Isolation and characterization of autochthonous lactic acid bacteria from camel milk cheese for starter culture development

Abstract

Camel milk represents a promising raw material for cheesemaking due to its high nutritional value; however, its processing is constrained by slow acidification kinetics and specific protein composition, which limit the effectiveness of conventional starter cultures developed for cow milk. This study aimed to isolate and characterize autochthonous lactic acid bacteria (LAB) from camel milk cheese and to evaluate their technological properties as potential candidates for starter culture development. Microorganisms were isolated by cultivation on selective media followed by purification. Preliminary characterization was performed based on morphological, gram-staining, and cultural characteristics, and taxonomic identification was subsequently confirmed by 16S rRNA gene sequence analysis. Acidification capacity was assessed through pH reduction and titratable acidity, while inhibitory activity of cell-free culture supernatants was evaluated against selected test cultures. Three LAB strains were isolated and identified as Lactiplantibacillus sp., Leuconostoc mesenteroides, and Streptococcus thermophilus. All isolates were gram-positive and demonstrated pronounced acid-producing activity during 48 h of incubation. Streptococcus thermophilus exhibited the highest fermentative activity, reaching pH 3.9 and titratable acidity of 120°T. Selective inhibitory activity was observed against Salmonella enteritidis, whereas no inhibitory activity was detected toward Staphylococcus aureus and Escherichia coli. The results indicate that autochthonous LAB isolated from camel milk cheese possess significant technological potential and may represent promising candidates for the future development of specialized starter cultures. Further studies on their safety, functional characteristics, and technological performance are required before practical application in camel milk cheesemaking.