• Genomics & Informatics
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• 제11권3호
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• pp.114-120
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• 2013

The microbial diversity in soil ecosystems is higher than in any other microbial ecosystem. The majority of soil microorganisms has not been characterized, because the dominant members have not been readily culturable on standard cultivation media; therefore, the soil ecosystem is a great reservoir for the discovery of novel microbial enzymes and bioactivities. The soil metagenome, the collective microbial genome, could be cloned and sequenced directly from soils to search for novel microbial resources. This review summarizes the microbial diversity in soils and the efforts to search for microbial resources from the soil metagenome, with more emphasis on the potential of bioprospecting metagenomics and recent discoveries.

• Journal of Microbiology and Biotechnology
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• 제29권5호
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• pp.731-738
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• 2019

Endophytic fungi are an important component of plant microbiota, and have the excellent capacity for producing a broad variety of bioactive metabolites. These bioactive metabolites not only affect the survival of the host plant, but also provide valuable lead compounds for novel drug discovery. In this study, forty-two endophytic filamentous fungi were isolated from Ficus elastica leaves, and further identified as seven individual taxa by ITS-rDNA sequencing. The antimicrobial activity of these endophytic fungi was evaluated against five pathogenic microorganisms. Two strains, Fes1711 (Penicillium funiculosum) and Fes1712 (Trichoderma harzianum), displayed broad-spectrum bioactivities. Our following study emphasizes the isolation, identification and bioactivity testing of chemical metabolites produced by T. harzianum Fes1712. Two new isocoumarin derivatives (1 and 2), together with three known compounds (3-5) were isolated, and their structures were elucidated using NMR and MS. Compounds 1 and 2 exhibited inhibitory activity against Escherichia coli. Our findings reveal that endophytic fungi from the rubber tree F. elastica leaves exhibit unique characteristics and are potential producers of novel natural bioactive products.

• 한국미생물·생명공학회지
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• 제46권1호
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• pp.9-17
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• 2018

The aims of this work were to characterize and determine bioactivities of crude exopolysaccharide (EPS) extract from Bacillus tequilensis PS21 isolated from milk kefir from Kampaeng Petch, Thailand. B. tequilensis PS21 produced 112.1 mg dried EPS/l from initial 80 g/l lactose in modified TSB media at 52 h, with EPS product yield of 8.9 mg EPS/g lactose and specific product yield of 0.3 mg EPS/mg biomass. The FTIR result confirmed EPS to be a protein-bound polysaccharide and SEM analysis showed the morphology to be a grainy appearance with an uneven surface, covered with pores. HPLC analysis determined EPS as a heteropolysaccharide consisting of five sugar units with the following molar ratios; xylose (17.65), glucose (2.54), ribose (1.83), rhamnose (1.23), and galactose (1). Chemical components of this EPS were predominantly carbohydrate at 697.8 mg/g EPS (65%), protein 361.4 mg/g EPS (34%), and nucleic acid 12.5 mg/g EPS (1%). The EPS demonstrated antioxidant activities at 57.5% DPPH scavenging activity, $37.2{\mu}M\;Fe(II)/mg$ EPS and $34.9{\mu}M\;TEAC\;{\mu}M/mg$ EPS using DPPH, FRAP and ABTS assays, respectively. EPS also exhibited anti-tyrosinase activity at 34.9% inhibition. This work represents the first finding of EPS produced by Bacillus sp. from Thai milk kefir which shows potential applications in the production of antioxidant functional foods and whitening cosmetics. However, optimization of EPS production for industrial exploitation requires further study to ascertain the economic potential.

• KSBB Journal
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• 제26권2호
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• pp.93-99
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• 2011

Glycosylation is a key mechanism in determining diversity of natural products, and influencing their bioactivities. This approach requires a core set of glycosyltransferase that synthesizes the diverse sugar structures observed in nature. Recently, the researchers have begun to alter the sugar moiety and glycosylation patterns of natural products both in vivo E. coli system and in vitro for their glycodiversification. This review highlights new glycosylation tools using microbialproduced deoxysugar and a flexible glycosyltransferase on natural plant-flavonoids to generate novel glycoforms with useful biological activity.

• 생명과학회지
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• 제31권4호
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• pp.430-441
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• 2021

세스퀴테르펜 락톤(Sesquiterpene lactones; STL) 화합물은 테르페노이드의 일종으로 주로 국화과에서 발견이 되고 강한 세포 독성을 나타내는 생리학적 특성을 지니고 있다. 이러한 세스퀴테르펜 락톤은 강한 세포 독성으로 인해 연구가 미미하였으나, 최근 화학적 변형을 통해 독성이 적은 형태로 합성하여 새로운 의약품 개발로서의 연구가 활발히 진행되고 있다. 세스퀴테르펜 락톤 화합물인 artemisinin 및 mipsagargin 화합물은 현재 말라리아 및 종양성장에 대한 약물로 사용되고 있다. 또한 항산화, 간보호, 항바이러스, 항균, 항종양 및 항노화 등의 생리활성 효능이 보고되어 있으며, 종양세포에서 자멸사를 유도하여 항암제로서의 연구가 진행되고 있다. 본 연구에서는 세스퀴테르펜 락톤 화합물인 artemisinin, costunolide, thapsigargin, arglabin, parthenolide, alantolactone, cynaropicrin, helenalin, 및 santonin의 생리활성 효능에 대한 연구 동향을 검토하고자 한다.

• 생명과학회지
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• 제29권2호
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• pp.164-172
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• 2019

국내 표고버섯은 참나무 톱밥을 주 원료로 한 인공배지를 이용하여 재배하고 있으며, 표고버섯 재배 후 부산물로 발생하는 [수확 후 배지](Spent Mushroom Substrate: SMS)는 약 50,000톤으로 추정된다. 본 연구에서는 별도의 용도 없이 폐기되고 있는 표고버섯 SMS를 유용 생물자원으로 이용하기 위해, 1회 수확 후 SMS 및 3회 수확 후 SMS의 열수 추출물을 조제하여 이들의 항산화, 항균, 항당뇨, 항응고 및 혈소판 응집저해활성을 평가하였다. 대조구로는 재배용 살균배지 및 표고버섯의 열수 추출물을 이용하였다. 그 결과, 표고버섯 SMS 추출물은 표고버섯 및 살균배지 추출물보다 우수한 DPPH 음이온, ABTS 양이온 nitrite 소거능 및 환원력을 나타내었다. 1회 및 3회 SMS 추출물들은 0.5 mg/disc 농도에서는 사용된 세균 및 진균에 대한 항균력이 나타나지 않았으나, 0.5 mg/ml 농도에서 우수한 ${\alpha}$-glucosidase 저해활성을 나타내었다. 또한 thrombin time, prothrombin time, activated partial thromboplastin time 및 혈소판 응집저해 활성 측정 결과, SMS 추출물들은 혈소판 응집에는 미미한 영향을 나타내었으나, 강력한 혈액응고저해 활성을 나타내어 항혈전 조성물로 개발 가능함을 확인하였다. 본 연구결과는 SMS를 폐기 대상이 아닌, 표고버섯 균사체가 대량 배양된 생물자원으로 고려하는 것이 필요함을 제시하며, SMS를 이용한 항산화, 항당뇨, 항혈전 조성물 개발이 가능함을 제시하고 있다.

• Biomolecules & Therapeutics
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• 제28권3호
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• pp.240-249
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• 2020

Despite the therapeutic effect of mesenchymal stem cells (MSCs) in ischemic diseases, pathophysiological conditions, including hypoxia, limited nutrient availability, and oxidative stress restrict their potential. To address this issue, we investigated the effect of melatonin on the bioactivities of MSCs. Treatment of MSCs with melatonin increased the expression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α). Melatonin treatment enhanced mitochondrial oxidative phosphorylation in MSCs in a PGC-1α-dependent manner. Melatonin-mediated PGC-1α expression enhanced the proliferative potential of MSCs through regulation of cell cycle-associated protein activity. In addition, melatonin promoted the angiogenic ability of MSCs, including migration and invasion abilities and secretion of angiogenic cytokines by increasing PGC-1α expression. In a murine hindlimb ischemia model, the survival of transplanted melatonin-treated MSCs was significantly increased in the ischemic tissues, resulting in improvement of functional recovery, such as blood perfusion, limb salvage, neovascularization, and protection against necrosis and fibrosis. These findings indicate that the therapeutic effect of melatonin-treated MSCs in ischemic diseases is mediated via regulation of PGC-1α level. This study suggests that melatonin-induced PGC-1α might serve as a novel target for MSC-based therapy of ischemic diseases, and melatonin-treated MSCs could be used as an effective cell-based therapeutic option for patients with ischemic diseases.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1319-1327
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• 2009

Marine red algae of genus Laurencia are becoming the most important resources to produce unique natural metabolites with wide bioactivities. However, reports related to Laurencia undulata, an edible species used as folk herb, are rarely found to date. In this research, 5-hydroxymethyl-2-furfural (5-HMF) was isolated and characterized by nuclear magnetic resonance (NMR) from Laurencia undulata as well as other marine algae. The following characteristics of 5-HMF were systematically evaluated: its antioxidant activities, such as typical free-radicals scavenging in vitro by electron spin resonance spectrometry (ESR) and intracellular reactive oxygen species (ROS) scavenging; membrane protein oxidation; oxidative enzyme myeloperoxidase (MPO) inhibition; as well as expressions of antioxidative enzymes glutathione (GSH) and superoxide dismutase (SOD) on the gene level using the polymerase chain reaction (PCR) method. The results demonstrated that 5-HMF could be developed as a novel marine natural antioxidant or potential precursor for practical applications in the food, cosmetic, and pharmaceutical fields.

• Journal of Microbiology and Biotechnology
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• 제32권9호
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• pp.1146-1153
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• 2022

Many probiotic species have been used as a fermentation starter for manufacturing functional food materials. We have isolated Bifidobacterium animalis subsp. lactis LDTM 8102 from the feces of infants as a novel strain for fermentation. While Glycine max has been known to display various bioactivities including anti-oxidant, anti-skin aging, and anti-cancer effects, the immune-modulatory effect of Glycine max has not been reported. In the current study, we have discovered that the extract of Glycine max fermented with B. animalis subsp. lactis LDTM 8102 (GFB 8102), could exert immuno-modulatory properties. GFB 8102 treatment increased the production of immune-stimulatory cytokines in RAW264.7 macrophages without any noticeable cytotoxicity. Analysis of the molecular mechanism revealed that GFB 8102 could upregulate MAPK2K and MAPK signaling pathways including ERK, p38, and JNK. GFB 8102 also increased the proliferation rate of splenocytes isolated from mice. In an animal study, administration of GFB 8102 partially recovered cyclophosphamide-mediated reduction in thymus and spleen weight. Moreover, splenocytes from the GFB 8102-treated group exhibited increased TNF-α, IL-6, and IL-1β production. Based on these findings, GFB 8102 could be a promising functional food material for enhancing immune function.

• Biomolecules & Therapeutics
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• 제24권3호
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• pp.260-267
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• 2016

Mesenchymal stem cells (MSCs) offer significant therapeutic promise for various regenerative therapies. However, MSC-based therapy for injury exhibits low efficacy due to the pathological environment in target tissues and the differences between in vitro and in vivo conditions. To address this issue, we developed adipose-derived MSC spheroids as a novel delivery method to preserve the stem cell microenvironment. MSC spheroids were generated by suspension culture for 3 days, and their sizes increased in a time-dependent manner. After re-attachment of MSC spheroids to the plastic dish, their adhesion capacity and morphology were not altered. MSC spheroids showed enhanced production of hypoxia-induced angiogenic cytokines such as vascular endothelial growth factor (VEGF), stromal cell derived factor (SDF), and hepatocyte growth factor (HGF). In addition, spheroid culture promoted the preservation of extracellular matrix (ECM) components, such as laminin and fibronectin, in a culture time- and spheroid size-dependent manner. Furthermore, phosphorylation of AKT, a cell survival signal, was significantly higher and the expression of pro-apoptotic molecules, poly (ADP ribose) polymerase-1 (PARP-1) and cleaved caspase-3, was markedly lower in the spheroids than in MSCs in monolayers. In the murine hindlimb ischemia model, transplanted MSC spheroids showed better proliferation than MSCs in monolayer. These findings suggest that MSC spheroids promote MSC bioactivities via secretion of angiogenic cytokines, preservation of ECM components, and regulation of apoptotic signals. Therefore, MSC spheroid-based cell therapy may serve as a simple and effective strategy for regenerative medicine.