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Nam Soo Han - One of the best experts on this subject based on the ideXlab platform.

  • Development of Leuconostoc Lactis –Specific Quantitative PCR and its Application for Identification and Enumeration in Fermented Foods
    Food Analytical Methods, 2020
    Co-Authors: Seul-ah Kim, Jae-han Bae, Hyunbin Seong, Nam Soo Han
    Abstract:

    Leuconostoc Lactis plays a pivotal role in providing a pleasant aroma in fermented foods. In this study, an L. Lactis-specific quantitative PCR (qPCR) method was developed by designing species-specific primers using comparative pan-genomic analysis to monitor the microbial populations during food fermentation. As a result, a hypothetical protein-encoding gene, Llac_03470, was selected as a target gene to detect L. Lactis using a designed set of primers (NlacF and NlacR). PCR analysis against genomic DNA of various lactic acid bacteria confirmed the specificity of the primers for the detection of genomic DNA of L. Lactis strains. By using the primer set, a standard curve for qPCR analysis of L. Lactis was established, and no significant differences (p 

  • development of Leuconostoc Lactis specific quantitative pcr and its application for identification and enumeration in fermented foods
    Food Analytical Methods, 2020
    Co-Authors: Seul-ah Kim, Jae-han Bae, Hyunbin Seong, Nam Soo Han
    Abstract:

    Leuconostoc Lactis plays a pivotal role in providing a pleasant aroma in fermented foods. In this study, an L. Lactis-specific quantitative PCR (qPCR) method was developed by designing species-specific primers using comparative pan-genomic analysis to monitor the microbial populations during food fermentation. As a result, a hypothetical protein-encoding gene, Llac_03470, was selected as a target gene to detect L. Lactis using a designed set of primers (NlacF and NlacR). PCR analysis against genomic DNA of various lactic acid bacteria confirmed the specificity of the primers for the detection of genomic DNA of L. Lactis strains. By using the primer set, a standard curve for qPCR analysis of L. Lactis was established, and no significant differences (p < 0.05) were found in the yields of the genomic DNA recovered from MRS medium and kimchi. In addition, the qPCR was validated to successfully enumerate L. Lactis during kimchi fermentation. In conclusion, the newly developed qPCR method in this study can be used to detect L. Lactis in fermented kimchi and to monitor the change in its population during the fermentation process.

  • Genome sequence analysis of potential probiotic strain Leuconostoc Lactis EFEL005 isolated from kimchi
    Journal of Microbiology, 2015
    Co-Authors: Jin Seok Moon, Hye Sun Choi, So Yeon Shin, Sol Ji Noh, Che Ok Jeon, Nam Soo Han
    Abstract:

    Leuconostoc Lactis EFEL005 (KACC 91922) isolated from kimchi showed promising probiotic attributes; resistance against acid and bile salts, absence of transferable genes for antibiotic resistance, broad utilization of prebiotics, and no hemolytic activity. To expand our understanding of the species, we generated a draft genome sequence of the strain and analyzed its genomic features related to the aforementioned probiotic properties. Genome assembly resulted in 35 contigs, and the draft genome has 1,688,202 base pairs (bp) with a G+C content of 43.43%, containing 1,644 protein-coding genes and 50 RNA genes. The average nucleotide identity analysis showed high homology (≥ 96%) to the type strain L. Lactis KCTC3528, but low homology (≤ 95%) to L. Lactis KCTC3773 (formerly L. argentinum ). Genomic analysis revealed the presence of various genes for sucrose metabolism (glucansucrases, invertases, sucrose phosphorylases, and mannitol dehydrogenase), acid tolerance (F1F0 ATPases, cation transport ATPase, branched-chain amino acid permease, and lysine decarboxylase), vancomycin response regulator, and antibacterial peptide (Lactacin F). No gene for production of biogenic amines (histamine and tyramine) was found. This report will facilitate the understanding of probiotic properties of this strain as a starter for fermented foods.

Hitoshi Kondo - One of the best experts on this subject based on the ideXlab platform.

Hitomi Ohara - One of the best experts on this subject based on the ideXlab platform.

  • Xylooligosaccharide fermentation with Leuconostoc Lactis.
    Journal of bioscience and bioengineering, 2006
    Co-Authors: Hitomi Ohara, Michiko Owaki, Kenji Sonomoto
    Abstract:

    Strains of Leuconostoc Lactis SHO-47 and Le. Lactis SHO-54, producing the clinically useful enzyme NAD-specific 6-phosphoglucanate dehydrogenase, were cultivated with a hydrolyzed birch wood xylan as the unique carbon source to produce D-lactic acid for poly(D-lactic acid). In addition to the strains SHO-47 and SHO-54, Lactococcus Lactis IO-1, well known as a good xylose-utilizing lactic acid bacterium, was used as a control to confirm the extent of hemicellulose hydrolysis. The fermentation time for lactic acid of strains SHO-47 and SHO-54 was 12 h, and produced respectively 2.3 and 2.2 g/l lactic acid from 8.5 g/l hydrolyzed xylan, whereas the fermentation time of strain IO-1 was 21 h, and produced 1.3 g/l lactic acid. Xylooligosaccharides from xylobiose to xylohexose were utilized more rapidly than xylose in the cultures of strains SHO-47 and SHO-54. However, xylose concentration increased temporarily and then decreased in the culture of strain IO-1. On the other hand, xylooligosaccharides larger than xyloheptaose were not utilized by these three strains. The xylosidase activities of SHO-47, SHO-54, and IO-1 were induced by xylose or a mixture of xylobiose and xylotriose. The xylosidases of these three strains were localized in their cytoplasm.

  • Purification and characterization of NAD-specific 6-phosphogluconate dehydrogenase from Leuconostoc Lactis SHO-54.
    Journal of bioscience and bioengineering, 2004
    Co-Authors: Hitomi Ohara, Roy A. Russell, Kazuyuki Uchida, Hitoshi Kondo
    Abstract:

    The 6-phosphogluconate dehydrogenase (EC 1.1.1.44) from Leuconostoc Lactis SHO-54 was purified with an overall yield of 38% and a specific activity of 140.0 units/mg protein. The enzyme had a tetrameric structure and a molecular mass of 32.8 kDa. The amino acid composition of the purified enzyme was determined, and the enzyme contained no sulfhydryl amino acids. The Km values for 6-phosphogluconate and NAD were 0.95 mM and 0.32 mM, respectively.

Leon M. T. Dicks - One of the best experts on this subject based on the ideXlab platform.

Franco Dellaglio - One of the best experts on this subject based on the ideXlab platform.

  • Reclassification of Leuconostoc argentinum as a later synonym of Leuconostoc Lactis.
    International journal of systematic and evolutionary microbiology, 2006
    Co-Authors: Marc Vancanneyt, Medana Zamfir, Marjan De Wachter, Ilse Cleenwerck, Bart Hoste, Franca Rossi, Franco Dellaglio, Luc De Vuyst, Jean Swings
    Abstract:

    Leuconostoc argentinum, Leuconostoc Lactis and ten related strains from Romanian dairy products formed a single cluster, clearly separated from other Leuconostoc species, after numerical analysis of repetitive extragenic palindromic-PCR patterns, whole-cell protein profiles (SDS-PAGE) and fluorescent amplified fragment length polymorphism (FAFLP) band patterns. 16S rRNA gene sequence analysis confirmed a very high similarity between both type strains and representative dairy isolates (>99.6 %). DNA-DNA hybridization experiments revealed high relatedness values between the type strains of L. argentinum and L. Lactis and between these strains and representative Romanian strains. These data and the lack of phenotypic distinctive characteristics demonstrate that L. argentinum and L. Lactis are synonymous.

  • Leuconostoc argentinum sp. nov., isolated from Argentine raw milk
    International Journal of Systematic Bacteriology, 1993
    Co-Authors: Leon M. T. Dicks, L. Fantuzzi, M. Du Toit, F. C. Gonzalez, Franco Dellaglio
    Abstract:

    The levels of genotypic relatedness among seven strains of Leuconostoc spp. isolated from Argentine raw milk, Leuconostoc Lactis DSM 20202T (T = type strain) and DSM 20198, Leuconostoc mesenteroides subsp. mesenteroides NCDO 523T, Leuconostoc mesenteroides subsp. dextranicum NCDO 529T, and Leuconostoc paramesenteroides DSM 20288T were determined by performing a numerical analysis of total soluble cell protein patterns and DNA-DNA hybridization data. The Argentine raw milk strains formed a tight genotypic cluster at an r value of ≥0.85 and exhibited low levels of DNA homology with the other species included in this study. These strains represent a new species within the group of Leuconostocs isolated from milk or dairy products. The name Leuconostoc argentinum sp. nov. is proposed; the type strain is strain LL76.

  • Identification of Leuconostoc Strains Isolated from Argentine Raw Milk
    Systematic and Applied Microbiology, 1992
    Co-Authors: L. Fantuzzi, Leon M. T. Dicks, M. Du Toit, R. Reniero, Vittorio Bottazzi, Franco Dellaglio
    Abstract:

    Summary The genotypic relatedness among eight strains of Leuconostoc spp. isolated from Argentine raw milk, and reference strains of Leuconostoc Lactis DSM 20202 T , Leuconostoc mesenteroides subsp. mesenteroides NCDO 523 T , Leuconostoc mesenteroides subsp. dextranicum NCDO 529 T , Leuconostoc paramesenteroides DSM 20288 T and Leuconostoc pseudomesenteroides NCDO 768 was determinated using numerical analysis of total soluble cell protein patterns, D(-)-lactate dehydrogenase (LDH) electrophoretic profiles, and DNA-DNA hybridizations. On the basis of these results, eight strains isolated from Argentine raw milk are allotted to the taxa Leuconostoc mesenteroides subsp. mesenteroides and Leuconostoc mesenteroides subsp. dextranicum . Genomic DNA of two of the eight strains was extracted and digested with 11 restriction endonucleases. DNA cleavage patterns were identical even when the plasmid profiles were different. Analysis of plasmid profiles and chromosomal DNA cleavage patterns were also performed for two other strains previously classified phenotypically as Leuconostoc Lactis .