In the present study, metabolic characteristics, such as lactic acid, hydrogen peroxide, exopolysaccharide (EPS) production, and antimicrobial activities, of 17 Enterococcus faecium isolates from white cheese samples were assessed. In E. faecium isolates, the amount of lactic acid obtained between in MRS medium 0.61-1.22% and in skim milk 0.75-1.08%, and the amount of H2O2 was found between 0.57 and 3.17 µg mL-1. In MRS and skim milk, the amount of EPS production was 59-185 mg L-1, 155-255 mg L-1 for isolates, respectively. The antimicrobial activities of E. faecium isolates on eight different pathogenic bacteria were also performed by an agar well diffusion method. The highest inhibition zones 8.60 mm were observed with culture supernatants of RI-71 isolate against Escherichia coli ATCC 35218. The safety of the E. faecium isolates was assessed by determining gelatinase activity, hemolytic activity, the resistance to ten different antibiotics, biofilm forming, and virulence genes (van A, van B, gelE, cylA, cylB, esp, agg, and asa1, efaAfm, cob, ccf, hyl). The isolates did not show gelatinase activity, β-hemolysis, and biofilm formation. All E. faecium isolates were susceptible to vancomycin, penicillin-G, tetracycline, ampicillin, and chloramphenicol. The efaAfm gene was detected most frequently (94%) followed by cob (82%), van B (59%), and ccf (53%). For enterococci to be recommended as co-starter or probiotic adjunct cultures, it is necessary to determine whether they have virulence genes and resistance to antibiotics.

中文翻译：

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17 株屎肠球菌分离株的安全性和代谢特征。

在本研究中，评估了来自白干酪样品的 17 种屎肠球菌分离物的代谢特征，例如乳酸、过氧化氢、胞外多糖 (EPS) 的产生和抗菌活性。在屎肠球菌分离物中，获得的乳酸量介于 MRS 培养基中的 0.61-1.22% 和脱脂牛奶中的 0.75-1.08% 之间，并且发现 H2O2 的量介于 0.57 和 3.17 µg mL-1 之间。在 MRS 和脱脂牛奶中，分离株的 EPS 产量分别为 59-185 mg L-1、155-255 mg L-1。屎肠球菌分离株对八种不同病原菌的抗菌活性也通过琼脂井扩散法进行。在针对大肠杆菌 ATCC 35218 的 RI-71 分离株的培养上清液中观察到最高抑菌圈 8.60 mm。通过测定明胶酶活性、溶血活性、对十种不同抗生素的抗性、生物膜形成和毒力基因（van A、van B、gelE、cylA、cylB、esp、agg 和 asa1、efaAfm、cob、ccf）评估粪便分离物, hyl)。分离株没有显示明胶酶活性、β-溶血和生物膜形成。所有屎肠球菌分离株都对万古霉素、青霉素-G、四环素、氨苄青霉素和氯霉素敏感。efaAfm 基因的检测频率最高 (94%)，其次是 cob (82%)、van B (59%) 和 ccf (53%)。如果肠球菌被推荐为共同起始物或益生菌辅助培养物，则有必要确定它们是否具有毒力基因和对抗生素的耐药性。和毒力基因（van A、van B、gelE、cylA、cylB、esp、agg 和 asa1、efaAfm、cob、ccf、hyl）。分离株没有显示明胶酶活性、β-溶血和生物膜形成。所有屎肠球菌分离株都对万古霉素、青霉素-G、四环素、氨苄青霉素和氯霉素敏感。efaAfm 基因的检测频率最高 (94%)，其次是 cob (82%)、van B (59%) 和 ccf (53%)。如果肠球菌被推荐为共同起始物或益生菌辅助培养物，则有必要确定它们是否具有毒力基因和对抗生素的耐药性。和毒力基因（van A、van B、gelE、cylA、cylB、esp、agg 和 asa1、efaAfm、cob、ccf、hyl）。分离株没有显示明胶酶活性、β-溶血和生物膜形成。所有屎肠球菌分离株都对万古霉素、青霉素-G、四环素、氨苄青霉素和氯霉素敏感。efaAfm 基因的检测频率最高 (94%)，其次是 cob (82%)、van B (59%) 和 ccf (53%)。如果肠球菌被推荐为共同起始物或益生菌辅助培养物，则有必要确定它们是否具有毒力基因和对抗生素的耐药性。efaAfm 基因的检测频率最高 (94%)，其次是 cob (82%)、van B (59%) 和 ccf (53%)。如果肠球菌被推荐为共同起始物或益生菌辅助培养物，则有必要确定它们是否具有毒力基因和对抗生素的耐药性。efaAfm 基因的检测频率最高 (94%)，其次是 cob (82%)、van B (59%) 和 ccf (53%)。如果肠球菌被推荐为共同起始物或益生菌辅助培养物，则有必要确定它们是否具有毒力基因和对抗生素的耐药性。