specie who has been affected by the neutralized supernatant. The redissolved dry supernatant of Lb. brevis revealed an inhibition of both fungal and bacterial indicator strains. Results suggest that camel's milk LAB's strains could be selected for application to control spoilage, fungal growth and pathogenic bacteria. The use of LAB producing antifungal metabolites represents a technological advantage for the food industry.