• BMB Reports
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• 제38권5호
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• pp.609-618
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• 2005

$\gamma$-Glutamyl transpeptidase (GGT, EC 2.3.2.2.) catalyzes the transfer of the $\gamma$-glutamyl moiety from $\gamma$-glutamyl containing ompounds, notably glutathione (GSH), to acceptor amino acids and peptides. A second gene (GGTII) encoding GGT was previously isolated and characterized from the fission yeast Schizosaccharomyces pombe. In the present work, the GGTII-lacZ fusion gene was constructed and used to study the transcriptional regulation of the S. pombe GGTII gene. The synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene was significantly enhanced by NO-generating SNP and hydrogen peroxide in the wild type yeast cells. The GGTII mRNA level was increased in the wild-type S. pombe cells treated with SNP. However, the induction by SNP was abolished in the Pap1-negative S. pombe cells, implying that the induction by SNP of GGTII is mediated by Pap1. Fermentable carbon sources, such as glucose (at low concentrations), lactose and sucrose, as a sole carbon source, enhanced the synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene in wild type KP1 cells but not in Pap1-negative cells. Glycerol, a non-fermentable carbon source, was also able to induce the synthesis of $\beta$-galactosidase from the fusion gene, but other non-fermentable carbon sources such as acetate and ethanol were not. Transcriptional induction of the GGTII gene by fermentable carbon sources was also confirmed by increased GGTII mRNA levels in the yeast cells grown with them. Nitrogen starvation was also able to induce the synthesis of $\beta$-galactosidase from the GGTII-lacZ fusion gene in a Pap1-dependent manner. On the basis of the results, it is concluded that the S. pombe GGTII gene is regulated by oxidative and metabolic stress.

• Molecules and Cells
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• 제20권1호
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• pp.74-82
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• 2005

Glutaredoxins (Grxs) are thioloxidoreductases which are required for maintaining thiol/disulfide equilibrium in living cells. The Grx3 gene, which encodes one of the three monothiol Grxs in the fission yeast Schizosaccharomyces pombe, was characterized, and its transcriptional regulation studied. Genomic DNA encoding Grx3 was isolated by PCR, and a plasmid pTT3 carrying this DNA was produced. The DNA sequence has 1,267 bp, which would encode a monothiol Grx of 166 amino acids with a molecular mass of 18.3 kDa. The putative protein has 27% homology with Grx5, and contains many hydrophobic amino acid residues in its N-terminal region. S. pombe cells harboring pTT3 had increased Grx activity and enhanced survival on minimal medium plates containing aluminum (5 mM), BSO (0.05 mM), menadione (0.01 mM) or cadmium (0.2 mM). The 568 bp upstream region of Grx3 was fused into the promoterless b-galactosidase gene of the shuttle vector YEp367R to generate fusion plasmid pMJS10. Potassium chloride (KCl) and metals including aluminum and cadmium enhanced the synthesis of ${\beta}$-galactosidase from the fusion gene. The synthesis of ${\beta}$-galactosidase was also enhanced, in a Pap1-dependent manner, by fermentable carbon sources such as glucose (at low concentrations) and sucrose, but not by non-fermentable carbon sources such as ethanol and acetate. Grx3 mRNA increased in response to treatment with BSO. These observations indicate that S. pombe Grx3 is involved in the response to stress, and is regulated by stress.

• 동아시아식생활학회지
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• 제23권5호
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• pp.546-560
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• 2013

In this study, a natural fermentation starter formulation was developed for manufacturing Korean bread products by substituting baker's yeast with naturally fermented blueberry starters. As the incubation time of the blueberry extracts increased, the pH and total titratable acidity increased. The sweetness (brix%) of blueberry extracts containing various amounts of sugar were higher than the other sample. The result of alcoholicity for naturally fermented blueberry extracts, the fermented blueberry extract containing 20% sugar was highest. Lactic acid bacteria counts increased until the 4th day; however, it decreased from the 5th day, and viable yeast counts increased consistently until the 5th day. The volume for naturally fermented blueberry extracts increased as the incubation time increased. As the fermentation time of blueberry starters increased, the pH of bread dough decreased. The RVA analysis conveyed that wheat flour retrogradation was retarded by increasing the blueberry starter content. The weight of pan breads containing blueberry starters were higher than that of the control, while the volume, specific volume and baking loss rate were lower than those of the control. The moisture content of pan breads containing blueberry starter decreased as storage time increased. In analyzing the visible mold colony during 7 days of storage at $28^{\circ}C$, mold growth in pan breads containing the blueberry starter was retarded. The hardness of breads containing blueberry starters were significantly increased as storage time increased. The breads containing 50% naturally fermented blueberry starter have acceptable sensory properties. In conclusion, these results indicated that 50% of natural fermentation blueberry starter could be very useful as a substitute for yeast when making naturally fermented bread.

• BMB Reports
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• 제41권6호
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• pp.448-454
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• 2008

Two full-length cDNAs, PutPMP3-1 and PutPMP3-2, encoding PMP3 family proteins were isolated from Puccinellia tenuiflora, a monocotyledonous halophyte. Expression of both genes was induced by low temperature, salt stress, dehydration, ABA, and $NaHCO_3$. Transcripts of PutPMP3-2 were more strongly induced by these stresses relative to those of PutPMP3-1, particularly under low temperature and dehydration conditions. Expression of PutPMP3-1 and PutPMP3-2 in yeast mutants lacking the PMP3 gene can functionally complement the membrane hyper-polarization and salt sensitivity phenotypes resulting from PMP3 deletion. To compare the functions of PutPMP3-1 and PutPMP3-2, the orthologous genes in rice (OsLti6a and OsLti6b) were isolated. Both OsLti6a and OsLti6b could functionally complement the loss of PMP3 in yeast. PutPMP3-2 and OsLti6a were more effective in reversing membrane hyperpolarization than PutPMP3-1 and OsLti6b. However, the four yeast transformants each showed similar levels of salt tolerance. These results imply that these PMP3 family members don't function identically under different stress tolerance conditions.

• Journal of Microbiology and Biotechnology
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• 제14권2호
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• pp.237-242
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• 2004

Cell growth and the production of pullulan by Aureobasidium pullulan HP-2001, the UV-induced mutant of A pullulans ATCC 42023, increased with increased concentration of glucose up to 15.0% (w/v). Maximal production of pullulan in the flask scale was 27.65 g/l, when concentrations of glucose and yeast extract were 15.0 and 0.25% (w/v), respectively. Maximal conversion rate of pullulan from glucose as the carbon source was 0.37, when those of glucose and yeast extract were 5.0 and 0.15% (w/v), respectively. On the basis of total amount of pullulan, the conversion rate of pullulan from glucose, and utilization rate of glucose to cell mass and pullulan by A. pullulans HP-2001, the optimal concentrations of glucose and yeast extract for the mass production of pullulan were determined to be 10.0 and 0.25% (w/v), respectively, at which concentrations the production of pullulan and its conversion rate were 27.14 g/l and 0.27, respectively. Maximal production of pullulan with optimized concentrations of carbon and nitrogen sources by A. pullulans HP-200l in a 7-1 bioreactor was 32.12 g/l for 72 h culture, and that in a 100-1 bioreactor with the inner pressure of $0.4 kgf/cm^2$ was 36.87 g/l. Increased inner pressure of a 100-1 bioreactor resulted in a higher concentration of dissolved oxygen in the medium, which might enhance the production of pullulan by A. pullulans HP-2001.

• 한국균학회지
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• 제48권2호
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• pp.161-167
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• 2020

국내에 자생하는 지렁이로(붉은줄지렁이)의 장에서 야생효모를 분리, 동정하고자 하였다. 지렁이는 고양시 난지 물 재생 센터에서 분양 받았으며, 지렁이 5마리에서 19개의 야생효모를 분리하였다. 효모의 D1/D2 영역으로 동정하여 국내에 보고되지 않은 효모 3균주를 선별하였다. 국내 미기록종 효모인 Yarrowia deformans YP242 (=KACC48778), Sporidiobolus pararoseus YP66(=KCTC27963), Naganishia liquefaciens YI9 (=KACC48948) 균주는 위상차현미경, API 20C AUX kit를 통해 균학적 특성을 조사하였다. YP242, YI9, YP66 균주의 세포 모양은 타원형이며, 집락은 볼록하고, 부드러운 재질을 가지는 것으로 관찰되었다. 탄소원 활성 측정 결과, YP242는 glycerol, L-arabinose, N-acetyl-D-glucosamine을, YP66는 N-acetyl-D-glucosamine을, liquefaciens YI9는 2-keto-D-gluconate을 탄소원으로 사용할 수 있음을 확인하였다.

• Mycobiology
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• 제49권5호
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• pp.469-475
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• 2021

Three strains, YP416^T, YP421^T, and Y422, were isolated from soil samples in Pocheon City, Gyeonggi province, South Korea. The strains belong to two novel yeast species in the genus Mrakia. Molecular phylogenetic analysis showed that the strain YP416^T was closely related to Mrakia niccombsii. Still, it differed by 9 nucleotide substitutions with no gap (1.51%) in the D1/D2 domain of the LSU rRNA gene and 14 nucleotide substitutions with 7 gaps (2.36%) in the ITS region. The strain YP421^T differed from the type strain of the most closely related species, Mrakia aquatica, by 5 nucleotide substitutions with no gap (0.81%) in the D1/D2 domain of the LSU rRNA gene and 9 nucleotide substitutions with one gap (1.43%) in the ITS region. The names Mrakia terrae sp. nov. and Mrakia soli sp. nov. are proposed, with type strains YP416^T (KCTC 27886^T) and YP421^T (KCTC 27890^T), respectively. MycoBank numbers of the strains YP416^T and YP421^T are MB 836844 and MB 836847, respectively.

• Advances in Traditional Medicine
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• 제8권3호
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• pp.252-259
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• 2008

The chloroform extract of Croton roxburghii (Family: Euphorbiaceae) was evaluated for its antipyretic effects in Brewer's yeast induced hyperthermia in rats. The anti-inflammatory effect of the Croton roxburghii was also evaluated by using carrageenan, dextran, histamine, serotonin induced rat paw oedema and cotton pellet induced granuloma (chronic) models in rats. The chloroform extract of Croton roxburghii (CECR) exhibited significant anti-pyretic and anti-inflammatory effect at the dose 50, 100 and 200 mg/kg. Maximum inhibition (55.32%) was notedat the dose of 200 mg/kg after 3 h of drug treatment in carrageenan induced paw oedema, whereas the Indomethacin (standard drug) produced 61.33% of inhibition. The extract exhibited significant anti-inflammatory activity in dextran induced paw edema in a dose dependent manner. In the chronic model (cotton pellet induced granuloma) the CECR (200 mg/kg) and Indomethacin (10 mg/kg) showed decreased formation of granuloma tissue by 52.32% and 56.32% respectively. The extract also exhibited a significant antipyretic response in Brewer's yeast induced pyrexia in rats. Thus, the present study revealed that the CECR exhibited significant antipyretic and anti-inflammatory activity in the tested animal models.

• 한국식품과학회지
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• 제47권5호
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• pp.615-622
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• 2015

The objectives of this study were to evaluate the sensory properties of various natural flavor enhancers (NFEs) and to understand the effects of NaCl and temperature on the sensory characteristics of these NFEs. Descriptive analysis was conducted to evaluate six types of NFEs: yeast extract-based NFE, three; fish sauce-based NFE, one; soy sauce-based NFE, one; and hydrolyzed peptide NFE-based, one. The effects of NaCl (no addition vs. addition) and temperature ($20^{\circ}C$ vs. $55^{\circ}C$) were also evaluated. The results showed that the overall flavor intensity and sensory properties of the NFEs differed greatly depending on the NFE source. Two of the yeast extract-based NFEs elicited higher umami intensity than the other NFEs. Addition of NaCl increased some of the savory-related flavors and the perceived viscosity of the sample. Aroma intensities, in general, were enhanced at the higher temperature, whereas flavor, aftertaste, and mouthfeel attributes were perceived to be stronger at the lower temperature.

• 미생물학회지
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• 제31권3호
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• pp.203-207
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• 1993

Five different secretion vectors were constructed by varying the signal sequences and .alpha.-antitrypsin (.alpha.1-AT) a numan secretory protein, was produced from yeast cells. The signal sequences used are those of acid phosphatase (PH05) and .alpha.-factor (M f.alphal1) of Saccharomyces cerevisiae, glucoamylase (STA1) of Saccharomyces diastaticus, and human .alpha.1-AT. Four vectors directed the efficient secretion of .alpha.1-AT ito the culture media. The secretion vector carrying the glucoamylase signal sequence (pGAT11) showed the highest efficiency of secretion. About 70% of .alpha.1-AT produce dwere secreted into the media. The endo H treatment of partially purified .alpha.1-AT indicates that the secreted .alpha.1-AT appeared to be glycosylated. This glycosylation pattern was altered when amino acid substitution mutations were introduced at the three glycosylation sites of .alpha.-AT.