Publications by authors named "Dae Gyu Choi"

The novel strain CBA3628 was isolated from kimchi, a Korean fermented vegetable. CBA3628 is a cocci-shaped, Gram-stain-positive, catalase- and oxidase-negative and facultatively anaerobic bacterium. The results of phylogenetic analysis based on 16S rRNA gene sequencing indicated that CBA3628 represented a member of the genus of the family .

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Article Synopsis
  • Three new Gram-negative, aerobic bacteria were isolated from marine algae in South Korea, named G8-12, SS1-5, and BS5-3, each showing distinct growth conditions and characteristics.
  • These strains contained specific lipids and fatty acids and had G+C content percentages of 57.0%, 58.3%, and 56.4%, which helped confirm their unique identities.
  • Phylogenetic analysis revealed these strains belong to different species within the same genus, leading to their proposal as three novel species with designated names.
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Fermentative features of doenjang-meju, a traditional Korean soybean brick, were investigated over 45 days via genome-centered metatranscriptomics. The pH value rapidly decreased within 10 days and successively increased after 20 days, along with an initial bacterial growth, including lactic acid bacteria, and subsequent fungal growth, suggesting their association. Polysaccharides and lipids underwent degradation, and amino acids, free sugars, and organic acids increased during the early stage.

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A Gram-stain-negative, facultative aerobic, catalase- and oxidase-positive, non-motile, non-flagellated, and coccus-shaped bacterium, strain J2-16, isolated from a marine green alga, was characterized taxonomically. Strain J2-16 grew at 20-40 °C (optimum, 30 °C), pH 6.0-10.

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Two Gram-stain-negative, facultatively aerobic, and motile rod bacteria, designated as strains KJ51-3 and 15G1-11, were isolated from marine algae collected in the Republic of Korea. Both strains exhibited catalase- and oxidase-positive activities. Optimum growth conditions for strain KJ51-3 were observed at 30 °C and pH 6.

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Two Gram-stain-negative, strictly aerobic rods, designated as RMAR6-6 and KMA01, exhibiting catalase- and oxidase-positive activities, were isolated from marine red algae in the Republic of Korea. Cells of strain RMAR6-6 exhibited flagellar motility, while those of strain KMA01 were non-motile. Strain RMAR6-6 exhibited optimal growth at 30-35°C and pH 7.

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Aspergillus flavus and Aspergillus oryzae are closely related fungal species with contrasting roles in food safety and fermentation. To comprehensively investigate their phylogenetic, genomic, and metabolic characteristics, we conducted an extensive comparative pangenome analysis using complete, dereplicated genome sets for both species. Phylogenetic analyses, employing both the entirety of the identified single-copy orthologous genes and six housekeeping genes commonly used for fungal classification, did not reveal clear differentiation between A.

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Background: Enterococcus faecium and E. lactis are phylogenetically closely related lactic acid bacteria that are ubiquitous in nature and are known to be beneficial or pathogenic. Despite their considerable industrial and clinical importance, comprehensive studies on their evolutionary relationships and genomic, metabolic, and pathogenic traits are still lacking.

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The metabolic characteristics of Leuconostoc mesenteroides subsp. mesenteroides J18, which is mainly responsible for kimchi fermentation, on various carbon sources were investigated through carbon utilization, metabolite, and transcriptome analyses at different culture conditions (10 and 30 °C with/without 2.5% NaCl).

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A Gram-stain-positive, spore-forming and facultative aerobic bacterium, designated C11, was isolated from mountain soil collected in the Republic of Korea. The cells were motile rods with peritrichous flagella, and positive for catalase and oxidase activities. Strain C11 grew at 15-45 °C (optimum, 30-37 °C) and pH 6.

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A strictly aerobic Gram-negative bacterium, designated R8, isolated from garden soil in South Korea was subjected to a taxonomic study. The cells were non-spore-forming, oxidase-positive and catalase-negative, and non-motile rods (without flagella). Growth was observed between 10 °C and 40 °C (optimum, 30 °C) and between pH 6.

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