• Journal of Microbiology and Biotechnology
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• 제27권1호
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• pp.77-83
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• 2017

Lignocellulosic biomass represents a potentially large resource to supply the world's fuel and chemical feedstocks. Enzymatic bioconversion of this substrate offers a reliable strategy for accessing this material under mild reaction conditions. Owing to the complex nature of lignocellulose, many different enzymatic activities are required to function in concert to perform efficient transformation. In nature, large multienzyme complexes are known to effectively hydrolyze lignocellulose into constituent monomeric sugars. We created artificial complexes of enzymes, called rosettazymes, in order to hydrolyze glucuronoxylan, a common lignocellulose component, into its cognate sugar ${\small{D}}$-xylose and then further convert the ${\small{D}}$-xylose into ${\small{D}}$-xylonic acid, a Department of Energy top-30 platform chemical. Four different types of enzymes (endoxylanase, ${\alpha}$-glucuronidase, ${\beta}$-xylosidase, and xylose dehydrogenase) were incorporated into the artificial complexes. We demonstrated that tethering our enzymes in a complex resulted in significantly more activity (up to 71%) than the same amount of enzymes free in solution. We also determined that varying the enzyme composition affected the level of complex-related activity enhancement as well as overall yield.

• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.660-665
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• 2003

High-level expression of Thermus caldophilus GK24 alkaline phosphatase (Tca APase) was achieved in Escherichia coli using the pET-based expression plasmids, pEAP1 and pEAP2. In the case of plasmid pEAP2, the signal peptide region of Tca APase was replaced by the PelB leader peptide of expression vector pET-22b(+). Furthermore, the expression level was somewhat higher than that of plasmid pEAPl. A rapid purification procedure of Tca APase overproduced in E. coli was developed which involved heating to denature E. coli proteins followed by HiTrap Heparin HP column chromatography. Optimal temperature and pH and $Mg^{2+}$ dependence of the recombinant Tca APase were similar to those of native enzyme isolated from T. caldophilus GK24.

• 셀메드
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• 제2권2호
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• pp.18.1-18.16
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• 2012

An oncology-specific database called OncoRx (http://bit.ly/cancerRx) was previously set up in cyberspace to aid clinicians in identifying interactions of anticancer drugs (ACDs) and chemotherapy regimens with traditional Chinese medicines (TCMs) and complementary and alternative medicines (CAMs). Since then, users have requested the drug-CAM interactions (DCIs) of 5 specific CAMs (cranberry, melatonin, co-enzyme Q10, huachansu, reishi mushroom) to be updated in the database. Pharmacokinetic properties (metabolism, enzyme induction/inhibition, elimination), TCM properties and DCIs of each CAM were collated with 117 ACDs using 9 hardcopy compendia and online databases as resources. Additionally, individual ACDs and CAMs were used as keywords for PubMed searches in combination with the terms 'anticancer drugs', 'drug interactions', 'herb-drug/drug-herb interactions', 'pharmacokinetic interactions' and 'pharmacodynamic interactions'. DCI parameters consisted of interaction effects, evidence summaries, proposed management plans and alternative non-interacting CAMs, together with relevant citations and update dates of the DCIs. OncoRx is also used as a case to introduce the "Four Pharmaco-cybernetic Maxims" of quality, quantity, relationship and manner to developers of digital healthcare tools. Its role in Hayne's "5S" hierarchy of research evidence is also presented. OncoRx is meant to complement existing DCI resources for clinicians and alternative medicine practitioners as an additional drug information resource that provides evidence-based DCI information for ACD-CAM interactions.

• Natural Product Sciences
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• 제22권3호
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• pp.168-174
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• 2016

Anti-melanogenic effects of amaranth (AT), one of the key source of squalene, were investigated in melanocytes. Amaranth seed powder was extracted with water and melan-a cells were treated with various concentrations of AT. By using HPLC, content of myo-inositol, one of potential active components, was measured in the crude extract of AT.AT reduced the melanin content in melan-a melanocytes and down-regulated melanogenic enzyme activity such as tyrosinase, TRP-1 and TRP-2. By regulating melanogenic enzyme activity, AT may be a potential natural source for whitening agent. Myo-inositol was detected in AT by HPLC and may be one of the active compounds from AT involved in the regulation of anti-melanogenesis. In this study, we demonstrated that AT has anti-melanogenesis properties. This new function of amaranth may be useful in the development of new skin-whitening products and its value as food.

• 한국식품영양과학회지
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• 제27권1호
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• pp.46-50
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• 1998

폐단백질을 활용하는 방도의 하나로 폐단백질자원으로부터 토양에서 분리한 Aspergillus sp. 균주가 생산하는 phytase를 이용하여 불용성 단백질의 분리 효율성을 높였으며 추출 단백질의 기능성을 살펴보았다. 참깨박에 함유되어 있는 불용성 형태의 단백질을 가용성 형태의 단백질로 용출시키기 위한 최적 pH, 최적 온도, 최적 처리시간과 최적 첨가효소량은 4.0~5.0, $50^{\circ}C$, 8~10시간, 120unit였고, 효소처리된 참깨박은 phytase 처리의 경우 대조구에 비해 기포형성력은 크게 증가하지 않았으나 기포안정성은 다소 증가하였다. 참깨박 단백질의 유화력은 다소의 유화력과 안정성의 증가가 관찰되었고, 유지흡착력과 수분흡착력은 대조구에 비해서 높은 값을 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제29권8호
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• pp.1255-1265
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• 2019

To investigate the diversity of gastrointestinal microflora and lignocellulose-degrading enzymes in wild Asian elephants, three of these animals living in the same group were selected for study from the Wild Elephant Valley in the Xishuangbanna Nature Reserve of Yunnan Province, China. Fresh fecal samples from the three wild Asian elephants were analyzed by metagenomic sequencing to study the diversity of their gastrointestinal microbes and cellulolytic enzymes. There were a high abundance of Firmicutes and a higher abundance of hemicellulose-degrading hydrolases than cellulose-degrading hydrolases in the wild Asian elephants. Furthermore, there were a high abundance and a rich diversity of carbohydrate active enzymes (CAZymes) obtained from the gene set annotation of the three samples, with the majority of them showing low identity with the CAZy database entry. About half of the CAZymes had no species source at the phylum or genus level. These indicated that the wild Asian elephants might possess greater ability to digest hemicellulose than cellulose to provide energy, and moreover, the gastrointestinal tracts of these pachyderms might be a potential source of novel efficient lignocellulose-degrading enzymes. Therefore, the exploitation and utilization of these enzyme resources could help us to alleviate the current energy crisis and ensure food security.

• Journal of Microbiology and Biotechnology
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• 제33권10호
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• pp.1361-1369
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• 2023

Corynebacterium glutamicum (C. glutamicum) has been considered a very important and meaningful industrial microorganism for the production of amino acids worldwide. To produce amino acids, cells require nicotinamide adenine dinucleotide phosphate (NADPH), which is a biological reducing agent. The pentose phosphate pathway (PPP) can supply NADPH in cells via the 6-phosphogluconate dehydrogenase (6PGD) enzyme, which is an oxidoreductase that converts 6-phosphogluconate (6PG) to ribulose 5-phosphate (Ru5P), to produce NADPH. In this study, we identified the crystal structure of 6PGD_apo and 6PGD_NADP from C. glutamicum ATCC 13032 (Cg6PGD) and reported our biological research based on this structure. We identified the substrate binding site and co-factor binding site of Cg6PGD, which are crucial for understanding this enzyme. Based on the findings of our research, Cg6PGD is expected to be used as a NADPH resource in the food industry and as a drug target in the pharmaceutical industry.

• Journal of Microbiology and Biotechnology
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• 제24권7호
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• pp.943-953
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• 2014

The XylH gene (1,167-bp) encoding a novel hemicellulase (41,584 Da) was identified from the genome of Microbacterium trichothecenolyticum HY-17, a gastrointestinal bacterium of Gryllotalpa orientalis. The enzyme consisted of a single catalytic domain, which is 74% identical to that of an endo-${\beta}$-1,4-xylanase (GH10) from Isoptericola variabilis 225. Unlike other endo-${\beta}$-1,4-xylanases from invertebrate-symbiotic bacteria, rXylH was an alkali-tolerant multifunctional enzyme possessing endo-${\beta}$-1,4-xylanase activity together with ${\beta}$-1,3/${\beta}$-1,4-glucanase activity, which exhibited its highest xylanolytic activity at pH 9.0 and 60oC, and was relatively stable within a broad pH range of 5.0-10.0. The susceptibilities of different xylosebased polysaccharides to the XylH were assessed to be as follows: oat spelts xylan > beechwood xylan > birchwood xylan > wheat arabinoxylan. rXylH was also able to readily cleave p-nitrophenyl (pNP) cellobioside and pNP-xylopyranoside, but did not hydrolyze other pNP-sugar derivatives, xylobiose, or hexose-based materials. Enzymatic hydrolysis of birchwood xylan resulted in the product composition of xylobiose (71.2%) and xylotriose (28.8%) as end products.

• Food Science and Biotechnology
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• 제17권5호
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• pp.904-911
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• 2008

Covalent cross-links between a number of proteins and peptides explain why transglutaminase may be widely used by food processing industries. The objective of this work was optimization of the fermentation process to produce transglutaminase from a new microbial source, the Streptomyces sp. P20. The strategy adopted to modify the usual literature media was: (1) fractional factorial design (FFD) to elucidate the key medium ingredients, (2) central composite design (CCD) to optimise the concentration of the key components. Optimization of the medium resulted in not only an 86% increase in microbial transglutaminase activity as compared to the media cited in the literature, but also a reduction in the production cost. Optimal fermentation conditions - namely temperature and agitation rate - were also studied, using CCD methodology. Usual conditions of $30^{\circ}C$ and 100 rpm were within the optimal area. All other parameters for enzyme production were experimentally proven to be optimum fermentation conditions.

• 동의생리병리학회지
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• 제19권5호
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• pp.1386-1390
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• 2005

Lycii Fructus (LF) has been reported to possess various biological activities. In this study, we investigated the anti-inflammatory and anti-allergic effects of LF extract in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells and rat peritoneal mast cells(RPMC). LF extract inhibited NO production and the expressions of inducible NO synthase (iNOS) mRNA and enzyme protein, determined by Griess reactions, RT-PCR and Western blotting, respectively, in LPS-stimulated RAW 264.7 macrophages cells. LF extract significantly inhibited histamine release in compound48/80 stimulated rat peritoneal mast cells compared with the compound48/80 only treated cells. It is suggested that the LF extract can improve the inflammation status that involves the histamine release.