Polyphasic characterization of Enterococcus strains isolated from traditional Moghan cheese in Iran

Abstract

Traditional Moghan cheese is made from unpasteurized milk in the rural areas and nomadic tribes of Moghan region in Iran. In this study, we used a simple and rapid method for isolation of acid resistant lactic acid bacteria from traditional Moghan cheese. The six distinct isolates differentiated based on RAPD‐PCR were identified as members of Enterococcus faecium, E. faecalis, and E.durans species using classical phenotypic and biochemical tests as well as molecular methods. Based on the antibiotic susceptibility, the isolates were classified as resistant, intermediate, and sensitive. Cell‐free culture supernatants of isolates showed different antagonistic activity against the growth of some spoilage and food‐borne pathogens at two natural and neutralized pH conditions. Considering their tolerance to acid and bile, antagonistic effects on some spoilage and food‐borne pathogens and susceptibility to vancomycin, E. faecium strain ABRIINW.M (isolate IE2) and E. faecium strain ABRIINW.N (isolate FE1) are proposed as adjunct cultures to prevent the growth of spoilage and food‐borne pathogens. Practical applications This study aimed to provide the first data on prevalence, acquired antibiotic‐resistance, and probiotic potential of Enterococcus spp. isolated from Moghan cheese in Iran. Such observations contribute to understanding the functional characteristics of Enterococci isolated from Moghan cheese. We also showed that polyphasic characterization of Enterococci provides significant information for species assignment and could be used as a strategy to differentiate between strains of isolates. The results of our study provide a useful setting for further investigations on antibiotic‐resistance and antimicrobial activity of Moghan cheese Enterococci as well as evaluation of their technological activities and probiotic potential.

Evaluation of the probiotic, technological, safety attributes, and GABA-producing capacity of microorganisms isolated from Iranian milk kefir beverages

“…With regard to phenotypic, biochemical, and physiological characteristics of the isolates, results of the present study were consistent with previous studies, but there were some differences in sugar fermentation patterns which is because of the difference between studied strains (Leite et al, 2015;Hejazi et al, 2019;Hurtado-Romero et al, 2021). For example, Hejazi et al (2019), reported that E. faecalis isolated from cheese was unable to ferment saccharose, while E. faecalis in the present study fermented it (Hejazi et al, 2019).…”

“…With regard to phenotypic, biochemical, and physiological characteristics of the isolates, results of the present study were consistent with previous studies, but there were some differences in sugar fermentation patterns which is because of the difference between studied strains (Leite et al, 2015;Hejazi et al, 2019;Hurtado-Romero et al, 2021). For example, Hejazi et al (2019), reported that E. faecalis isolated from cheese was unable to ferment saccharose, while E. faecalis in the present study fermented it (Hejazi et al, 2019). Since an important principle about the effectiveness of probiotics is that they have to reach the target organ-the large intestine-alive and reproducible, they must be able to cope with the high acidity and alkaline pH, bile salts as well as gastric and intestinal juice in the digestive tract (Barzegar et al, 2021).…”

Technological potential of native lactic acid bacteria isolated from Swiss-type artisanal cheese (Ancash, Peru) for their application in food

“…Taxonomic identification of the cheese microbiota generally uses physiological, phenotypic and biochemical methods, but species levels are sometimes not reached (Hassanzadazar et al, 2017;Sharma et al, 2020). Molecular tools, such as 16 s rDNA sequencing, are applied to taxonomically identify the cheese-associated bacterial species (Hejazi et al, 2019;Hajigholizadeh et al, 2020). The unknown diversity of LAB in artisanal cheese and other fermented foods is attractive to the food industry because native bacterial species could be used to improve the nutritional, technological, and safety characteristics of different foods, also increasing their shelf life (Chen et al, 2008;Ashaolu, 2019).…”