• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.998-1003
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• 2014

Aspartate aminotransferase (AST; E.C. 2.6.1.1), a vitamin B6-dependent enzyme, preferentially promotes the mutual transformation of aspartate and ${\alpha}$-ketoglutarate to oxaloacetate and glutamate. It plays a key role in amino acid metabolism and has been widely recommended as a biomarker of liver and heart damage. Our study aimed to evaluate the extensive preparation of AST and its application in quality control in clinical laboratories. We describe a scheme to express and purify the 6His-AST fusion protein. An optimized sequence coding AST was synthesized and transformed into Escherichia coli BL21 (DE3) strain for protein expression. Ideally, the fusion protein has a volumetric productivity achieving 900 mg/l cultures. After affinity chromatography, the enzyme activity of purified AST reached 150,000 U/L. Commutability assessment between the engineered AST and standard AST from Roche suggested that the engineered AST was the better candidate for the reference material. Moreover, the AST showed high stability during long-term storage at $-20^{\circ}C$. In conclusion, the highly soluble 6His-tagged AST can become a convenient tool for supplying a much better and cheaper standard or reference material for the clinical laboratory.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.509-516
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• 2007

Starters of lactic acid bacteria(LAB) were isolated from the commercial yoghurt products and the four isolates have been studied on their identification and some physiological characteristics. For the purpose of identification, microscopic examination, API test, and 16s rRNA gene sequencing were conducted. Isolate A from a yogurt product of local dairy company A was shown to be Gram-positive rod-shaped bacterium. All strains isolated were turned out to be as Lactobacillus paracasei by using a API 50 CHL kit. In contrast, isolate A was identified as a strain of Lactobacillus helveticus based on the 16S rRNA sequencing data, and L. casei ssp. casei for both B and D and L. paracasei for C. All the isolates survived the simulated gastric juice, pH 2.0 within 3 hours and sharply decreased in viability so that no viable cell was observed after 4.5 hours incubation. In addition, the four isolated strains were almost identical in antibiotic susceptibility to six different kinds of antibiotics including erythromycin ($15\;{\mu}g$), ampicillin ($10\;{\mu}g$), gentamycin ($10\;{\mu}g$), neomycin ($30\;{\mu}g$), but rather resistant to colistin ($10\;{\mu}g$) and streptomycin ($10\;{\mu}g$). It was noteworthy that four isolates were confirmed to produce antibacterial substance against foodborne pathogens of Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli 0157:H7 as test organisms based on the inhibitory zones on an MRS soft agar medium. At presence, the inhibitory factor is unknown so that further studies are required to ascertain the active factor responsible for the inhibitory activities.

• The Plant Pathology Journal
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• v.31 no.3
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• pp.245-251
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• 2015

Alternative hosts increase the difficulty of disease management in crops because these alternate hosts provide additional sources of primary inoculum or refuges for diversity in the pathogen gene pool. Agropyron cristatum (crested wheatgrass), Bromus inermis (smooth bromegrass), Pascopyrum smithii (western wheatgrass), Stipa viridula (green needlegrass), and Thinopyrum intermedium (intermediate wheatgrass), commonly identified in range, prairie, verge, and soil reclamation habitats, serve as additional hosts for Pyrenophora tritici-repentis, the cause of tan spot in wheat (Triticum aestivum L.). A. cristatum (five lines), B. inermis (seven lines), P. smithii (four lines), S. viridula (two lines), and T. intermedium (six lines) were tested for their reactions to 30 representative P. tritici-repentis isolates from races 1-5. Plants were grown until the two-three-leaf stage in a greenhouse, inoculated individually with the 30 isolates, held at high humidity for 24 h, and rated after 7 days. All lines developed lesion types 1-2 (resistant) based on a 1-5 rating scale. Also, leaves from an additional plant set were infiltrated with two host selective toxins, Ptr ToxA as a pure preparation and Ptr ToxB as a dilute crude culture filtrate. All lines were insensitive to the toxins. Results indicate that these grass hosts have a limited or nonsignificant role in tan spot epidemiology on wheat in the northern Great Plains. Additionally, the resistant reactions demonstrated by the grass species in this research indicate the presence of resistance genes that can be valuable to wheat breeding programs for improving wheat resistance to P. tritici-repentis.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.632-637
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• 2006

Oviduct-specific glycoprotein 1 (OVGP1) is implicated in playing a role in fertilization and early embryo development. In this study, we have obtained the sequence of intron 9 of OVGP1 gene in swine. Comparative sequencing of Meishan (a native Chinese breed) and Large White pig breeds revealed an A/T substitution at position 943. A PCR-EcoRI-RFLP assay was developed to detect this mutation. Polymorphism analysis in Qingping animals showed that pigs with BB genotype had lower number of piglets born alive (NBA) in multiple parities than pigs with AA (p<0.05) and AB genotype (p<0.01). In Large $White{\times}Meishan$ ($LW{\times}M$) $F_2$ offspring, the weight of both ovaries (OW) of the BB genotype was significantly lighter than that of AB (p = 0.05) and AA (p<0.01) genotypes. Analysis of the data also revealed that the mutation locus affected these two traits mostly by additive effects. These studies indicated that the polymorphism was associated with NBA and OW in two distinct populations and further investigations in more purebreds or crossbreds are needed to confirm these results.

• BMB Reports
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• v.40 no.1
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• pp.22-28
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• 2007

MyoD, expressed in skeletal muscle lineages of vertebrate embryo, is one of muscle-specific basic helix-loop-helix (bHLH) transcription factors, which plays a key role in the determination and differentiation of all skeletal muscle lineages. In this study, a cDNA of grass carp MyoD was cloned and characterized from total RNA of grass carp embryos by RT-PCR. The full-length cDNA of grass carp MyoD is 1597 bp. The cDNA sequence analysis reveals an open reading frame of 825 bp coding for a protein of 275 amino acids, which includes a bHLH domain composed of basic domain (1-84th amino acids) and HLH domain (98-142th amino acids), without signal peptide. Then the MyoD cDNA of grass carp was cloned to yeast expression vector pPICZ$\alpha$A and transformed into P. pastoris GS115 strain, the recombinant MyoD protein with a molecular weight of about 31KD was obtained after inducing for 2d with 0.5% methanol in pH 8.0 BMGY medium, and the maximum yield was about 250 mg/L in shaking-flask fermentation. The results were expected to benefit for further studies on the crystal structure and physiological function of fish MyoD.

• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.317-331
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• 2016

Development of disease resistant plant is one of the important objectives in rice breeding programs because biotic stresses can adversely affect rice growth and yield losses. This study was conducted to identify lines with multiple-resistance genes to biotic stress among 173 hybrid rice breeding lines and germplasms using DNA-based markers. Our results showed that one hybrid rice line [IR98161-2-1-1-k1-3 (IR86409-3-1-1-1-1-1/IRBB66)] possessed 5 bacterial blight resistance genes (Xa4, xa5, Xa7, Xa13 and Xa21) while two hybrid rice lines [IR98161-2-1-1-k1-2 (IR86409-3-1-1-1-1-1/IRBB66) and 7292s (IR75589-31-27-8-33S(S1)/IR102758B)] possessed 3 bacterial blight resistance genes (Xa4, Xa7 and Xa21, and Xa3, Xa4 and xa5). Molecular survey on rice blast disease revealed that most of these lines had two different resistant genes. Only 11 lines possessed Pib, Pi-5, and Pi-ta. In addition, we further surveyed the distribution of insect resistant genes, such as Bph1, Bph18(t), and Wbph. Three hybrid breeding lines [IR98161-2-1-1-k1-3 (IR86409-3-1-1-1-1-1/IRBB66), IR98161-2-1-1-k1-2 (IR86409-3-1-1-1-1-1/IRBB66), and 7292s (IR75589-31-27-8-33S(S1) /IR102758B)] contained all three resistance genes. Finally, we obtained four hybrid rice breeding lines and germplasms [IR98161-2-1-1-k1-2 (IR86409-3-1-1-1-1-1/IRBB66), Damm-Noeub Khmau, 7290s, and 7292s (IR75589-31-27-8-33S(S1)/IR102758B)] possessing six-gene combination. They are expected to provide higher level of multiple resistance to biotic stress. This study is important for genotyping hybrid rice with resistance to diverse diseases and pests. Results obtained in this study suggest that identification of pyramided resistance genes is very important for screening hybrid rice breeding lines and germplasms accurately for disease and pest resistance. We will expand their cultivation safely through bioassays against diseases, pests, and disaster in its main export countries.

• Journal of Life Science
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• v.14 no.6 s.67
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• pp.906-912
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• 2004

Helicobacter pylori infection is highly prevalent, as high as 2/3 of whole population infected, in Korea. H. pylori infection initiates inflammation by induction of interleukin-8 through type IV secretion of CagA. It was recently suggested that induction failure of IL-8 is not associated with defect in cag PAI but associated with cagE locus diversity. This study was designed to investigate ability of 11-8 in-duction according to sequence variation within the cagE gene, cagA TP motifs and vacA m-types in vitro study using AGS cell-line, and to evaluate its association with different clinical outcome. Seventy-four H. pylori stains were isolated from 23 patients with gastric cancer (Ca), 24 subjects with gastritis (G) and 27 patients with duodenal ulcer (Du) in Kangnam St. Mary's Hospital, Seoul, Korea. cagE gene diversity was confirmed by the PCR-RFLP methods with MboI/NlaIII and tyrosine phosphate motifs (TPMs) of cagA was determined TPM-A and C by using DdeI/Tsp5091 restriction enzyme and TPM-B was determend by Real time PCR the method of Owen et al. and IL-8 was measured by ELISA assay. IL-8 activity was positively detected in 59 among 74 strains $(79.7\%)$. IL-8 secretion was significantly increased in MboI A and MboI B type compared to MboI C type and in MboI/NlaIII A-C and B-C type than C-C type. 1L-8 activity was not associated with either the number or composition of cagA tyrosine phosphorylation motifs and vacA m-type. There was no significant difference in IL-8 activity among patient groups. cagE gene diversity is thought to be mainly associated with the induction of IL-8 in H. pylori infection.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.2
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• pp.209-219
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• 2003

An experiment was initiated to evaluate hybrid vigour in twelve F$_1$ hybrids and seven three-way crosses of multivoltine ${\times}$ bivoltine silkworm between newly evolved multivoltine breed BL67 with productive bivoltine CSR breeds and hybrids. Analysis of variances computed for different characters among F$_1$hybrids and three-way crosses showed highly significant differences among them indicating presence of both additive and non-additive gene actions for the expression of these characters. Among twelve F$_1$ hybrids, two F$_1$ hybrids viz., BL67${\times}$CSR$_4$and BL67${\times}$CSR$_{5}$ have expressed significant heterosis for nine characters and two hybrids viz., BL67${\times}$NB$_4$D$_2$and PM${\times}$NB$_4$D$_2$ for eight characters whereas out of nine three-way crosses, three hybrids viz., BL67${\times}$ (CSR$_3$${\times}$CSR$_{6}$), BL67${\times}$(CSR$_{16}$${\times}$CRS$_{17}$) and BL67${\times}$(CSR$_{18}$ ${\times}$CSR$_{19}$) expressed significant heterosis for eight characters. In the present study, it is observed that the cocoons of two hybrids viz., BL67${\times}$CSR$_4$and BL67${\times}$CSR$_{19}$ were found to be uniform as these hybrids showed lowest CV％ (5.35 and 5.38) among twelve F$_1$ hybrids and seven three way crosses between multivoltine ${\times}$ bivoltine hybrids. Four F$_1$ hybrids viz., BL67${\times}$CSR$_4$, BL67${\times}$CSR$_{5}$, BL67${\times}$ (CSR$_3$${\times}$CSR$_{6}$), BL67${\times}$(CSR$_{16}$${\times}$CRS$_{17}$) and BL67${\times}$(CSR$_{18}$ ${\times}$CSR$_{19}$) showed superiority in expressing hybrid vigour and are considered as best heterotic hybrids for commercial exploitation.ion.ation.ion.ation.ion.

• Journal of Plant Biotechnology
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• v.37 no.1
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• pp.102-109
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• 2010

Fructan has been found to accumulate in various tissues during periods when light levels increased carbon fixation where low temperatures reduced growth rates while photosynthesis continued. In this study, we have cloned 1-sucrose:sucrose fructosyl transferase(1-sst) and 1-fructan: fructan fructosyl transferase (1-fft, a key enzyme for the synthesis of fuctan) from Jerusalem Artichoke (Helianthus tuberosus L.). The recombinant vector with 1-sst and 1-fft has been constructed under the control of 35S promoter of KJGV-B2 vector and transgenic plants obtained by Agrobacterium tumefaciens LBA4404. PCR analysis carried out on the putative transgenic plants for amplification of the coding region of specific gene (1-sst, 1-fft), and HPT genes. Transgenic lines carrying of 1-sst and 1-fft were confirmed for integration into the rice genome using Southern blot hybridization and RT-PCR. The transgenic plants in $T_2$ generation were selected and expression pattern analysis revealed that 1-sst and 1-fft were stable. This analysis confirmed the presence of low-molecular-weight fructan in the seedling of the transgenic rices. Therefore, cold tolerance and carbohydrate metabolism will be possible to develop resistant plants using the transgenic rice.

• Microbiology and Biotechnology Letters
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• v.34 no.4
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• pp.342-351
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• 2006

The aim of this study was to survey susceptibilities of Escherichia coli and Klebsiella pneumoniae isolates against cefotaxime and to determine the prevalences of CTX-M type extended-spectrum $\beta$-lactamases (ESBLs) producing E. coli and K. pneumoniae in Korea. During the period of February to July, 2005, 153 E. coli and 52 K. neumoniae isolates were collected from 2 hospitals in Busan. Antimicrobial susceptibilities to cefotaxime were tested by the disk diffusion method. ESBL production of E. coli and K. pneumoniae was determined by the double disk synergy test. MICs of $\beta$-lactam antibiotics were determined by the agar dilution method. Blac$_{CTX-M}$ genes of the organism were detected by PCR. Among 153 isolates of E. coli and 52 isolates of K. neumoniae, 27 (17.6%) and 25 (48.0%) were intermediate or resistant to cefotaxime, respectively. Twenty-three (15.0%) isolates out of 153 E. coli and 13 (25.0%) out of 52 K. neumoniae isolates showed positive results for ESBL by the double disk synergy test. Twenty isolates out of 23 ESBL producing E. coli and 12 out of 13 ESBL producing K. neumoniae isolates harbored biacTx-M gene,11 of ESBL producing E. coli and 12 of ESBL producing K. neuinoniae isolates harbored bla$_{CTX-M}$ gene, 11 of the ESBL producing E. coli and 2 of ESBL producing K. neumoniae isolates harbored bla$_{TEM}$ gene, and 1 of the ESBL producing E. coli and 12 of ESBL producing K. neumoniae isolates harbored bla$_{SHV}$ gene. E. coli and K. neumoniae isolates producing CTX-M-type ESBLs were not uncommon in Korea. It is thought that continuous survey are necessary for inspecting the spread and novel variants of CTX-M-type ESBL genes. Further me]'e investigation and research on ESBL producing strains are needed in order to prevent the spread of resistant bacteria.