Characterisation of lactic acid bacteria diversity in the Maltese sheep cheese

This study explored the technological and probiotic potential of lactic acid bacteria (LAB) isolated from traditional Maltese Ġbejna and raw sheep milk. A total of 109 LAB isolates were isolated from 33 cheeses and 10 raw sheep milk samples and screened for acidification, coagulation, proteolytic and lipolytic activities, as well as tolerance to low pH, simulated gastric and pancreatic juices, autoaggregation, and surface hydrophobicity. LAB belonged to nine genera, predominated by Lactiplantibacillus , Enterococcus , and Lacticaseibacillus . Twenty-six isolates exhibited strong technological performance and survived simulated gastrointestinal conditions (50–88%). Several strains showed antimicrobial and antifungal activity against foodborne pathogens and spoilage fungi. Notably, selected L. plantarum and L. paracasei isolates combined desirable dairy functionality with probiotic-associated traits. These findings highlight the technological relevance of indigenous LAB in Ġbejna and support their potential use as adjunct cultures to enhance quality and safety of raw sheep milk cheeses. • 16S rRNA PCR identified 9 genera and 19 species of LAB. • 54 LAB isolates demonstrated strong traits essential for cheese production. • 26 LAB isolates demonstrated robust probiotic potential. • L. plantarum and L. paracasei exhibited superior technological and probiotic trait.