• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1509-1518
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• 2013

An agar-degrading bacterium, designated as strain $G7^T$, was isolated from a coastal seawater sample from Gaya Island (Gayado in Korean), Republic of Korea. The isolated strain $G7^T$ is gram-negative, rod shaped, aerobic, non-motile, and non-pigmented. A similarity search based on its 16S rRNA gene sequence revealed that it shares 95.5%, 90.6%, and 90.0% similarity with the 16S rRNA gene sequences of Catenovulum agarivorans $YM01^T$, Algicola sagamiensis, and Bowmanella pacifica W3-$3A^T$, respectively. Phylogenetic analyses demonstrated that strain $G7^T$ formed a distinct monophyletic clade closely related to species of the family Alteromonadaceae in the Alteromonas-like Gammaproteobacteria. The G+C content of strain $G7^T$ was 41.12 mol%. The DNA-DNA hybridization value between strain $G7^T$ and the phylogenetically closest strain $YM01^T$ was 19.63%. The genomes of $G7^T$ and $YM01^T$ had an average ANIb value of 70.00%. The predominant isoprenoid quinone of this particular strain was ubiquinone-8, whereas that of C. agarivorans $YM01^T$ was menaquinone-7. The major fatty acids of strain $G7^T$ were Iso-$C_{15:0}$ (41.47%), Anteiso-$C_{15:0}$ (22.99%), and $C_{16:1}{\omega}7c/iso-C_{15:0}2-OH$ (8.85%), which were quite different from those of $YM01^T$. Comparison of the phenotypic characteristics related to carbon utilization, enzyme production, and susceptibility to antibiotics also demonstrated that strain $G7^T$ is distinct from C. agarivorans $YM01^T$. Based on its phenotypic, chemotaxonomic, and phylogenetic distinctiveness, strain $G7^T$ was considered a novel genus and species in the Gammaproteobacteria, for which the name Gayadomonas joobiniege gen. nov. sp. nov. (ATCC BAA-2321 = $DSM25250^T=KCTC23721^T$) is proposed.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.276-283
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• 2004

Screening was performed to isolate cellulose-producing microorganisms from the Korean traditional fermented persimmon vinegar. The resulting strain, KJ $145^{T}$, was then taxonomically investigated by phenotypic characterization, particularly chemotaxonomic, and by phylogenetic inference based on a 16S rDNA sequence analysis including other related taxa. Strain KJ $145^{T}$ was found to grow rapidly and form pale white colonies with smooth to rough surfaces on a GYC agar. Strain KJ $145^T$ also produced acetate from ethanol, and was tolerable to 10% ethanol in SM medium. In a static culture, a thick cellulose pellicle was produced, and in GYC broth, the strain grew at temperatures ranging from 28 to $40^\circ{C}$ with an optimum pH of 4.0. The genomic DNA G+C content of strain KJ $145^T$ was 61.9 mol%, and the predominant ubiquinone was Q 10 as the major quinone and Q9 as the minor quinone. The major cellular fatty acids were $C_{16:0}$ and the sum in feature 7 ($C_{18:1}$ w9c, w12t and/or w7c). A 16S rRNA-targeted oligonucleotide probe specific for strain KJ $145^T$was constructed, and the phylogenetic position of the new species was derived from a 16S rDNA-based tree. When comparing the 16S rDNA nucleotide sequences, strain KJ $145^T$ was found to be most closely related to G. hansenii LMG $1527^T$ (99.2%), although KJ $145^T$ was still distinct from G. hansenii LMG $l527^T$ and G. xylinus LMG $1515^T$ in certain phenotypic characteristics. Therefore, on the basis of 16S rDNA sequences and taxonomic characteristics, it is proposed that strain KJ $145^T$ should be placed in the genus Gluconacetobacter as a new species, Gluconacetobacter persimmonis sp. nov., under the type-strain KJ $145^T$ (=KCTC =$10175BP^T$=KCCM=$10354^T$).

• The Plant Pathology Journal
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• v.19 no.1
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• pp.13-18
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• 2003

From 1996 to 1999, potato-growing areas in Korea were surveyed for identification and distribution of potato scab pathogens. Potato scab was widely distributed in the mass cultivation areas, especially in Jriu island, southern areas of Chonnam and Gyounggi provinces, and the alpine area of Gangwon province. Jeju island was the most affected area by this disease. A total of 55 Streptomyces strains were isolated from potato scab lesions, among which 40 strains were pathogenic on progeny tubers. Among the pathogenic strain, 21 strains were identified as previously described S. scabies, 7 Strains as S. turgidiscabies, and 5 Strains as S. acidiscabies, while 7 strains were observed as having distinct phenotypic properties. These strains were classified into six distinct clusters based on phenotypic characteristics and selected representative strains for each cluster. S. scabies (S33) had grey spores in a spiral chain. Mean-while, S. turgidiscabies (S27) had grey spores, S. acidiscabies (S71) had white spores, S. luridiscabiei (S63) had yellow-white spores, S. puniciscabiei (S77) had purple-red spores, and S. niveiscabiei (S78) had thin and compact white spores, all in a rectiflexuous chain. Pathogenicity was determined by the production of thaxtomin A and homologs of necl and ORFtnp genes. In TLC, representative strains S27, S71, S63, S77, and S78 produced a yellow band that co-migrated with the authentic thaxtomin A. However, thaxtomin A was not detected in chloroform extracts from oatmeal broth culture and Slice tuber tissue of S. luridiscabiei (S63) and S. puniciscabiei (S77) by HPLC analysis. In addition, no homologs of necl and ORFtnp genes in S. acidiscabies (S71), S. luridiscabiei (S63), S. puniciscabiei (S77), and S. niveiscabiei (S78) were detected by PCR and Southern hybridization analysis.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.478-490
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• 2021

We aimed to generate basic breeding data for melon (Cucumis melo L.). A total of 219 melon accessions conserved at the National Agrobiodiversity Center (NAC) in Rural Development Administration (RDA) were used in this study, of which 72 (33%) were collected from India. The majority of accessions showed orange (42%) and white (36%) flesh color. In addition to phenotypic evaluations, the accessions were genotyped using a molecular marker for the carotenoid biosynthesis gene CmOr. DNA fragments of the expected size were amplified in 205 out of 219 accessions. Digestion of the PCR products with HinfI restriction endonuclease showed 100% concordance between phenotype and genotype in green-fleshed accessions, but 98%, 97%, and 80% concordance in orange-, white-, and creamy-fleshed accessions, respectively. Sequence analysis revealed single nucleotide changes in the three positions of SNP1, SNP2 and SNP1int in the CmOr gene among accessions. These newly found alleles suggest that there are multiple mechanisms in determining fruit flesh color in melon. Also, the phenotype data of diverse accessions obtained in this study will be a valuable source for melon breeding.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.449-456
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• 2008

Phenotypic screening for bile salt hydrolase (BSH) activity was performed on Lactobacillus acidophilus PF01 isolated from piglet feces. A gene encoding BSH was identified and cloned from the genomic library of L. acidophilus PF01. The bsh gene and surrounding regions were characterized by nucleotide sequence analysis and were found to contain a single open reading frame (ORF) of 951 nucleotides encoding a 316 amino acid protein. The potential bsh promoter region was located upstream of the start codon. The protein deduced from the complete ORF had high similarity with other BSHs, and four amino acid motifs located around the active site, FGRNXD, AGLNF, VLTNXP, and GXGXGXXGXPGD, were highly conserved. The bsh gene was cloned into the pET21b expression vector and expressed in Escherichia coli BLR(DE3) by induction with 0.1mM of isopropylthiogalactopyranoside. The BSH enzyme was purified with apparent homogeneity using a $Ni^{2+}$-NTA agarose column and characterized. The overexpressed recombinant BSH enzyme of L. acidophilus PF01 exhibited hydrolase activity against tauroconjugated bile salts, but not glycoconjugated bile salts. It showed the highest activity against taurocholic acid. The maximum BSH activity occurred at approximately $40^{\circ}C$. The enzyme maintained approximately 70% of its maximum activity even at $60^{\circ}C$, whereas its activity rapidly decreased at below $37^{\circ}C$. The optimum pH was 6, and BSH activity was rapidly inactivated below pH 5 and above pH 7.

• The Plant Pathology Journal
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• v.23 no.2
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• pp.51-56
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• 2007

A plant pathogenic fungus, Gibberella zeae (anamorph: Fusarium graminearum), not only generates economic losses by causing disease on cereal grains, but also leads to severe toxicosis in human and animals through the production of mycotoxins in infected plants. Here, we characterized a histidine auxotrophic mutant of G. zeae, designated Z43R1092, which was generated using a restriction enzyme-mediated integration (REMI) procedure. The mutant exhibited pleiotropic phenotypic changes, including a reduction in mycelial growth and virulence and loss of sexual reproduction. Outcrossing analysis confirmed that the histidine auxotrophy is linked to the insertional vector in Z43R1092. Molecular analysis showed that the histidine requirement of Z43R1092 is caused by a disruption of an open reading frame, designated GzHIS7. The deduced product of GzHIS7 encodes a putative enzyme with an N-terminal glutamine amidotransferase and a C-terminal cyclase domain, similar to the Saccharomyces cerevisiae HIS7 required for histidine biosynthesis. The subsequent gene deletion and complementation analyses confirmed the functions of GzHIS7 in G. zeae. This is the first report of the molecular characterization of histidine auxotrophy in G. zeae, and our results demonstrate that correct histidine biosynthesis is essential for virulence, as well as sexual development, in G. zeae. In addition, our results could provide a G. zeae histidine auxotroph as a recipient strain for genetic transformation using this new selectable marker.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.18 no.2
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• pp.138-143
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• 2015

Glycogen storage disease type IX (GSD IX) is caused by a defect in phosphorylase b kinase (PhK) that results from mutations in the PHKA2, PHKB, and PHKG2 genes. Patients usually manifest recurrent ketotic hypoglycemia with growth delay, but some may present simple hepatomegaly. Although GSD IX is one of the most common causes of GSDs, its biochemical and genetic diagnosis has been problematic due to its rarity, phenotypic overlap with other types of GSDs, and genetic heterogeneities. In our report, a 22-month-old boy with GSD IX is described. No other manifestations were evident except for hepatomegaly. His growth and development also have been proceeding normally. Diagnosed was made by histologic examination, an enzyme assay, and genetic testing with known c.3210_3212del (p.Arg1070del) mutation in PHKA2 gene.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.828-834
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• 2010

An ethanol-producing yeast strain, CHFY0201, was isolated from soil in South Korea using an enrichment technique in a yeast peptone dextrose medium supplemented with 5% (w/v) ethanol at $30^{\circ}C$. The phenotypic and physiological characteristics, as well as molecular phylogenetic analysis based on the D1/D2 domains of the large subunit (26S) rDNA gene and the internally transcribed spacer (ITS) 1+2 regions, suggested that the CHFY0201 was a novel strain of Schizosaccharomyces pombe. During shaking flask cultivation, the highest ethanol productivity and theoretical yield of S. pombe CHFY0201 in YPD media containing 9.5% total sugars were $0.59{\pm}0.01$ g/l/h and $88.4{\pm}0.91%$, respectively. Simultaneous saccharification and fermentation for ethanol production was carried out using liquefied cassava (Manihot esculenta) powder in a 5-l lab-scale jar fermenter at $32^{\circ}C$ for 66 h with an agitation speed of 120 rpm. Under these conditions, S. pombe CHFY0201 yielded a final ethanol concentration of $72.1{\pm}0.27$ g/l and a theoretical yield of $82.7{\pm}1.52%$ at a maximum ethanol productivity of $1.16{\pm}0.07$ g/l/h. These results suggest that S. pombe CHFY0201 is a potential producer for industrial bioethanol production.

• Journal of Sericultural and Entomological Science
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• v.40 no.1
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• pp.43-51
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• 1998

Studies were carried out to investigate phenotypic expression, mortality and biochemical analysis of haemolymph proteins of nm-d, nm-f, nm-k and nmn bib-molting mutants of the silkworm, Bombyx mori. The non-molting mutants characters were expressed in the homozygote of each mutant genes. All strains of non-molting mutants were similar with each other in physiological characteristics, but the expression varied with each strains. The larvae of nm-d, nm-i and nmn died between day 5 and day 9 after hatching without the first molt. The nm-f and nm-k mutants died between day 5 and day 16 with a slight increase of body weight and, more than 90% of the mutants larvae died before the first molt and a few of them survived to the 2nd and the 3rd instar and died. The haemolymph protein components of nm-d, nm-i, and nmn were rapidly reduced, and on the other hand those of nm-f and nm-k consistently until they died. And there were no distinguishable difference in haemolymph components of non-molting mutants, as compared to those normals.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.96-103
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• 2007

Plant growth-promoting rhizobacteria (PGPR) have the potential to be used as microbial inoculants to reduce disease incidence and severity and to increase crop yield. Some of the PGPR have been reported to be able to enter plant tissues and establish endophytic populations. Here, we demonstrated an approach to screen bacterial endophytes that have the capacity to promote the growth of pepper seedlings and protect pepper plants against a bacterial pathogen. Initially, out of 150 bacterial isolates collected from healthy stems of peppers cultivated in the Chungcheong and Gyeongsang provinces of Korea, 23 putative endophytic isolates that were considered to be predominating and representative of each pepper sample were selected. By phenotypic characterization and partial 16S rDNA sequence analysis, the isolates were identified as species of Ochrobacterium, Pantoea, Pseudomonas, Sphingomonas, Janthinobacterium, Ralstonia, Arthrobacter, Clavibacter, Sporosarcina, Acidovorax, and Brevundimonas. Among them, two isolates, PS4 and PS27, were selected because they showed consistent colonizing capacity in pepper stems at the levels of $10^6-10^7CFU/g$ tissue, and were found to be most closely related to Pseudomonas rhodesiae and Pantoea ananatis, respectively, by additional analyses of their entire 16S rDNA sequences. Drenching application of the two strains on the pepper seedlings promoted significant growth of peppers, enhancing their root fresh weight by 73.9% and 41.5%, respectively. The two strains also elicited induced systemic resistance of plants against Xanthomonas axonopodis pv. vesicatoria.