Oh Seung-Eun, Heo Sojeong, Lee Gawon, Park Hee-Jung, Jeong Do-Won
Department of Food and Nutrition, Dongduk Women's University, Seoul 02748, Republic of Korea.
Department of Food and Nutrition, Sangmyung University, Seoul 03016, Republic of Korea.
Foods. 2023 Aug 9;12(16):3008. doi: 10.3390/foods12163008.
The strain DMEA09 was previously isolated from traditional Korean fermented . The objective of the current study was to investigate the traits of strain DMEA09 as a starter candidate, focusing on its safety and technological properties. Regarding its safety, the DMEA09 strain was found to be sensitive to nine antibiotics (ampicillin, chloramphenicol, erythromycin, gentamicin, kanamycin, streptomycin, tetracycline, tylosin, and vancomycin) by showing lower minimum inhibitory concentrations (MICs) than the cut-off values suggested by the European Union Food Safety Authority for these nine antibiotics. However, its MIC value for clindamycin was twice as high as the cut-off value. A genomic analysis revealed that strain DMEA09 did not encode the acquired antibiotic resistance genes, including those for clindamycin. The DMEA09 strain did not show hemolysis as a result of analyzing α- and β-hemolysis. It did not form biofilm either. A genomic analysis revealed that strain DMEA09 did not encode for any virulence factors including hemolysin. Most importantly, multilocus sequence typing revealed that the clonal group of strain DMEA09 was distinguished from clinical isolates. Regarding its technological properties, strain DMEA09 could grow in the presence of 6% salt. It showed protease activity when the salt concentration was 3%. It did not exhibit lipase activity. Its genome possessed 37 putative protease genes and salt-tolerance genes for survivability under salt conditions. Consequently, strain DMEA09 shows safe and technological properties as a new starter candidate. This was confirmed by genome analysis.
菌株DMEA09先前是从韩国传统发酵食品中分离出来的。本研究的目的是调查菌株DMEA09作为候选发酵剂的特性，重点关注其安全性和技术特性。关于其安全性，发现DMEA09菌株对九种抗生素（氨苄青霉素、氯霉素、红霉素、庆大霉素、卡那霉素、链霉素、四环素、泰乐菌素和万古霉素）敏感，其最低抑菌浓度（MIC）低于欧盟食品安全局针对这九种抗生素建议的临界值。然而，其对克林霉素的MIC值是临界值的两倍。基因组分析表明，菌株DMEA09不编码包括克林霉素抗性基因在内的获得性抗生素抗性基因。通过分析α-溶血和β-溶血，DMEA09菌株未表现出溶血现象。它也不形成生物膜。基因组分析表明，菌株DMEA09不编码任何毒力因子，包括溶血素。最重要的是，多位点序列分型表明，菌株DMEA09的克隆群与临床分离株不同。关于其技术特性，菌株DMEA09在6%盐存在的情况下能够生长。当盐浓度为3%时，它表现出蛋白酶活性。它没有表现出脂肪酶活性。其基因组拥有37个假定的蛋白酶基因和在盐条件下生存的耐盐基因。因此，菌株DMEA09作为一种新的候选发酵剂显示出安全和技术特性。这通过基因组分析得到了证实。
