• Journal of Microbiology and Biotechnology
• /
• v.33 no.12
• /
• pp.1625-1634
• /
• 2023

Leuconostoc lactis strain DMLL10 was isolated from kimchi, a fermented vegetable, as a starter candidate through safety and technological assessments. Strain DMLL10 was susceptible to ampicillin, chloramphenicol, clindamycin, erythromycin, gentamicin, kanamycin, streptomycin, and tetracycline. It did not show any hemolytic activity. Regarding its phenotypic results related to its safety properties, genomic analysis revealed that strain DMLL10 did not encode for any toxin genes such as hemolysin found in the same genus. It did not acquire antibiotic resistance genes either. Strain DMLL10 showed protease activity on agar containing NaCl up to 3%. The genome of DMLL10 encoded for protease genes and possessed genes associated with hetero- and homo-lactic fermentative pathways for lactate production. Finally, strain DMLL10 showed antibacterial activity against seven common foodborne pathogens, although bacteriocin genes were not identified from its genome. These results indicates that strain DMLL10 is a novel starter candidate with safety, enzyme activity, and bacteriocin activity. The complete genomic sequence of DMLL10 will contribute to our understanding of the genetic basis of probiotic properties and allow for assessment of the effectiveness of this strain as a starter or probiotic for use in the food industry.

• Journal of Microbiology and Biotechnology
• /
• v.34 no.9
• /
• pp.1803-1809
• /
• 2024

Leuconostoc lactis DMLL10 is a microorganism specific to kimchi fermentation. In this study, we sought to evaluate the toxicity of this strain, which was newly isolated from kimchi, to determine its safety as a food ingredient. Bacterial reverse mutation assay, chromosomal aberration assay, and mammalian cell in vitro micronucleus assay were performed to assess the genetic toxicity of Leu. lactis DMLL10. The strain did not induce mutagenicity in Salmonella typhimurium TA98, TA100, TA1535, TA1537, or Escherichia coli WP2uvrA, with or without metabolic activation of S9 mixture. The oral administration of Leu. lactis DMLL10 also did not significantly increase the number of micronucleated polychromatic erythrocytes, or the mean ratio of polychromatic to total erythrocytes. Additionally, Leu. lactis DMLL10 did not cause a significant chromosomal aberration in CHU/IL cells in the presence or absence of S9 activation. Therefore, Leu. lactis DMLL10 can be suggested as a functional food ingredient with reliability and safety.