• Korean Journal of Microbiology
• /
• v.49 no.3
• /
• pp.228-236
• /
• 2013

Campylobacter jejuni is one of important food-borne pathogens causing human gastroenteritis. We isolated 42 strains of C. jejuni from diarrhea patients and 4 food-poisoning outbreaks in 2010, Gyeonggi-do. In this study, 42 strains were tested for genetic characteristics, the serotype distribution and antimicrobial resistant rate. The presence of hipO (100%), cdtB (100%), and mutated gyrA (95.2%) genes was detected in C. jejuni by polymerase chain reaction (PCR). Detection of mutated gyrA gene correlated with ciprofloxacin resistance. Forty isolates had mutated gyrA gene and were actually resistant to ciprofloxacin. Furthermore, comparing the gyrA DNA sequence data, ciprofloxacin-resistant isolates had a mutation of the DNA sequence from ACA (threonine) to ATA (isoleucine). But 41 strains (97.6%) of patient isolates were susceptible to erythromycin and azithromycin. A total of 35.7% among 42 C. jejuni isolates were identified into 4 different serotypes. The serotype distribution of C. jejuni strains were shown to be HS2(B), HS3(C), HS4(D), HS19(O). To investigate the genotypes of C. jejuni isolated in Gyeonggi province, repetitive sequence polymerase chain reaction (rep-PCR) analysis and SmaI-digested pulsed-filed gel electrophoresis (PFGE) profile analysis were performed. From the PFGE analysis of 42 C. jejuni strains, 12 clusters of PFGE profile were obtained. On the other hand, 11 clusters of rep-PCR profile were obtained from 42 strains of C. jejuni.

• Journal of Life Science
• /
• v.31 no.3
• /
• pp.356-365
• /
• 2021

Recently, we sequenced the entire genome of a freshwater agar-degrading bacterium Cellvibrio sp. KY-GH-1 (KCTC13629BP) to explore genetic information encoding agarases that hydrolyze agarose into monomers 3,6-anhydro-L-galactose (L-AHG) and D-galactose. The KY-GH-1 strain appeared to possess nine β-agarase genes and two α-neoagarobiose hydrolase (α-NABH) genes in a 77-kb agarase gene cluster. Based on these genetic information, the KY-GH-1 strain-caused agarose degradation into L-AHG and D-galactose was predicted to be initiated by both endolytic GH16 and GH86 β-agarases to generate NAOS (NA4/NA6/NA8), and further processed by exolytic GH50 β-agarases to generate NA2, and then terminated by GH117 α-NABHs which degrade NA2 into L-AHG and D-galactose. More recently, by employing E. coli expression system with pET-30a vector we obtained three recombinant His-tagged GH50 family β-agarases (GH50A, GH50B, and GH50C) derived from Cellvibrio sp. KY-GH-1 to compare their enzymatic properties. GH50A β-agarase turned out to have the highest exolytic β-agarase activity among the three GH50 isozymes, catalyzing efficient NA2 production from the substrate (agarose, NAOS or AOS). Additionally, we determined that GH117A α-NABH, but not GH117B α-NABH, could potently degrade NA2 into L-AHG and D-galactose. Sequentially, we examined the enzymatic characteristics of GH50A β-agarase and GH117A α-NABH, and assessed their efficiency for NA2 production from agarose and for production of L-AHG and D-galactose from NA2, respectively. In this review, we describe the benefits of recombinant GH50A β-agarase and GH117A α-NABH originated from Cellvibrio sp. KY-GH-1, which may be useful for the enzymatic hydrolysis of agarose for mass production of L-AHG and D-galactose.

• Pediatric Infection and Vaccine
• /
• v.12 no.2
• /
• pp.166-177
• /
• 2005

Purpose : The purpose of this study was to examine the molecular epidemiology and genetic variability of adenovirus(Ad) serotypes Ad1, Ad2, and Ad5 over 14 years in Korea. Methods : A total of 382 adenoviral strains isolated from the nasopharyngeal aspirates of children with lower respiratory tract infections in Seoul, Korea from November 1990 to February 2003 were serotyped by neutralization assay with type-specific antisera. Viral DNAs were extracted from infected cell lysates by the modified Hirt procedure. Genome type(GT) was determined by DNA restriction analysis with 12 restriction enzymess(BamHI, BclI, BglI, BglII, BstEII, EcoRI, HindIII, HpaI, SalI, SmaI, XbaI, and XhoI). To evaluate the genetic relatedness, pairwise comigrating restriction fragments(PCRF) analysis was performed. Results : Of 382 strains, 33 strains(9%) were Ad1, 45 strains(12%) were Ad2, and 24 strains(6%) were Ad5. Eighteen GTs(Ad1p1-Ad1p7, Ad1a, Ad1b, Ad1b1-Ad1b3, Ad1c, Ad1d, Ad1e, Ad1e1, Ad1e2, Ad1f) among Ad1, 24(Ad2p1-Ad2p11, Ad2a, Ad2a1-Ad2a6, Ad2b, Ad2c, Ad2d, Ad2e, Ad2e1-Ad2e3) among Ad2, and 10(Ad5p1, Ad5p2, Ad5a, Ad5a1-Ad5a7) among Ad5 strains were identified. One or two strains of the vast majority of GTs were isolated during the study period while a few GTs were identified sporadically with more than 2 strains. It is notable that some GTs such as Ad1p5 and Ad5a1 appeared in cluster during a short period. In analysis of genetic relatedness, the degree of PCRFs(pairwise comigrating restriction fragments) for Ad1 varied from 79 to 99%, for Ad2, 82 to 99%, and for Ad5, 85 to 99%. Conclusion : This study established the comprehensive nomenclature systems of Ad1, Ad2, and Ad5. Diverse GTs identified in this study have crucial implications in the genomic diversity and epidemiological characteristics of Ad1, Ad2, and Ad5.

• Horticultural Science & Technology
• /
• v.30 no.5
• /
• pp.557-567
• /
• 2012

This study was conducted to achieve basal information for the development of tomato cultivars with disease resistances through marker-assisted backcross (MAB). Ten inbred lines with TYLCV, late blight, bacterial wilt, or powdery mildew resistance and four adapted inbred lines with superior horticultural traits were collected, which can be useful as the donor parents and recurrent parents in MAB, respectively. Inbred lines collected were evaluated by molecular markers and bioassay for confirming their disease resistances. To develop DNA markers for selecting recurrent parent genome (background selection) in MAB, a total of 108 simple sequence repeat (SSR) primer sets (nine per chromosome at average) were selected from the tomato reference genetic maps posted on SOL Genomics Network. Genetic similarity and relationships among the inbred lines were assessed using a total of 303 polymorphic SSR markers. Similarity coefficient ranged from 0.33 to 0.80; the highest similarity coefficient (0.80) was found between bacterial wilt-resistant donor lines '10BA333' and '10BA424', and the lowest (0.33) between a late blight resistant-wild species L3708 (S. pimpinelliforium L.) and '10BA424'. UPGMA analysis grouped the inbred lines into three clusters based on the similarity coefficient 0.58. Most of the donor lines of the same resistance were closely related, indicating the possibility that these lines were developed using a common resistance source. Parent combinations (donor parent ${\times}$ recurrent parent) showing appropriate levels of genetic distance and SSR marker polymorphism for MAB were selected based on the dendrogram. These combinations included 'TYR1' ${\times}$ 'RPL1' for TYLCV, '10BA333' or '10BA424' ${\times}$ 'RPL2' for bacterial wilt, and 'KNU12' ${\times}$ 'AV107-4' or 'RPL2' for powdery mildew. For late blight, the wild species resistant line 'L3708' was distantly related to all recurrent parental lines, and a suitable parent combination for MAB was 'L3708' ${\times}$ 'AV107-4', which showed a similarity coefficient of 0.41 and 45 polymorphic SSR markers.

• Korean Journal of Plant Resources
• /
• v.35 no.1
• /
• pp.1-9
• /
• 2022

Perilla is an annual plant in the family Lamiaceae and are widely cultivated in Asian countries. Perilla leaves are important sources of bioactive compounds and are reported to exhibit anti-inflammatory, antibacterial, anti-cancer and antioxidant effects, drawing attention as functional food materials. We examined caffeic acid, rosmarinic acid, total phenol content, and antioxidant activity in the leaves of 18 perilla accessions obtained from the gene bank of the National Agrobiodiversity Center, Jeonju, Korea. The caffeic acid content ranged between 9.86-27.52 mg/g with an average content of 17.75 mg/g while the level of. rosmarinic acid was in the range between 49.14 and 90.30 mg/g with an average content of 61.88 mg/g. The total polyphenol content ranged between 138.39 ㎍ GAE/mg dried extract (DE) and 378.19 ㎍ GAE/mg DE with an average content of 225.93 ㎍ GAE/mg DE. Cluster analysis based on the content of caffeic acid, rosmarinic acid. and antioxidant activity showed that the accessions collections were grouped in two distinct classes. The first group contained six genetic resources with high content of rosmarinic acid, and antioxidant activities respectively. The second group contained 12 genetic resources with high content of caffeic acid. These results could help develop new varieties of nutrient dense perilla resources.

• Journal of Life Science
• /
• v.21 no.10
• /
• pp.1370-1376
• /
• 2011

To study the functional genomic analysis of a crenachaeon Sulfolobus acidocaldarius, we have constructed an auxotrophic mutant based on pyrEF, which encodes the pyrimidine biosynthetic enzymes orotate phosphoribosyltransferase and orotidine-5'-monophosphate decarboxylase. S. acidocaldarius was shown to be sensitive to 5-fluoroorotic acid (5-FOA), which can be selected for mutations in pyrEF genes within a pyrimidine biosynthesis cluster. Spontaneous 5-FOA-resistant mutants by ultraviolet, KH1U and KH2U, were found to contain two point mutations and a frame shift mutation in pyrE, respectively. Mutations at these sites from KH1U and KH2U decreased the activity of orotate phosphoribosyltransferase encoded by the pyrE gene and blocked the degradation of 5-FOA into toxic 5-FOMP and 5-FUMP that kill the cells. Therefore, KH1U and KH2U were uracil auxotrophs. Transformation of Sulfolobus-Escherichia coli shuttle vector pC bearing pyrEF genes from S. solfataricus P2 into S. acidocaldarius mutant KH2U restored 5-FOA sensitivity and overcame the uracil auxotrophy. This study establishes an efficient genetic strategy towards the systematic knockout of genes in S. acidocaldarius.

• Current Research on Agriculture and Life Sciences
• /
• v.24
• /
• pp.1-8
• /
• 2006

When tea trees were introduced to Korea peninsular from China? Historically, Mr. Taeryum, an envoy of Shilla dynasty brought tea seeds from China during Tang dynasty and the seeds were planted at Jiri Mt. by the order of King Heungduk at AD828. During Koryo Dynasty(918 1392), Buddhism spread rapidly all over the country and the tea culture reached its highest stage of prosperity. At the Chosun Dynasty, however, the ceremonial drinking of tea vanished almost completely due to the flourishing Confucian tradition, a kind of substitution of Buddhism. But a few people have supported the traditional tea culture by themselves. Since the independence of Korea soon after the World War II at 1945, Korean War have been exploded at 1950. After economic evolution have been succeeded at 1980, the cultivation area of tea trees has been increased about 2,000ha and the cultural tradition of tea drinking has become popular again at a tea consume quantities amounted to 100g per capita at 2004. The northern limited area of tea plant is lined on the southern part of Korea peninsular. It is very small region compared to China about one million ha and to Japan over 60 thousand ha. It is problem not only the area of tea fields but also the methodology of tea cultivation, for examples without clonal cultivars and mechanical systems. WTO treatments was discussing with Korea, China and Japan government at 2005. Green tea custom is very high at 514% in Korea. If three countries will be agreed the imported tax will be cut off, the Korean tea farmers will be confused because of unstable situation of tea markets. All most of tea farmers should be made the tea fields by seeding not clonal propagation. Because of clonal cultivars have not developed in Korea, there have not been the research institutes for tea plants and manufactures before 1992. Now there are three research institute of tea in Korea; Tea Experiment Station at Bosung of Jeonnam Agricultural Research & Extension Services, Mokpo Experimental Station of National Institute of Crop Science, and Green Tea Cluster Institute of Hadong. Mokpo and Hadong Research Station were established at 2004 and at 2005 but Bosung Station was established at 1992. Seven clonal tea cultivers were selected at Bosung Station; Bohyang, Myngsun, Chanlok, Sunhyang, Mihyang, Jinhyang and Ohsun until 2004. Mokpo Experimental Institute was started the tea provenance testing about 4 provenances: Kangwon-do, Jeonlabuk-do, Jeonlanam-do, and Kyungsangnam-do. Korean new tea cultivers should be selected because Koran wild tea population have been high genetic variation. If tea breeding research will be successful to select new clonal cultivers, the tea farmers of Korea will be stable after WTO treatment with each country.

• Korean Journal of Veterinary Service
• /
• v.41 no.3
• /
• pp.149-155
• /
• 2018

Salmonella Enteritidis (S. Enteritidis) are found in animals, humans, and environment. In addition, S. Enteritidis draws attention to the public health concerns due to carriage of antibiotic resistance traits. For these reasons, the prevalence and antibiotic resistance patterns of S. Enteritidis are significant issues with regard to public health. To address this issues, a total of 24 strains of S. Enteritidis from 164 samples collected from several slaughterhouses in Gyeong-Nam province in order for antibiotic resistance profiles. Subsequently, we characterized the genotyping by random amplification polymorphic DNA (RAPD)-PCR. As a result, very high level of resistance to protein synthesis inhibition antibiotics and most isolates were susceptible to others. Six random primers were used for RAPD-PCR to reveal genotypes of S. Enteritidis isolates. One of the primer, P1245, generated 147 distinct RAPD-PCR fragments ranging from 400~3000 bp. The number of RAPD-PCR products ranged from 4 to 8 for this primer. The RAPD-PCR fragments could be placed these strains into 3 subgroups and 2 classes by UPGMA cluster analysis. Interestingly, several S. Enteritidis that isolated from different slaughterhouses showed same genotype. These results showed only limited genetic variation among the isolates, those were grouped into a few different patterns of antibiotic resistance.

• The Journal of the Korean Society for Microbiology
• /
• v.34 no.6
• /
• pp.533-542
• /
• 1999

H. pylori produces urease abundantly amounting to 6% of total protein of bacterial mass. Urease genes are composed of a cluster of 9 genes of ureC, ureD, ureA, ureB, ureI, ureE, ureF, ureG, ureH. Production of H. pylori urease in E. coli was studied with genetic cotransformation. Structural genes ureA and ureB produce urease apoprotein in E. coli but the apoprotein has no enzymatic activity. ureC and ureD do not affect urease production nor enzyme activity ureF, ureG, and ureH are essential to produce the catalytically active H. pylori urease of structural genes (ureA and ureB) in E.coli. The kinetics of activation of H. pylori urease apoprotein were examined to understand the production of active H. pylori urease. Activation of H. pylori urease apoprotein, pH dependency, reversibility of $CO_2$ binding, irreversibility of $CO_2$ and $Ni^{2+}$ incorporation, and $CO_2$ dependency of initial rate of urease activity have been observed in vitro. The intrinsic reactivity (ko) for carbamylation of urease apoprotein co expressed with accessory genes was 17-fold greater than that of urease apoprotein expressed without accessory genes. It is concluded that accessory genes function in maximizing the carbamylating deprotonated ${\varepsilon}$-amino group of Lys 219 of urease B subunit and metallocenter of urease apoprotein is supposed to be assembled by reaction of a deprotonated protein side chain with an activating $CO_2$ molecule to generate ligands that facilitate productive nickel binding.

• Korean Journal of Microbiology
• /
• v.41 no.3
• /
• pp.195-200
• /
• 2005

Comamonas sp. strain DJ-12 is a bacterial isolate capable of degrading of 4-chlorobiphenyl (4CB) as a carbon and energy source. The degradation pathway was characterized as being conducted by consecutive reactions of the meta-degradation of 4CB, hydrolytic dechlorination of 4-chlorobenzoate (4CBA), hydroxylation of 4-hydroxybenzoate, and meta-degradation of protocatechuate to product TCA metabolites. The 6.8 kb fragment from the chromosomal DNA of Comamonas sp. strain DJ-12 included the genes encoding for the meta-degradation of PCA; the genes of protocatechuate 4,5-dioxygenase alpha and beta subunits (pmcA and pmcB), 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase (pmcC), 2-pyrone-4,6-dicarboxylate hydrolase (pmcD), 4-oxalomesaconate (OMA) hydratase(pmcE), 4-oxalocitramalate (OCM) aldolase (pmcF), and transporter gene (pmcT). They were organized in the order of pmcT-pmcE-pmcF-pmcD-pmcA-pmcB-pmcC. The amino acid sequences deduced from the nucleotide sequences of pmcABCDEFT genes from Comamonas sp. strain DJ-12 exhibited 94 to $98\%$ homologies with those of Comamonas testosteroni BR6020 and Pseudomonas ochraceae NGJ1, but only 52 to $74\%$ with homologies Sphingomonas paucimobilis SYK-6, Sphingomonas sp. LB126, and Arthrobacter keyseri 12B.