No abstract

Kimchi is often stored for a long period of time for a diet during the winter season because it is an essential side dish for Korean meals. In this study pH, abundance of bacteria and yeasts, bacterial communities, and metabolites were monitored periodically to investigate the fermentation process of kimchi for 120 d. Bacterial abundance increased quickly with a pH decrease after an initial pH increase during the early fermentation period. After 20 d, pH values became relatively stable and free sugars were maintained at relatively constant levels, indicating that kimchi fermentation by lactic acid bacteria (LAB) was almost completed. After that time, a decrease in bacterial abundance and a growth in Saccharomyces occurred concurrently with increased free sugar consumption and production of glycerol and ethanol. Finally, after 100 d, the growth of Candida was observed. Community analysis using pyrosequencing revealed that diverse LAB including Leuconostoc citreum, Leuconostoc holzapfelii, Lactococcus lactis, and Weissella soli were present during the early fermentation period, but the LAB community was quickly replaced with Lactobacillus sakei, Leuconostoc gasicomitatum, and Weissella koreensis as the fermentation progressed. Metabolite analysis using (1) H-NMR showed that organic acids (lactate, acetate, and succinate) as well as bioactive substances (mannitol and gamma-aminobutyric acid (GABA)) were produced during the kimchi fermentation, and Leuconostoc strains and Lactobacillus sakei were identified as the producers of mannitol and GABA, respectively.

No abstract

Aestuariibaculum suncheonense gen. nov., sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from a tidal flat and emended descriptions of the genera Gaetbulibacter and Tamlana T was observed at 5-40 6C (optimum, 25-30 6C), at pH 6.0-8.5 (optimum, pH 7.0) and in the presence of 1-8 % (w/v) NaCl (optimum, 1-2 %). The major cellular fatty acids were iso-C 15 : 0 , summed feature 3 (comprising C 16 : 1 v7c and/or C 16 : 1 v6c and/or iso-C 15 : 0 2-OH), iso-C 17 : 0 3-OH, iso-C 15 : 1 G and anteiso-C 15 : 0. The polar lipid content consisted of phosphatidylethanolamine and unidentified amino lipids and lipids. The G+C content of the genomic DNA was 46.4 mol% and the only respiratory quinone detected was menaquinone-6 (MK-6). Phylogenetic inference based on 16S rRNA gene sequences showed that strain SC17T formed a distinct phyletic lineage within the family Flavobacteriaceae and was most closely related to members of the genera Gaetbulibacter and Tamlana with 95.0-95.8 % sequence similarity. On the basis of phenotypic and molecular features, strain SC17 T represents a novel genus of the family Flavobacteriaceae, for which the name Aestuariibaculum suncheonense gen. nov., sp. nov. is proposed. The type strain is SC17 T (5KACC 16186 T 5JCM 17789 T ). Emended descriptions of the genera Gaetbulibacter and Tamlana are also proposed.The families Flavobacteriaceae, Bacteroidaceae, Cryomorphaceae, Cytophagaceae, Chitinophagaceae and Sphingobacteriaceae consist of very diverse taxa and they are affiliated with the different classes of the phylum Bacteroidetes: the class Flavobacteriia (families Flavobacteriaceae and Cryomorphaceae), the class Bacteroidia (family Bacteroidaceae), the class Cytophagia (family Cytophagaceae) and the class Sphingobacteriia (families Chitinophagaceae and Sphingobacteriaceae) (Ludwig et al., 2010). The family Flavobacteriaceae contains Gram-stain-negative, rod-shaped, chemoheterotrophic bacteria that are non-motile or motile by gliding and contain menaquinone-6 (MK-6) as the major isoprenoid quinone (Bernardet et al., 2002;Bowman & Nichols, 2005;Bernardet & Nakagawa, 2006;Bernardet, 2011). Currently, the family Flavobacteriaceae consists of more than 90 genera with validly published names. Sea tidal flats are broad, plain marshes with low-gradients, or muddy coast areas that experience exposure and flooding by seawater between low and high tides. The west and south-west coast of the Korean peninsula largely consists of sea tidal flats, called getbol, that contain a wealth of valuable biological resources such as micro-organisms and marine animals. Recently, numerous microbial species have been isolated from sea tidal flats. Therefore, efforts have been made in our laboratory to isolate and characterize marine bacteria from sea tidal flats (Jin et al., 2011a, b;Jung et al., 2011;Lee et al., 2011;Park et al., 2011).In the course of this study, a novel yellow-pigmented, Gramstaining-negative, rod-shaped bacterium was isolated. Here, we describe its taxonomic characterization and pro...

Two moderately halophilic, facultatively aerobic, motile bacteria with flagella, designated strains 10-C-3(T) and 30-C-3, were isolated from jeotgal, a traditional Korean fermented seafood. Cells of the strains were observed to be ovoid-rods showing catalase- and oxidase-positive reactions and production of creamy-pink pigments. Growth of strain 10-C-3(T) was observed at 15-35 °C (optimum, 25-30 °C), at pH 5.5-9.0 (optimum, pH 7.0-7.5), and in the presence of 3-15 % (w/v) salts (optimum: 5-10 %). The two strains were found to contain C(18:1) ω7c, C(16:0), summed feature 3 (as defined by the MIDI system, comprising C(16:1) ω7c and/or C(16:1) ω6c), and C(12:0) 3-OH as the major cellular fatty acids. The G+C contents of the genomic DNA of strains 10-C-3(T) and 30-C-3 were determined to be 63.2 and 63.1 mol%, respectively and the respiratory quinone detected was ubiquinone 9 (Q-9) only. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strains 10-C-3(T)and 30-C-3 formed a distinct phyletic lineage within the genus Halomonas and are most closely related to Halomonas fontilapidosi 5CR(T) with 95.2 % of 16S rRNA sequence similarity. Strains 10-C-3(T)and 30-C-3 shared 99.2 % of 16S rRNA gene sequence similarity and their DNA-DNA relatedness value was 96.6 ± 0.9 %. On the basis of phenotypic, chemotaxonomic and molecular features, strains 10-C-3(T)and 30-C-3 represent a novel species of the genus Halomonas, for which the name Halomonas cibimaris sp. nov. is proposed. The type strain is 10-C-3(T) (= KACC 14932(T) = JCM 16914(T)).