• Toxicological Research
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• 제17권
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• pp.271-280
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• 2001

We report on the applicability oj a method recently developed in our laboratory for measuring the antioxidant potential of isolated chemicals and extracts derived from natural products. Peroxyl radicals generated by thermal homolysis of 2,2'-azobis-amidinopropane (ABAP) oxidize $\alpha$-keto-${\gamma}$-methiolbutyric acid (KMBA) to ethylene, which is monitored by gas chromatography. Inhibition of ethylene formation in the presence of antioxidants that compete with KMBA for peroxyl radicals is the basis of the Total Oxyradical Scavenging Capacity Assay (TOSCA; Winston et al., 1998). Antioxidative activities of water-soluble extracts of American green tea, the anti-hepatotoxic flavonolignan from milk thistle (Silybum marianum) silybin, Ginkgo biloba extract EGb 761, and a series of naturally occuring sesquiterpene lactones (all ger-macranolides found in in fungi, liverworts, and plants) were studied. The specific TOSC value per $\mu$M silybin was 5.2, which is essentially comparable to that of Trolo $x^{ⓡ}$, a water-soluble vitamine E analog. Tea and Ginkgo extracts exhibited potent peroxyl radical scavenging capacity with values, respectively of =1700 and 1000 $\mu$mols Trolo $x^{ⓡ}$ equivalent per gram dry matter. The known anti-inflammatory activity of some germacranolides prompted study of their antioxidant capacity. None of the lactones exhibited antioxidant capacity toward peroxyl radicals comparable to Trolo $x^{ⓡ}$; costunilide, the most lipophilic, had a TOSC value = to glutathione. The potential role of peroxyl radicals in lipidperoxidation, other cellular damage, and var-ious disease states suggest a possible preventive role for silybin, green tea and Ginkgo biloba in oxidative stress caused by these free radical species.ecies.

• The Plant Pathology Journal
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• 제33권6호
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• pp.543-553
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• 2017

Sesame (Sesamum indicum) is an important oil seed crop of Asia. Yields can be negatively impacted by various factors, including disease, particularly those caused by fungi which create problems in both production and storage. Foliar diseases of sesame such as Alternaria leaf blight may cause significant yield losses, with reductions in plant health and seed quality. The work reported here determined the incidence of Alternaria species infecting sesame seeds grown in the Punjab, Pakistan. A total of 428 Alternaria isolates were obtained from 105 seed samples and grouped into 36 distinct taxonomic groups based on growth pattern and morphological characters. Isolation frequency and relative density of surface sterilized and non-surface sterilized seeds showed that three isolates (A13, A47 and A215) were the most common morphological groups present. These isolates were further identified using sequencing of the Internal Transcribed Spacer (ITS) region of ribosomal DNA (rDNA) and the Alternaria major allergen gene (Alt a 1). Whilst ITS of rDNA did not resolve the isolates into Alternaria species, the Alt a 1 sequences exhibited > 99% homology with Alternaria alternata (KP123850.1) in GenBank accessions. The pathogenicity and virulence of these isolates of Alternaria alternata was confirmed in inoculations of sesame plants resulting in typical symptoms of leaf blight disease. This work confirms the identity of a major source of sesame leaf blight in Pakistan which will aid in formulating effective disease management strategies.

• Journal of Microbiology and Biotechnology
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• 제21권4호
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• pp.412-420
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• 2011

Secretion of cellobiase occurred in a brefeldin A (BFA) uninhibited manner in the filamentous fungus Termitomyces clypeatus. Fluorescence confocal microscopy revealed that application of the drug at a concentration of 50 ${\mu}g$/ml caused arrest of Spitzenkorper assembly at the hyphal tip. This resulted in greater than 30% inhibition of total protein secretion in the culture medium. However, the cellobiase titer increased by 17%, and an additional 13% was localized in the vacuolar fraction en route secretion. The secretory vacuoles formed in the presence of the drug were also found to be bigger (68 nm) than those in the control cultures (40 nm). The enzyme secreted in the presence and absence of BFA revealed a single activity band in both cases in native PAGE and had similar molecular masses (approx. 120 kDa) in SDS-PAGE. The BFA enzyme retained 72% of native glycosylation. It also exhibited a higher stability and retained 98% activity at $50^{\circ}C$, 93.3% activity at pH 9, 63.64% activity in the presence of 1M guanidium hydrochloride, and 50% activity at a glucose concentration of 10 mg/ml in comparison to 68% activity, 75% activity, 36% activity, and 19% activity for the control enzyme, respectively. The observations collectively aimed at the operation of an alternative secretory pathway, distinct from the target of brefeldin A, which bypassed the Golgi apparatus, but still was able to deliver the cargo to the vacuoles for secretion. This can be utilized in selectively enhancing the yield and stability of glycosidases for a successful industrial recipe.

• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1687-1695
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• 2016

Ochratoxin A (OTA), a mycotoxin, contaminates agricultural products and poses a serious threat to public health worldwide. Microbiological methods are known to be a promising approach for OTA biodegradation because physical and chemical methods have practical limitations. In the present study, a total of 130 fungal isolates obtained from 65 traditional Korean meju (a fermented starter for fermentation of soybeans) samples were examined for OTA-biodegradation activity using thin-layer chromatography. Two fungal isolates were selected for OTA-biodegradation activity and were identified as Aspergillus tubingensis M036 and M074 through sequence analysis of the beta-tubulin gene. After culturing both A. tubingensis isolates in Soytone-Czapek medium containing OTA (40 ng/ml), OTA-biodegradation activity was analyzed using high-performance liquid chromatography (HPLC). Both A. tubingensis strains degraded OTA by more than 95.0% after 14 days, and the HPLC analysis showed that the OTA biodegradation by the A. tubingensis strains led to the production of ochratoxin α, which is much less toxic than OTA. Moreover, crude enzymes from the cultures of A. tubingensis M036 and M074 led to OTA biodegradation of 97.5% and 91.3% at pH 5, and 80.3% and 75.3% at pH 7, respectively, in a buffer solution containing OTA (40 ng/ml) after 24 h. In addition, the OTA-biodegrading fungi did not exhibit OTA production activity. Our data suggest that A. tubingensis isolates and their enzymes have the potential for practical application to reduce levels of OTA in food and feed.

• 한국미생물·생명공학회지
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• 제40권4호
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• pp.333-338
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• 2012

지의류는 곰팡이, 조류 및 남조균류의 공생체이다. 본 연구팀은 최근 북극 지의류로부터 분리한 몇몇 미생물 종의 항산화 활성에 대하여 연구하였고, 그들의 높은 항산화 활성을 확인하였다. 본 연구에서는 Cladonia sp., Sterocaulon sp., Umbilicaria sp. 및 Cetraria sp. 총 4종류의 지의류로부터 5종의 미생물을 새롭게 분리하였고 배양 후, 다양한 용매 추출법으로 그들의 항산화능을 조사하였다. DPPH와 ABTS 자유 라디컬 소거능 측정법 및 FRAP 분석 등을 수행하였다. 또한 총 폴리페놀함량과 총플라보노이드 함량 분석 역시 수행하였다. 지의류 유래 미생물 배양 추출액 중, Burkholderia sordidicola S5-B(T) 유사 미생물 종의 에틸아세테이트 추출액은 DPPH 분석에서 대조군인 아스코르빈산 (51.3%)에 비해 72.9%로 높은 항산화 활성을 보였을 뿐만 아니라, 높은 플라보노이드와 폴리페놀 함량을 나타내었다. 결과적으로, 이러한 지의류 유래 미생물 종들은 잠재적으로 천연 항산화제의 원천소재로서 이용가능할 것이다.

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1187-1196
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• 2013

Global warming will have far-reaching effects on our ecosystem. However, its effects on Antarctic soils have been poorly explored. To assess the effects of warming on microbial abundance and community composition, we sampled Antarctic soils from the King George Island in the Antarctic Peninsula and incubated these soils at elevated temperatures of $5^{\circ}C$ and $8^{\circ}C$ for 14 days. The reduction in total organic carbon and increase in soil respiration were attributed to the increased proliferation of Bacteria, Fungi, and Archaea. Interestingly, bacterial ammonia monooxygenase (amoA) genes were predominant over archaeal amoA, unlike in many other environments reported previously. Phylogenetic analyses of bacterial and archaeal amoA communities via clone libraries revealed that the diversity of amoA genes in Antarctic ammonia-oxidizing prokaryotic communities were temperature-insensitive. Interestingly, our data also showed that the amoA of Antarctic ammonia-oxidizing bacteria (AOB) communities differed from previously described amoA sequences of cultured isolates and clone library sequences, suggesting the presence of novel Antarctic-specific AOB communities. Denitrification-related genes were significantly reduced under warming conditions, whereas the abundance of amoA and nifH increased. Barcoded pyrosequencing of the bacterial 16S rRNA gene revealed that Proteobacteria, Acidobacteria, and Actinobacteria were the major phyla in Antarctic soils and the effect of short-term warming on the bacterial community was not apparent.

• 한국미생물·생명공학회지
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• 제27권4호
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• pp.311-319
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• 1999

Leaves of Aloe vera Linne and bloods of domestic animal were composted in a soild state fermentation reactor (SSFR) by using microbial additive including a bulking and moisture controlling agent. From solid-culture of microbial additive, 10 species of bacteria and 10 species of fungi were isolated and, their enzyme activities including amylase, carboxy methyl cellulase CMCase, lipase and protease were detected. Optimum fermentation conditions of Aloe leaves and domestic animal bloods in SSFR were obtained from the studies of response surface analysis employing microbial additive content, initial moisture content, and fermentation temperature as the independent variables. The optimum conditions for SSFR using Aloe leaves were obtained at 9.45$\pm$73%(w/w) of microbial additives, 62.73$\pm$4.54%(w/w) of initial moisture content and 55.32$\pm$3.14$^{\circ}C$ of fermentation temperature while those for SSFR using domestic animal bloods were obtained at 10.25$\pm$2.04%, 58.68$\pm$4.97% and 57.85$\pm$5.$65^{\circ}C$, respectively. Composting process in SSFR was initially proceeded through fermentation and solid materials were decomposed within 24 hours by maintaining higher moisture level, and maturing and drying steps are followed later. After the fermentation step, the concentrations of solid phase inorganic components were increased while that of organic components were decreased. Also, concentrations of total organic carbon(TOC), peptides, amino acids, polysaccharides, and low fatty acids in water extracts were increased. As fermentation in composting process depends on initial C/N ratios in water extracts of two samples were increased because of increased water-soluble TOC. From these results, it was revealed that solid state fermentation reactor using microbial additives can be used in composting process of organic wastes with broad C/N ratio.

• 한국토양비료학회지
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• 제44권2호
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• pp.221-227
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• 2011

논 토양에서 청보리, 자운영과 트리티케일을 시용하고 벼생육초기에 토양 미생물 생태계의 변화에 미치는 영향을 검토하였다. 녹비를 시용한 처리구는 관행에 비해 토양 유기물 함량은 유의적으로 증가하였으나 토양의 나트륨 함량은 유의적인 감소를 나타냈다. 내생균근균의 함량과 구성비율은 녹비 시용으로 관행 보다 유의적으로 높아졌으며 특히 청보리 처리구가 가장 높았다. 또한 토양의 그람음성 세균과 그람양성 세균의 비율과 불포화지방산과 포화지방산 함량의 비율은 청보리 처리구가 다른 처리구에 비해 유의적인 증가를 보였다. 그리고 주성분 분석에서 PC 1에 가장 큰 영향을 미친 미생물 군집은 그람음성 세균인 것으로 나타났으며 청보리 처리구는 관행과 가장 큰 차이를 나타냈다. 이러한 결과를 종합한 결과 청보리는 논 토양의 초기 미생물 다양성을 증대시킬 수 있는 최적의 녹비작물로 판단된다.

• KSBB Journal
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• 제16권6호
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• pp.579-591
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• 2001

The cell growth inhibitor effect of cervical cancer cells was investigated by liposome mediated transfection (pRcCMVp53/lipofectin) and by transfection using adenovirus (AdCMVp57). The papilloma virus cancer cell lines we used in this study were HPV16 positive, having inhibiter gene, wild p53 gene, CaSki, SiHa, HPV18 positive HeLa, HeLaS3 and HPV negative C33A, HT3. LacZ gene of E.coli was used as the marker gene for the transfection efficiency. The effect on the inhibition of tumor cell growth was measured by cell count and cell viability though ELISA analysis and MTT assay. The inhibition of tumor cell growth was confirmed by measuring each assay for six days, comparing with the normal control cell growth. The cell growth of cervical cancer calls by transfection was significantly reduced and showed tittle differences among the cell lines. To eliminate the potential problem of Ad(adenovirus) contamination during rAAV production, rAAV can be produced by a triple transfection of vector plasmic, packaging plasmid, and adenovirus helper plasmid. To examine the helper functions of Ad plasmids on the production of rAAV vector, we carried out cotransfection of three plasmids, AAV vector, packaging construct, and Ad helper plasmids. The optimized transfection condition for calcium phosphate method is 25ug of total DNA per 10-cm-diameter plate of 293 cell. We found that rAAV yields peaked at 48hr after Ad infection. The titer of rAAV was measured by the dot blot analysis to measure the number of particles/ml based on the quantification of viral DNA. Recent1y, Kombucha(fungi) was identified as a very potent antileukefic agent. In the present study, effect of natural toxin(plankton) and Kombucha is PSP(GTXI-3, neoSTX), on various MTT assay cervical cancer cell line. Toxin(GTX 1-3, neoSTX) also inhibited the proliferation in primary cervical cancer calls in a dose-dependent toxin concentration. These results showed that toxin was very potent in inhibiting the proliferation of cervical cancer calls in vitro. Toxins and Kombuoha exhibited a dose dependent inhibition of cellular proliferation in cancer cell line.

• 대한예방한의학회지
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• 제15권3호
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• pp.153-162
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• 2011

1. 서울, 경기소재 한의원에서 환약 10종과 경기소재 약국1곳에서 판매되는 한방환약 10종, 총 20종의 환약에 대해 미생물검출연구를 하였다. 2. 총세균수는 한의원환약, 약국환약에서 모두 WHO기준(1.0${\times}$107) 이내로 검출되었다. 3. 총진균수는 한의원환약, 약국환약의 각각 2종류, 1개제품에서 WHO기준(1.0${\times}$104)을 초과 하였다. 4. 배양 비의존적 방법을 이용하여 환약에 분포하는 Bacteria를 동정한 결과, 대부분의 박테리아는 토양에 존재하는 Firmicutes문, Proteobacteria문의 두 종류에 속하였다. 5. 환약의 안전성을 제고하기 위해, 생산, 가공, 유통, 보관 등 각 단계에서의 추가적인 미생물검출연구가 필요하다.