Distribution and antimicrobial activity of lactic acid bacteria from raw camel milk

Abstract

Consumer demand for natural pathogen-control agents for substitution of synthetic food preservatives and traditional antibiotics is increasing. This study aimed to reveal the distribution of lactic acid bacteria (LAB) in raw camel milk and to characterize their antimicrobial traits. The genetic identification by 16S rRNA sequencing of 58 LAB isolates showed the predominance of Enterococcus (24.2%), Lactococcus (22.4%) and Pediococcus (20.7%) genera in raw camel milk. These genera exhibited inhibitory activity against a broad spectrum of Gram-positive and Gram-negative bacteria including multidrug-resistant Salmonella . Among these LAB, two isolates—identified as Pediococcus pentosaceus CM16 and Lactobacillus brevis CM22—were selected for their strong bacteriocinogenic anti-listerial activity estimated at 1600 and 800 AU/mL, respectively. The bacteriocins produced were partially purified by ammonium sulphate precipitation and gel filtration and then biochemically characterized. The proteinaceous nature of bacteriocins was confirmed by the susceptibility to enzymes. These bacteriocins showed significant technological characteristics such as heat-resistance, and stability over a wide range of pH (2.0–10.0). In conclusion, these results indicated that Pediococcus pentosaceus CM16 and Lactobacillus brevis CM22 could be useful as potential probiotics. Moreover, their partially purified bacteriocins may play an important role as food preservatives and feed additives. To our knowledge, this is the first report describing the distribution of LAB population in raw camel milk and the characterization of their bacteriocins from the Arabian Peninsula of western Asia.

Molecular detection, phylogenetic analysis, and antibacterial performance of lactic acid bacteria isolated from traditional cheeses, North‐West Iran

“…revealed strong antibacterial activity than isolates with RFLP pattern I that consist of Enterococcus subsp. Similar results were reported on antibacterial activity of LAB isolated from raw camel milk (Rahmeh et al., 2019), Genestoso cheese (González et al., 2007) and Brazilian artisanal cheeses (Margalho et al., 2020). Organic acids production, as the main antibacterial agents, by LAB is mainly a genus‐specific phenomenon and partially specie‐specific.…”

Functional and Genomic Characterization of Ligilactobacillus salivarius TUCO-L2 Isolated From Lama glama Milk: A Promising Immunobiotic Strain to Combat Infections

“…The Lactobacillus acidophilus AA105 strain from camel milk is a potent inhibitor of Salmonella paratyphi, Shigella spp., and pathogenic E. coli (Abo-Amer, 2013), and L. brevis CM22 demonstrated inhibitory effects against Listeria spp. (Rahmeh et al, 2019). Interestingly, a recent report of Elbanna et al (2018) showed that L. paracasei Pro4 and L. rhamnosus Pro7 isolated from fermented camel milk modulate the intestinal immunity after oral administration in mice by improving the expression of Toll-like receptor (TLR)-2, interferon (IFN)-γ, and secretory immunoglobulin A (IgA) indicating that LAB isolated from the milk of camelids can be beneficial modulators of the immune system.…”

Data on the diversity of lactic acid bacteria isolated from raw and fermented camel milk

“…Fermented camel milk, named shubat, is also known for its medicinal and dietary properties [2] . LAB is the dominant population in raw and fermented milk; they produce various antimicrobials such as organic acids and hydrogen peroxide, antifungal peptides and bacteriocins and play a crucial role in food fermentation processes [3] . The isolation and characterization of resident LAB in raw and fermented camel milk are essential for further development starters of functional camel-milk-derived products.…”