• The Korean Journal of Mycology
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• v.23 no.2 s.73
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• pp.190-195
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• 1995

For the screening of biocontrol agents against red-pepper anthracnose (Colletotrichum gloeosporioides Penz) 248 isolates of bacteria, 51 of fungi and 30 of yeasts were obtained from phyllospere of medicinal plants. Of isolated microorganisms, four bacterial isolates, KB6, KB12, KB13 and KB14 were highly antagonistic to C. gloeosporioides than the others through dual culture test on potato dextrose agar (PDA). Among the four bacterial isolates, culture filtrate of the isolate KB12 showed the highest inhibition of C. gloeosporioides on PDA. The culture filtrates of four isolates controlled anthracnose on the red fruits, but not on the green fruits. In the living bacterial cell test, high control effect was observed both on the red and the green fruits. In the biochemical test, all isolates were identified as Bacillus subtilis.

• Korean Journal of Veterinary Research
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• v.33 no.2
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• pp.199-209
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• 1993

The effects of ${\alpha}_1$-adrenergic stimulation on membrane potential, intracellular sodium activity $(a_N{^i{_a}})$, and contractility were investigated in the isolated papillary muscle of euthyroid, hyperthyroid, and hypothyroid guinea pigs. Cardiac alterations in the thyroid state have been shown to induce marked changes in action potential characteristics, the most pronounced shortening of action potential duration by hyperthyroidism and an increase in duration by hypothyroidism. $10^{-5}M$ Phenylephrine produced a decrease in $(a_N{^i{_a}})$ in euthyroid and hypothyroid preparations, but an increase in $(a_N{^i{_a}})$ in hyperthyroid ones. The major findings were that phenylephrine produced a stronger positive inotropic effect(PIE) without initial negative inotropic effect(NIE) in hyperthyroid preparations, while phenylephrine produced markedly NIE in hypothyroid ones. The alterations in membrane potential, $(a_N{^i{_a}})$, and contractility were abolished by $3{\times}10^{-5}M$ prazosin in hypothyroidism. In hypothyroid ventricular muscle, the decrease in $(a_N{^i{_a}})$ caused by phenylephrine were not abolished or reduced by $10^{-5}M$ strophanthidin, $10^{-5}M$ TTX, $3{\times}10^{-4}M$ lidocaine, or $100^{-5}M$ verapamil. These results indicate that the ${\alpha}_1$-adrenoceptor-mediated decrease in $(a_N{^i{_a}})$ is not associated with a stimulation of the $Na^+$-$K^+$ pump, inhibition of the $Na^+$ or $Ca^+$ channel in hypothyroid ventricular muscle. $10^{-5}M$ Phenylephrine decreased $(a_N{^i{_a}})$ but increased $(a_N{^i{_a}})$ in the presence of a PKC activator phorbol dibutyrate$(PDB_u)$. In conclusion, it is suggested that the following sequence of events in response to phenyleplhane occur in guinea pig ventricular muscle. First, changes in thyroid state may contribute to the ventacular electrophysiological propeties or ion transport system. Second, the adrenoceptor-mediated initial transient NIE may be associated with the decrease in $(a_N{^i{_a}})$ by PKC activation.

• Journal of Integrative Natural Science
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• v.3 no.2
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• pp.72-77
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• 2010

Alginate lyases, also known as alginases or alginate depolymerases, catalyze the degradation of alginate by a ${\beta}$-elimination mechanism that has yet to be fully elucidated. Alginate is a copolymer of ${\alpha}$-L-guluronate (G) and its C5 epimer ${\beta}$-D-mannuronate (M), arranged as homopolymeric G blocks, M blocks, alternating GM or random heteropolymeric G/M stretches. Almost all alginate lyases depolymerize alginate in an endolytical fashion via a ${\beta}$-elimination reaction. The alginate lyase Atu3025 from Agrobacterium tumefaciens strain C58, consisting of 776 amino-acid residues, is a novel exotype alginate lyase classified into polysaccharide lyase family 15. Till now there is no crystal structure available for this class of proteins. Since there is no template with high sequence identity, three-dimensional coordinates for exotype alginate lyase (PL 15 family) were determined using modeling methods (Comparitive modeling and Fold recognition). The structures were modeled using the X-ray coordinates from Heparinase protein family (PDB code: 3E7J). This enzyme (Atu3025) displays enzymatic activity for both poly-M and poly-G alginate. Since poly-M is widespread; docking of a tri-mannuronate against the modeled structure was performed. We identified some of those residues which are crucial for lyase activity. The results from this study should guide future mutagenesis studies and also provides a starting point for further proceedings.

• Genomics & Informatics
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• v.14 no.3
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• pp.112-124
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• 2016

Solid tumor is generally observed in tissues of epithelial or endothelial cells of lung, breast, prostate, pancreases, colorectal, stomach, and bladder, where several genes transcription is regulated by the microRNAs (miRNAs). Argonaute (AGO) protein is a family of protein which assists in miRNAs to bind with mRNAs of the target genes. Hence, study of the binding mechanism between AGO protein and miRNAs, and also with miRNAs-mRNAs duplex is crucial for understanding the RNA silencing mechanism. In the current work, 64 genes and 23 miRNAs have been selected from literatures, whose deregulation is well established in seven types of solid cancer like lung, breast, prostate, pancreases, colorectal, stomach, and bladder cancer. In silico study reveals, miRNAs namely, miR-106a, miR-21, and miR-29b-2 have a strong binding affinity towards PTEN, TGFBR2, and VEGFA genes, respectively, suggested as important factors in RNA silencing mechanism. Furthermore, interaction between AGO protein (PDB ID-3F73, chain A) with selected miRNAs and with miRNAs-mRNAs duplex were studied computationally to understand their binding at molecular level. The residual interaction and hydrogen bonding are inspected in Discovery Studio 3.5 suites. The current investigation throws light on understanding miRNAs based gene silencing mechanism in solid cancer.

• Journal of the Mineralogical Society of Korea
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• v.17 no.1
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• pp.61-73
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• 2004

The purposes of this study are to investigate the occurrence, the hydrochemical characteristics and the origin of the $CO_2$-rich springs from the Kangwon Province, and to reanalyze the previous studied results of other researchers. The $CO_2$-rich water samples were collected at 13 locations in the Kangwon Province. The $CO_2$-rich water shows a high $CO_2$ concentration ($P_{CO2}$ 0.787 to 4.78 atm), weak acidic pHs, electrical conductivity values ranging from 422 to 2,280 $\mu$S/cm, and high Fe and F contents. The chemical compositions of $CO_2$-rich water from this study area are classified into three types; $Ca-HCO_3$, Ca(Na)-$HCO_3$, $Na-HCO_3$ types. The chemical data of $CO_2$-rich waters and their host rocks indicate that $Na-HCO_3$ type water are mainly influenced by biotite, K-feldspar granite, and Ca(Na)-HC $O_3$, type water is chiefly influenced by gneiss and carbonate minerals in granite. F and Fe contents of $CO_2$-rich waters are abundant in $Na-HCO_3$, and $Ca-HCO_3$ types, respectively. The results of this study suggest that the chemical composition $CO_2$-rich water is mainly controlled by the mineralogical composition of aquifer host rocks. Oxygen and deuterium isotope data indicate that $CO_2$-rich water is meteoric origin. The $\delta^{13}$C values (-0.3$\textperthousand$ to -6.2$\textperthousand$ PDB) suggest that dissolved carbonates are mainly derived from a deep-seated $CO_2$ and partly from carbonate minerals.

• Journal of Life Science
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• v.23 no.8
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• pp.1010-1018
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• 2013

The greenhouse whitefly, Bemisia tabaci, is considered one of the most destructive pests of crops. In this study, we aimed to determine the optimal liquid culture conditions in shake flasks for maximal sporulation of Beauveria bassiana M130 using rice bran. The optimal initial pH for the spore production of B. bassiana using extracted rice bran medium was 5.2 and $28^{\circ}C$. The screening in shake flasks of carbon and nitrogen sources resulted in the identification of an optimal medium based on 0.5% $(NH_4)_2SO_4$, with extracted rice bran 8:1. Using this medium, a production level of $2.15{\times}10^9$ spores per ml was obtained after six days from culture inoculation at $28^{\circ}C$ in a rotary shaking incubator at 130 rpm. In addition, the specific activities of extracellular enzymes of chitinase and protease were $4,296{\mu}mol$ and $375{\mu}mol$, respectively. These results suggest that Beauveria bassiana M130 could be a bio-controller for the greenhouse whitefly.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2119-2128
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• 2017

Citrinin (CIT) is a toxic secondary metabolite produced by fungi belonging to the Penicillium, Aspergillus, and Monascus spp. This toxin has been detected in many agricultural products. In this study, a strain Y3 with the ability to eliminate CIT was screened and identified as Cryptococcus podzolicus, based on the sequence analysis of the internal transcribed spacer region. Neither uptake of CIT by cells nor adsorption by cell wall was involved in CIT elimination by Cryptococcus podzolicus Y3. The extracellular metabolites of Cryptococcus podzolicus Y3 stimulated by CIT or not showed no degradation for CIT. It indicated that CIT elimination was attributed to the degradation of intracellular enzyme(s). The degradation of CIT by C. podzolicus Y3 was dependent on the type of media, yeast concentration, temperature, pH, and initial concentration of CIT. Most of the CIT was degraded by C. podzolicus Y3 in NYDB medium at 42 h but not in PDB medium. The degradation rate of CIT was the highest (94%) when the concentration of C. podzolicus Y3 was $1{\times}10^8cells/ml$. The quantity of CIT degradation was highest at $28^{\circ}C$, and there was no degradation observed at 3$5^{\circ}C$. The study also showed that acidic condition (pH 4.0) was the most favorable for CIT degradation by C. podzolicus Y3. The degradation rate of CIT increased to 98% as the concentration of CIT was increased to $20{\mu}g/ml$. The toxicity of CIT degradation product(s) toward HEK293 was much lower than that of CIT.

• The Korean Journal of Mycology
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• v.40 no.2
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• pp.98-103
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• 2012

This study has been conducted to screen the decolorization of 4 aromatic synthetic dyes and production of ligninolytic enzymes by 4 white rot fungi such as Bjerkanderia adusta, Cerrena unicolor, Pleurotus pulmonarius and Abortiporus biennis. It was found that B. adusta, C. unicolor, and P. pulmonarius have the ability to efficiently decolorize congo red and moderately decolorized amaranth and orange G in solid and liquid culture media. However, the decolorization rate of 4 synthetic dyes by A. biennis was relatively low. The decolorization of congo red, amaranth, orange G were related to the growth rate of the fungal mycelia in the solid medium. But, the all fungi tested did not efficiently decolorize methylene blue in the liquid culture media. To investigate the production of ligninolytic enzymes in media containing aromatic compounds, fungi were cultured in 1% naphthalene supplemented potato dextrose broth medium. All fungi tested had the capability to produce laccase, lignin peroxidase and manganese peroxidase, and B. adusta was the best ligninolytic enzymes producing white rot fungus among other fungi tested.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.1
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• pp.40-46
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• 2013

The isotope ratios of $^{13}C/^{12}C$ and $^{18}O/^{16}O$ for a sample in a mass spectrometer are measured relative to those of a pure $CO_2$ reference gas (i.e., laboratory working standard). Thus, the calibration of a laboratory working standard gas to the international isotope scales (Pee Dee Belemnite (PDB) for ${\delta}^{13}C$ and Vienna Standard Mean Ocean Water (V-SMOW) for ${\delta}^{18}O$) is essential for comparisons between data sets obtained by other groups on other mass spectrometers. However, one often finds difficulties in getting well-calibrated standard gases, because of their production time and high price. Additional difficulty is that fractionation processes can occur inside the gas cylinder most likely due to pressure drop in long-term use. Therefore, studies on laboratory production of pure $CO_2$ isotope standard gas from stable solid calcium carbonate standard materials, have been performed. For this study, we propose a method to extract pure $CO_2$ gas without isotope fractionation from a solid calcium carbonate material. The method is similar to that suggested by Coplen et al., (1983), but is better optimized particularly to make a large amount of pure $CO_2$ gas from calcium carbonate material. The $CaCO_3$ releases $CO_2$ in reaction with 100% pure phosphoric acid at $25^{\circ}C$ in a custom designed, evacuated reaction vessel. Here we introduce optimal procedure, reaction conditions, and samples/reactants size for calcium carbonate-phosphoric acid reaction and also provide the details for extracting, purifying and collecting $CO_2$ gas out of the reaction vessel. The measurements for ${\delta}^{18}O$ and ${\delta}^{13}C$ of $CO_2$ were performed at Seoul National University using a stable isotope ratio mass spectrometer (VG Isotech, SIRA Series II) operated in dual-inlet mode. The entire analysis precisions for ${\delta}^{18}O$ and ${\delta}^{13}C$ were evaluated based on the standard deviations of multiple measurements on 15 separate samples of purified $CO_2$. The pure $CO_2$ samples were taken from 100-mg aliquots of a solid calcium carbonate (Solenhofen-ori $CaCO_3$) during 8-day experimental period. The multiple measurements yielded the $1{\sigma}$ precisions of ${\pm}0.01$‰ for ${\delta}^{13}C$ and ${\pm}0.05$‰ for ${\delta}^{18}O$, comparable to the internal instrumental precisions of SIRA. Therefore, we conclude the method proposed in this study can serve as a way to produce an accurate secondary and/or laboratory $CO_2$ standard gas. We hope this study helps resolve difficulties in placing a laboratory working standard onto the international isotope scales and does make accurate comparisons with other data sets from other groups.

• Journal of Mushroom
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• v.6 no.1
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• pp.32-37
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• 2008

This study was carried out to investigate the growth inhibition of Propionibacterium acnes by mycelial culture broth of Paecilomyces japonica in the Mulberry leaf extract. The growth inhibition effect of P. japonica mycelial culture broth against P. acnes in various concentration of Mulberry leaf extract was the most effective in 3% Mulberry leaf extract. The inhibition effect of P. japonica mycelial culture broth against P. acnes according to the culture time was the moust effective after 25 days mycelial cultivation. As the treating amount of the mycelial culture broth was increased, the growth inhibition effect against P. acnes was increased gradually. The growth inhibition effect of mycelial culture broth against P. acnes according to the time of heat treatment was active by 45min at $100^{\circ}C$, while it was inactive more than 60min at $100^{\circ}C$. This result suggested that the antibacterial materials are possible to be glycoside or peptides. Taken together P. japonica mycelial culture in the Mulbarry leaf extract has a possibility to be an element of skin-care cosmetics regulating the acnes.