• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.448-454
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• 2010

This study investigated the effect of PCE and TCE as electron acceptors on the bacterial composition of dechlorinating communities. The enrichment cultures reductively dechlorinating PCE and TCE were developed from three environment samples using acetate as electron donor. The cultures were prepared by sequential enrichment, which was seeded with sediment and dredged soil. Denatured gradient gel electrophresis (DGGE) of 16S rRNA gene fragment was used to compare the microbial communities of these three enrichment cultures. After incubation for 4 weeks, the removal efficiencies of PCE and TCE were highest from Yeocheon site (87.37% and 84.46%, respectively). PCE and TCE as electron acceptors affected the bacterial diversity and community profiles in the enrichment cultures. DGGE analysis showed that the dominant bacteria in PCE and TCE enrichment were belonged to Clostridium sp., Desulfotomaculum sp., and uncultured bacteria.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.1
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• pp.95-101
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• 2018

The epidermis which is stratified by epithelial tissue renewal based on keratinocyte differentiation protects the organism from various environmental insults by forming a physical barrier. Autophagy is a mechanism which mediates lysosomal delivery and degradation of protein aggregates, damaged organelles and intracellular microorganisms. Recent reports have shown that autophagy has critical roles for proper terminal differentiation to stratum corneum via removing metabolic organelles and nuclei. However, whether increasing autophagy can activate epidermal differentiation is unknown. Here, we screened a library of natural single compounds and discovered that betaine specifically increased the LC3 positive cytosolic punctate vesicles and LC3-I to LC3-II conversion in HaCaT human keratinocyte cell line, indicating increased autophagy flux. mTOR pathway, which negatively regulates autophagy, was not affected by betaine treatment, suggesting betaine-induced autophagy through an mTOR-independent pathway. Betaine-induced autophagy was also observed in primary human keratinocyte and skin equivalent. Furthermore, epidermal thickness was increased in skin equivalent under betaine treatment. Overall, our finding suggests that betaine as a novel regulator of autophagy may induce epidermal turnover and improve the skin barrier abnormality of the aged epidermis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.80-85
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• 2014

This study was focused on the development of fermented mushroom water extracts with antioxidative activities. Mushroom water extracts were fermented with Bifidobacterium bifidum, Lactobacillus plantarum, Lactobacillus acidophilus, Leuconostoc lactis, Streptococcus thermophilus and Lactobacillus sakei subsp. LI033 was isolated from kimchi. Fermented mushroom water extracts increased DPPH and ABTS radical scavenging activities in a dose-dependent manner. However, radical scavenging activity of fermented Phellinus linteus and Ganoderma lucidum water extracts was decreased compared to non-fermented mushroom water extracts. Antioxidative activity of fermented mushroom water extracts was also confirmed by xanthin oxidase (XO) inhibition and superoxide dismutase (SOD) activities at the same concentration. As the fermentation progressed, fermented mushroom water extracts increased XO inhibition activity and SOD activity. In conclusion, fermented mushroom water extracts were tentatively identified to enhance enzyme activity.

• Journal of the Korean Chemical Society
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• v.53 no.6
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• pp.653-662
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• 2009

Developing effective tools for predicting absorption, distribution, metabolism, excretion properties and toxicity (ADME/T) of new chemical entities in the early stage of drug design is one of the most important tasks in drug discovery and development today. As one of these attempts, support vector machines (SVM) has recently been exploited for the prediction of ADME/T related properties. However, two problems in SVM modeling, i.e. feature selection and parameters setting, are still far from solved. The two problems have been shown to be crucial to the efficiency and accuracy of SVM classification. In particular, the feature selection and optimal SVM parameters setting influence each other, which indicates that they should be dealt with simultaneously. In this account, we present an integrated practical solution, in which genetic-based algorithm (GA) is used for feature selection and grid search (GS) method for parameters optimization. hERG ion-channel inhibitor classification models of ADME/T related properties has been built for assessing and testing the proposed GA-GS-SVM. We generated 6 different models that are 3 different single models and 3 different ensemble models using training set - 1891 compounds and validated with external test set - 175 compounds. We compared single model with ensemble model to solve data imbalance problems. It was able to improve accuracy of prediction to use ensemble model.

• Journal of Life Science
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• v.20 no.7
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• pp.969-976
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• 2010

In vivo studies of KR-31125 (2-butyl-5-dimethoxymethyl-6-phenyl-7-methyl-3-[[2'-(1H-tetrazol-5-yl) biphenyl-4-yl]methyl]-3H-imidazo[4,5-b]pyridine) were performed in pithed rats, conscious angiotensin II (AII) challenged normotensive rats, renal hypertensive rats (RHRs) and furosemide-treated beagle dogs. KR-31125 induced a non-parallel right shift in the dose-pressor response curve to AII ($ID_{50}$: 0.095 mg/kg) with a dose-dependent reduction in the maximum responses in pithed rats. Compared to losartan, this antagonistic effect was about 18 times more potent, presenting competitive antagonism. Other agonists such as norepinephrine and vasopressin did not alter the responses induced by KR-31125. Orally administered KR-31125 had no agonistic effect and dose-dependently inhibited the pressor response to AII with a slightly weaker potency ($ID_{50}$: 0.25 and 0.47 mg/kg, respectively) in the AII-challenged normotensive rat model, but with a more rapid onset of action than losartan (time to $E_{max}$: 30 min for KR-31125 and 6 hr for losartan). KR-31125 produced a dose-dependent antihypertensive effect with a higher potency than losartan in RHRs, and these effects were confirmed in furosemide-treated dogs where they presented a dose-dependent and long-lasting (>8 hr) antihypertensive effect with a rapid onset of action (time to $E_{max}$: 2-4 hr), as well as a 20-fold greater potency than losartan. These results suggest that KR-31125 is a potent, orally active $AT_1$ receptor antagonist that can be applied to the development of new diagnostic and research tools as an added exploratory potential of $AT_1$ receptor antagonist.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.290-303
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• 2003

Modern agriculture has been heavily dependent on chemical fertilizers to meet the food demands of ever increasing population. Progressive depletion of major plant nutrients in soil due to intensive cultivation practices has also necessitated the use of higher dose of chemical fertilizers particularly in soils where the organic matter content is very low. Indiscriminate use of chemical fertilizers and pressure on agriculturists to enhance per area crop yields has led to fast depletion of fossil fuel resources with concomitant increase in the prices of chemical fertilizers and also led to environmental pollution. Hence, the current trend throughout the world is to explore the possibility of using alternate nutrient sources or increasing the efficiency of chemical fertilizers by supplementing them with organic fertilizers and bioinoculants comprising largely microbes like, bacteria, fungi, algae etc to enhance nitrogen and phosphates in the soil thus creating a sustainable agricultural environment. Among the different microbial inoculants or biofertilizers, Azospirillum could be a potential candidate due to its non specific host root colonization. It had the capability to fix $N_2$ in wide pH regimes and even in presence of combined nitrogen. Azospirillum inoculation can increase the crop yield to 10-25% and substitute 25% of recommended doses of nitrogenous fertilizers. Apart from nitrogen fixation, Azospirillum is also involved in the root improvement, the activity which was attributed to an increase in the rate of water and mineral uptake by roots. The ability of Azospirillum to produce phytohormones was reported to enhance the root respiration rate, metabolism and root proliferation. They have also been reported to produce polyhydroxybutyrate, that can be used as a biodegradable thermosplastic. A lot of studies have addressed improvements in enhancing its efficiency to fix nitrogen fixation and hormone production.

• Journal of Life Science
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• v.29 no.1
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• pp.37-44
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• 2019

Leaves of Sasa quelpaertensis Nakai are used in folk medicine for their anti-inflammatory, antipyretic, and diuretic properties. To ensure efficient utilization of S. quelpaertensis leaf, we previously reported a preparation method for phytochemical-rich extract (PRE) using the leaf residue, which was produced after hot water extraction. This study was undertaken to evaluate the hypouricemic potential of S. quelpaertensis leaf PRE in potassium oxonate (PO)-induced hyperuricemic mice. The administration of PRE significantly reduced serum uric acid (UA), blood urea nitrogen (BUN), and serum creatinine levels and increased urine UA and creatinine levels in the PO-induced hyperuricemic mice. It also reduced liver UA levels and xanthine oxidase (XA) activity. A histological analysis revealed that PRE administration protected against PO-induced liver damage, pointing to anti-inflammatory and cytoprotective effects in PO-induced hyperuricemic mice. We analyzed the transcriptome response to PRE administration in PO-induced hyperuricemic mice using RNA sequencing (RNA-Seq) in kidney tissues. The administration of PRE mainly enriched genes involved in mediating immune and inflammatory responses and the metabolic pathway. A Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the metabolic pathway, purine metabolism, and antibody biosynthesis were the major pathways altered in the PRE and PO groups. These results suggest a potential role for PRE in the prevention and treatment of hyperuricemia with inflammation.

• Journal of Life Science
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• v.29 no.11
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• pp.1281-1293
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• 2019

The rhizosphere is the active zone where plant roots communicate with the soil microbiome, each responding to the other's signals. The soil microbiome within the rhizosphere that is beneficial to plant growth and productivity is known as plant growth-promoting rhizobacteria (PGPR). PGPR take part in many pivotal plant processes, including plant growth, development, immunity, and productivity, by influencing acquisition and utilization of nutrient molecules, regulation of phytohormone biosynthesis, signaling, and response, and resistance to biotic- and abiotic-stresses. PGPR also produce secondary compounds and volatile organic compounds (VOCs) that elicit plant growth. Moreover, plant roots exude attractants that cause PGPR to aggregate in the rhizosphere zone for colonization, improving soil properties and protecting plants against pathogenic factors. The interactions between PGPR and plant roots in rhizosphere are essential and interdependent. Many studies have reported that PGPR function in multiple ways under the same or diverse conditions, directly and indirectly. This review focuses on the roles and strategies of PGPR in enhancing nutrient acquisition by nutrient fixation/solubilization/mineralization, inducing plant growth regulators/phytohormones, and promoting growth and development of root and shoot by affecting cell division, elongation, and differentiation. We also summarize the current knowledge of the effects of PGPR and the soil microbiota on plants.

• Journal of Life Science
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• v.31 no.11
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• pp.1046-1055
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• 2021

Vanillin is the primary flavor and fragrance compound of natural vanilla and is extensively used in the food, beverage, perfumery, pharmaceutical industries, and other applications. Vanillin can be produced by chemical synthesis, extraction from vanilla plants, microbial bioconversion of natural precursors to vanillin, and direct fermentation using glucose. Currently, most commercially available vanillin is produced by extraction from cured vanilla pods and by chemical synthesis using guaiacol and glyoxylic acid as starting raw materials. Due to environmental issues, health complaints, preference for natural sources, and the limited supply and soaring price of natural vanilla, biotechnology-based vanillin production is regarded as a promising alternative. As many microorganisms that are able to metabolize several natural precursors, including ferulic acid, eugenol, isoeugenol, and lignin, and accumulate vanillin, have been screened and evaluated, myriad strategies and efforts have been employed for the development of commercially viable production technology. This review outlines the recent advances in the biotechnological production of natural vanillin with the use of these natural precursors. Moreover, it highlights the recent engineering approaches for the production of natural vanillin from renewable carbon sources based on the de novo biosynthetic pathway of vanillin from glucose, together with appropriate solution strategies to overcome the challenges posed to increase production titers.

• Journal of Life Science
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• v.32 no.10
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• pp.762-770
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• 2022

Hyperglycemia in type 2 diabetes can be alleviated by promoting cellular glucose uptake. Betulinic acid (3β,-3-hydroxy-lup-20(29)-en-28-oic acid) is a pentacyclic lupane-type triterpenoid compound. Although there have been studies on the antidiabetic activity of betulinic acid, studies on cellular glucose uptake are lacking. We investigated the effects of betulinic acid on glucose uptake and its mechanism of action in 3T3-L1 adipocytes. Betulinic acid significantly stimulated glucose uptake in 3T3-L1 adipocytes by increasing the phosphorylation of the insulin receptor substrate 1-tyrosine (IRS-1tyr) in the insulin signaling pathway, which in turn stimulated the activation of phosphoinositide 3-kinase (PI3K) and the phosphorylation of protein kinase B (Akt). The activation of PI3K and Akt by betulinic acid translocated glucose transporter 4 to the plasma membrane (PM-GLUT4), thereby increasing the expression of PM-GLUT4 and thus stimulating cellular glucose uptake. Betulinic acid also significantly increased the phosphorylation/activation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase. The activation of PI3K and AMPK by betulinic acid was confirmed using the PI3K inhibitor wortmannin and the AMPK inhibitor compound C. The increase in glucose uptake induced by betulinic acid was significantly decreased by wortmannin and compound C in the 3T3-L1 adipocytes. These results suggest that betulinic acid stimulates glucose uptake by activating PI3K and AMPK in 3T3-L1 adipocytes.