• Journal of Microbiology and Biotechnology
• /
• 제16권4호
• /
• pp.569-575
• /
• 2006

The 530 stem-loop is a 46 nucleotide stem-loop structure found in all small-subunit ribosomal RNAs. Phylogenetic and mutational studies by others suggest the requirement for Watson-Crick interactions between the nucleotides 505-507 and 524-526 (530 pseudoknot), which are highly conserved. To examine the nature and functional significance of these interactions, a random mutagenesis experiment was conducted in which the nucleotides in the proposed pseudoknot were simultaneously mutated and functional mutants were selected and analyzed. Genetic analysis revealed that the particular nucleotide present at each position except 524 was not exclusively critical to the selection of functional mutants. It also indicated that basepairing interactions between the positions 505-507 and 524-526 were required for ribosomal function, and much weaker base-pairing interactions than those of the wild-type also allowed high ribosomal function. Our results support the hypothesis that the 530 pseudoknot structure may undergo a 'conformational switch' between folded and unfolded states during certain stages of the protein synthesis process by interacting with other ligands present in its environment.

• Journal of Microbiology and Biotechnology
• /
• 제25권8호
• /
• pp.1321-1323
• /
• 2015

Lactic acid bacteria (LAB) are microorganisms that are believed to provide health benefits. Here, we isolated LAB from Indian fermented foods, such as traditional Yogurt and Dosa. LAB from Yogurt most significantly induced TNF-α and IL-1β production, whereas LAB from Dosa induced mild cytokine production. After 16S rRNA gene sequencing and phylogenetic analysis, a Yogurt-borne lactic acid bacterium was identified and classified as Lactobacillus delbrueckii subsp. bulgaricus, and it was renamed L. delbrueckii K552 for the further studies. Our data suggest that the newly isolated L. delbrueckii can be used for the treatment of immune deficiency disorders.

• Journal of Microbiology
• /
• 제37권4호
• /
• pp.193-199
• /
• 1999

Fifty-eight strains showing different colony morphological characteristics on various media were isolated from marine coral (Plexauridae sp.) and ambient seawater near Mun-Sum, Cheju-Island in 1998. Bacterial diversity was studies by phylogenetic analysis of the partial 16S rRNA gene sequences. All isolates representing the bacterial domain included affiliates of the high G+C (59%) and los G+C (3%) subdivision of Gram positive bacteria, and the alpha (33%) and gamma (5%) subdivision of the Proteobacteria. The 16S rDNA sequence similarity of the isolates was in the 88.3 to 100% range (average, 95.6%) to reported sequence data. In the comparison of the isolates from marine coarl and ambient seawater, more diverse groups belonging to ${\alpha}$-Proteobacteria were preferentially obtained from seawater.

• Journal of Species Research
• /
• 제8권4호
• /
• pp.351-364
• /
• 2019

Here we describe indigenous prokaryotic species in Korea, a total of 42 bacterial strains affiliated to the class Alphaproteobacteria isolated from various environmental samples: fermented vinegar, sea water, beach sand, fresh water, salt flats, moss, algae, activated sludge, and soil. From the high 16S rRNA gene sequence similarity (>98.7%) and formation of a robust phylogenetic clade with the closest species, it was determined that each strain belonged to predefined bacterial species. There is no official report that these 42 species included in Alphaproteobacteria in Korea: 15 species of 6 genera in the order Rhodospirillales, 12 species of 10 genera in the order Rhizobiales, 10 species of 8 genera in the order Rhodobacterales, 4 species of 4 genera in the order Sphingomonadales and 1 species of 1 genus in the order Caulobacterales. Gram reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and strain IDs are also described in the species description section.

• Journal of Species Research
• /
• 제8권4호
• /
• pp.337-350
• /
• 2019

In an investigation of indigenous prokaryotic species in Korea, a total of 35 bacterial strains assigned to the phylum Firmicutes were isolated from diverse habitats including natural and artificial environments. Based on their high 16S rRNA gene sequence similarity (>98.7%) and formation of robust phylogenetic clades with species of validly published names, the isolates were identified as 35 species belonging to the orders Bacillales (the family Bacillaceae, Paenibacillaceae, Planococcaceae, and Staphylococcaceae) and Lactobacillales (Aerococcaceae, Enterococcaceae, Lactobacillaceae, Leuconostocaceae, and Streptococcaceae). Since these 35 species in Korean environments has not been reported in any official report, we identified them as unrecorded bacterial species and investigated them taxonomically. The newly found unrecorded species belong to 20 species in the order Bacillales and 15 species in the order Lactobacillales. The morphological, cultural, physiological, and biochemical properties of the isolates were examined and the descriptive information of the 35 previously unrecorded species is provided here.

• ALGAE
• /
• 제36권3호
• /
• pp.155-163
• /
• 2021

The crustose brown algal genus Endoplura has been known as a monotypic genus characterized by its intercalary plurangial reproductive structures composed of 2-4 separate parallel filaments terminated by 2-5 sterile cells and by containing several to many chloroplasts per cell. In this study, Endoplura jejuensis sp. nov. and E. koreana sp. nov. from Korea are newly described based on molecular and morphological analyses. Our phylogenetic analyses of the rbcL gene reveal that E. jejuensis sp. nov. and E. koreana sp. nov. are placed in the same clade with "E. aurea" from Japan with a strong bootstrap supporting value. E. jejuensis is characterized by small and light to dark brown crustose thalli of less than 1 cm diameter, tufts of hairs arising from the basal disc, plurangia composed mostly of two separate parallel reproductive filaments terminated by 2-4 sterile cells, and sessile unangia each with a single paraphysis. E. koreana is distinguished by olive or yellowish-brown crustose thalli of up to 3 cm diameter, tufts of hairs arising from the basal disc, and apical parts of erect filaments, plurangia with 2-5 separate reproductive filaments terminated by 2-8 sterile cells, and sessile unangia with 1-2 paraphyses. Our studies also show that "E. aurea" specimens from Japan may be recognized to be a different species from other Endoplura species.

• Journal of Forest and Environmental Science
• /
• 제35권2호
• /
• pp.90-101
• /
• 2019

Biodiversity refers to the total number and variation among species of flora and fauna of an area. Due to tremendous biotic especially anthropogenic pressure these natural resources are being vanishing. In present study genetic diversity among accessions of Thamnocalamus spathiflorus was evaluated. A total of 51 vegetative characters and 42 primers (10-mer) were screened. Out of 42 screened primers, 28 polymorphic primers were selected for further analysis. A total of 263 bands were recorded as polymorphic whereas 48 bands were monomorphic. The resolving power (Rp) of 28 Randomly Amplified Polymorphic DNA (RAPD) primers ranged from 4.6 (OPE08) to 17.6 (OPA11). The polymorphic information content (PIC) value ranged from 0.21 (OPAH09) to 0.44 (OPG02). The result revealed high degree of genetic relatedness (56 to 80%). Cluster analysis revealed two major clusters both for morphology as well as RAPD. Unlike morphological characterization, the accession (D5) from Bahli, Rampur, Shimla (H.P.) was clustered separately from the others in RAPD cluster analysis. Accessions with closed locality grouped together through RAPD marker system however analogy was recorded for morphological traits. The study conducted reflects the utility of RAPD technique for species identification and phylogenetic studies in bamboo for conducting bamboo breeding program.

• Journal of Species Research
• /
• 제10권3호
• /
• pp.201-216
• /
• 2021

During an investigation of indigenous prokaryotic species in the Republic of Korea, a total of 38 bacterial strains belonging to the class Gammaproteobacteria were isolated from diverse environments. Samples were collected from soil, seawater, sand, sedimentary soil, rabbit feces, rat intestines, marine wetland, and tidal flats. The strains were identified to the species level using the high 16S rRNA gene sequences and showed high similarity (>98.7%) with the closest bacterial species and formed a robust clade in the neighbor-joining phylogenetic tree; it was determined that each strain belonged to independent, predefined bacteria species within the class Gammaproteobacteria. The 38 strains of Gammaproteobacteria analyzed in this study have not been reported in the Republic of Korea. Therefore, this study describes 20 genera of 13 families in 8 orders: Aeromonadales, Alteromonadales, Cellvibrionales, Enterobacterales, Lysobacterales, Oceanospirillales, Pseudomonadales, and Vibrionales. For each species, we describe Gram reaction, strain ID, isolation source, colony and cell morphology, cultural, physiological, and basic biochemical characteristics.

• Journal of Species Research
• /
• 제10권1호
• /
• pp.12-22
• /
• 2021

During a comprehensive investigation of indigenous prokaryotic species in Korea, 25 and 10 bacterial strains assigned to the classes Alphaproteobacteria and Betaproteobacteria, respectively, were isolated from diverse environmental habitats, including soil, mud, tidal field, sea water, sand, rusted iron, and leaf. Based on their high 16S rRNA gene sequence similarities (>98.7%) and the formation of robust phylogenetic clades with type species, each strain was assigned to an independent and predefined bacterial species. Since there were no published or official reports regarding these 35 isolates in Korea, they - 25 species of 14 families in the 5 orders of Alphaproteobacteria and 10 species of 3 families in the two orders of Betaproteobacteria - have been reported as unrecorded species in Korea. In addition, Gram reaction, colony and cell morphology, basic biochemical characteristic, isolation source, and strain ID of each species are also described in the species description sections.

• Journal of Veterinary Science
• /
• 제19권6호
• /
• pp.798-807
• /
• 2018

Several studies have reported the effect of absorption of procyanidins and their contribution to the small intestine. However, differences between dietary interventions of procyanidins and interventions via antibiotic feeding in pigs are rarely reported. Following 16S rRNA gene Illumina MiSeq sequencing, we observed that both procyanidin administration for 2 months (procyanidin-1 group) and continuous antibiotic feeding for 1 month followed by procyanidin for 1 month (procyanidin-2 group) increased the number of operational taxonomic units, as well as the Chao 1 and ACE indices, compared to those in pigs undergoing antibiotic administration for 2 months (antibiotic group). The genera Fibrobacter and Spirochaete were more abundant in the antibiotic group than in the procyanidin-1 and procyanidin-2 groups. Principal component analysis revealed clear separations among the three groups. Additionally, using the online Molecular Ecological Network Analyses pipeline, three co-occurrence networks were constructed; Lactobacillus was in a co-occurrence relationship with Trichococcus and Desulfovibrio and a co-exclusion relationship with Bacillus and Spharerochaeta. Furthermore, metabolic function analysis by phylogenetic investigation of communities by reconstruction of unobserved states demonstrated modulation of pathways involved in the metabolism of carbohydrates, amino acids, energy, and nucleotides. These data suggest that procyanidin influences the gut microbiota and the intestinal metabolic function to produce beneficial effects on metabolic homeostasis.