• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.3
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• pp.73-78
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• 2011

The pH is one of the most important factors affecting metabolism pathway and activity of hydrogen producing bacteria. The effect of operational pH on anaerobic hydrogen fermentation of food waste was evaluated at mesophilic condition. In this batch experiment, the initial pH was 8.0 and the operational pH was controlled at 4.7~7.0 by the addition of 5N KOH solutions. At the operational pH of 4.7, the lag phase and the maximum hydrogen production were 47.9h and 534.4 mL, respectively. The lag phase and the maximum hydrogen production were decreased as the operational pH increased. At the operational pH of 7.0, the lag phase and the maximum hydrogen production were 4.2 h and 213.8 mL, respectively.

• Land and Housing Review
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• v.12 no.2
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• pp.99-108
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• 2021

With increasing interest in living in hanoks, there's a growing need for more quantitative data on the thermal comfort performance of modern hanoks. With that in mind, this research project studied a modern hanok located in Jamjeong-Haetsal Village in Hwasun, Jeollanam Province as a case study to evaluate the Predicted Mean Vote (PMV) of modernized hanoks. Based on environmental data collected at the hanok and computer simulation both Life-Cycle PMV (L.C.PMV) and Normal PMV (N.PMV) were calculated for the hanok. Study results showed that during the summer and winter seasons the PMV and heat index at major heat and major cold weather points significantly deviated from the comfort zone. The rate of change in PMV was also greater in the winter than in the summer. The study found that the modern hanok lacks proper thermal insulation for maintaining thermal comfort.

• Food Engineering Progress
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• v.21 no.3
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• pp.286-291
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• 2017

This study was conducted to certify the effect of aqueous extracts from fifty medicinal plants on the activities of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in vitro. Each aqueous extract was prepared by combining one-part medicinal plants with twenty-parts distilled water at $80^{\circ}C$ for 8 h. Among the fifty medicinal plants, Allium sativum L. and Cinnamomum cassia Presl were regarded as an effective anti-hangover substance. Allium sativum L. extract increased ALDH activity more than 2 times compared with ADH activity, enhancing the acetaldehyde degradation. Cinnamomum cassia Presl extract dramatically inhibited ADH activity compared with ALDH activity, thus potently decreasing the acetaldehyde formation. ADH and ALDH activities were proportionally inhibited according to the increased concentration of Cinnamomum cassia Presl extract. The aqueous extract of Cinnamomum cassia Presl at a concentration of $45.33{\mu}g/mL$ inhibited ADH activity by 52.8% and ALDH activity by 11.0%.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.391-399
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• 2018

In this study, Diazinon which is the most widely used organophosphorus pesticides (OPPs) among pesticides was removed by ozone/hydrogen peroxide advanced oxidation process (Peroxone AOP). Diazinon is mainly found in groundwater, drinking water, rivers and ponds that are near agricultural areas using the pesticide. Accumulation of Diazinon on the body in the form of metabolites causes neurotoxicity, confusion, dizziness and vomiting. Diazinon is not easily removed by conventional water treatment processes. This study investigated the Diazinon removal characteristics with OH radicals with strong oxidizing power generated by using ozone and hydrogen peroxide. We determined optimal hydrogen peroxide/ozone injection molar ratio and confirmed the elimination reaction to initial Diazinon concentration, pH and DOC concentration, which are factors influencing the removal efficiency. Domestic researches on pesticide removal in the environment are much less than the cases of overseas. This study is expected to provide a basis for the process design for pesticide removal.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.413-420
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• 1988

The strain capable of growing on minimal medium containing aniline as a sole source of carbon was isolated from activated sludges and identified as Pseudomonas putida biotype A. The characterizations of the strain were determined. The optimum concentration for growth of the strain was 1-20 mM of aniline. No changes of pH were detected during cultivation. Some metabolic products of biodegradation of aniline were detected after cultivation of the strain on 10 mM aniline for 48 hours. The strain showed to be resistant to streptomycin, tetracycline, trimethoprim, and sulfanilamide. The strain was also capable of utilizing other aromatic compounds related to aniline as a sole source of carbon. One plasmid carried by this strain was detected. The properties of some of the mutant strains treated with mitomycin C were also discussed. The results suggest that separate, regulatory enzyme systems capable of degrading aniline may exist in plasmid DNA.

• Herbal Formula Science
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• v.31 no.4
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• pp.341-360
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• 2023

Background : To investigate the effect of Hwanggeumjackyak-tang (HJT) on Dextran sulfate sodium (DSS) induced ulcerative colitis. Methods : The experimental animals were divided into three groups; group 1, normal group(Normal); group 2, DSS-induced colitis and untreated group(UT+DSS); group 3, DSS-induced colitis and HJT 200 mg-treated group(HJT200+DSS). We evaluated cytotoxicity after HJT administration and confirmed the anti-inflammatory effect by histological changes in the intestine and genetic analysis of mucosal cells after HJT administration for each group. In addition, microbiological weapons and metabolites in faeces were examined, and the correlation between gut microbiome and metabolites was also investigated. Result : HJT was not observed to be cytotoxic, even at relatively high concentrations, and was effective in protecting the barrier and preventing intestinal inflammation by suppressing the increase in mucus secretion and the expression of inflammatory factors in mucosal cells. HJT treatment affected the increase in the amount and diversity of the gut microbiome in faeces and the increase in metabolites thought to be involved in alleviating inflammation in the gut. Conclusion : This study demonstrates the therapeutic potential of HJT in ulcerative colitis. Further studies should be carried out to confirm our findings.

• Microbiology and Biotechnology Letters
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• v.52 no.1
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• pp.102-104
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• 2024

Massilia sp. KACC 81254BP, isolated from a landfill on Jeju Island, Republic of Korea, possesses the capability to degrade polyhydroxyalkanoates (PHAs). The genomic analysis of strain KACC 81254BP consists of a circular chromosome comprising 5,028,452 base pairs with a DNA G+C content of 64.6%. This complete genome consists of a total of 4,513 genes, including those encoding the PHA degradation enzyme (PhaZ). This study offers valuable genomic insights into the enzymes responsible for degrading polyester plastics.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.458-465
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• 2021

Tubulysins are a group of bioactive secondary metabolites from myxobacteria exhibiting strong anticancer activity against various cancer cell lines. In this study, we describe the identification of putative tubulysin biosynthetic gene clusters (tubA~tubF) in the genome sequences of two tubulysin-producing myxobacterial strains, Archangium gephyra MEHO_002 and MEHO_004. The inactivation of the putative tubulysin biosynthetic genes resulted in a tubulysin-production defect. The DNA sequences of the A. gephyra MEHO_002 and MEHO_004 tubulysin biosynthetic genes were 97% identical, and the amino acid sequences of the encoded proteins shared a similarity of 97-100%. The nucleotide sequences of the tubulysin biosynthetic gene clusters in MEHO_002 and MEHO_004 were 86% identical to that in Cystobacter sp. SBCb004 known as a tubulysin-producing myxobacterium, and the organization of the clusters was identical except for the lack of a tubZ gene in the clusters in MEHO_002 and MEHO_004. The amino acid sequences of the proteins encoded by each gene were 88-97% similar to those encoded by SBCb004, and the domain compositions of the proteins were also identical.

• 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.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2002.04a
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• pp.69-75
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• 2002

Sterols play two major roles in plants: a bulk component in biological membranes and precursors of plant steroid hormones. Physiological effects of plant steroids, brassinosteroids (BRs), include cell elongation, cell division, stress tolerance, and senescence acceleration. Arabidopsis mutants that carry genetic defects in BR biosynthesis or its signaling display characteristic phenotypes, such as short robust inflorescences, dark-green round leaves, and sterility. Currently there are more than 100 dwarf mutants representing 7 genetic loci in Arabidopsis. Mutants of 6 loci, dwf1/dim1/cbb1, cpd/dwf3, dwf4, dwf5, det2/dwf6, dwf7 are rescued by exogenous application of BRs, whereas bri1/dwf2 shares phenotypes with the above 6 loci but are resistant to BRs. These suggest that the 6 loci are defective in BR biosynthesis, and the one locus is in BR signaling. Biochemical analyses, such as intermediate feeding tests, examining the levels of endogenous BR, and molecular cloning of the genes revealed that dwf7, dwf5, and dwf1 are defective in the three consecutive steps of sterol biosynthesis, from episterol to campesterol via 5-dehydroepisterol. Similarly, det2/dwf6, dwf4, and cpd/dwf3 were shown to be blocked in $D^4$ reduction, 22a-hydroxylation, and 23 a-hydroxylation, respectively. A signaling mutant bri1/dwf2 carries mutations in a Leucine-rich repeat receptor kinase. Interestingly, the bri1 mutant was shown to accumulate significant amount of BRs, suggesting that signaling and biosynthesis are dynamically coupled in Arabidopsis. Thus It is likely that transgenic plants over-expressing the rate-limiting step enzyme DWF4 as well as blocking its use by BRI1 could dramatically increase the biosynthetic yield of BRs. When applied industrially, BRs will boost new sector of plant biotechnology because of its potential use as a precursor of human steroid hormones, a novel lead compound for cholesterol-lowering effects, and a various application in plant protection.