Dataset Information

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.

SUBMITTER: Rahmeh R

PROVIDER: S-EPMC6522851 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

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

Rahmeh R R Akbar A A Kishk M M Al-Onaizi T T Al-Azmi A A Al-Shatti A A Shajan A A Al-Mutairi S S Akbar B B

New microbes and new infections 20190418

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 g ...[more]

PMID: 31193267

Similar Datasets

Project description:Dairy products play a crucial role in human nutrition as they provide essential nutrients. However, the presence of diverse microorganisms in these products can pose challenges to food safety and quality. Here, we provide a comprehensive molecular characterization of a diverse collection of lactic acid bacteria (LAB) and staphylococci isolated from raw sheep's milk. Whole-genome sequencing, phenotypic characterization, and bioinformatics were employed to gain insight into the genetic composition and functional attributes of these bacteria. Bioinformatics analysis revealed the presence of various genetic elements. Important toxin-related genes in staphylococci that contribute to their pathogenic potential were identified and confirmed using phenotypic assays, while adherence-related genes, which are essential for attachment to host tissues, surfaces in the dairy environment, and the creation of biofilms, were also present. Interestingly, the Staphylococcus aureus isolates belonged to sequence type 5, which largely consists of methicillin-susceptible isolates that have been involved in severe nosocomial infections. Although genes encoding methicillin resistance were not identified, multiple resistance genes (RGs) conferring resistance to aminoglycosides, macrolides, and fluroquinolones were found. In contrast, LAB had few inherently present RGs and no virulence genes, suggesting their likely safe status as food additives in dairy products. LAB were also richer in bacteriocins and carbohydrate-active enzymes, indicating their potential to suppress pathogens and effectively utilize carbohydrate substrates, respectively. Additionally, mobile genetic elements, present in both LAB and staphylococci, may facilitate the acquisition and dissemination of genetic traits, including RGs, virulence genes, and metabolic factors, with implications for food quality and public health. The molecular and phenotypic characterization presented herein contributes to the effort to mitigate risks and infections (e.g., mastitis) and enhance the safety and quality of milk and products thereof.

Project description:Lactic acid bacteria (LAB) have long been consumed by people in several fermented foods such as dairy products. A study was conducted on lactating dairy cows to isolate and characterize LAB from dairy products found in and around Bahir-Dar city, North Western Ethiopia. Milk and milk products were randomly collected from dairy farms, milk vending shops, individual households, and supermarkets for bacteriological investigations. A total of sixteen samples were taken from different sources and cultured on different selective media: de Man, Rogosa, and Sharpe (MRS) agar for Lactobacillus spp.; M17 agar for Lactococcus spp.; Rogasa SL agar for Streptococci spp.; and MRS supplemented with cysteine (0.5%) for Bifidobacteria spp. Different laboratory techniques were implemented for LAB isolation and identification. A total of 41 bacterial isolates were grouped under five different genera of LAB and Bifidobacteria spp. were identified based on the growth morphology on the selective media, growth at a different temperature, gas production from glucose, carbohydrate fermentation, and other biochemical tests. LAB genera such as Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, Streptococcus, and Bifidobacterium spp. were isolated and identified from raw milk, cheese, and yogurt. Based on the current study, the majority of the LAB (24.38%) was isolated from cheese and yogurt. Among these, Lactobacillus, Lactococcus (21.94%), Streptococcus (19.51%), Leuconostoc (14.64%), Bifidobacteria (12.19%), and Pediococcus (7.31%) spp. were also identified from these products. Furthermore, based on the bacterial load count and different identification methodologies, our study revealed that Lactobacillus spp. were the dominant LAB isolated from milk and milk products. As a result, since there are few studies on the isolation and identification of lactic acid bacteria from dairy products in Ethiopia, more research studies are needed to complete the identification and characterization to species level and their possible role as probiotics.

Dataset Information

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

Publications

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

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets