• Animal Bioscience
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• v.37 no.2
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• pp.228-239
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• 2024

Objective: The objective of the experiment was to study yeast supplementation (yeast, Y) and dried kratom leaves (DKTL) on the digestibility, ruminal fermentation, blood metabolites and nitrogen balance in goats. Methods: Four of 7 to 8 months old male crossbred (50% Thai Native-Anglo Nubian) goats with average liveweight 20±0.13 kg were randomly assigned according to a 2×2 factorial arrangement in a 4×4 Latin square design to receive four diets ad libitum basis. The study investigated the effects of two levels of yeast (Y) supplementation (Y, 0 and 0.5g/kg dry matter [DM]) along with two levels of DKTL supplementation (DKTL, 0 and 4.44g/kg DM). The experimental groups were as follows: T1 = control group with 0Y+0DKTL, T2 = 0Y+4.44 DKTL, T3 = 0.5Y+0DKTL, and T4 = 0.5Y+4.44 DKTL. Results: The results showed that there were no interactions between Y levels and DKTL levels with respect to total DM intake, but there were significant effects (p<0.05) by levels of Y; goats receiving 0.05 g/kg DM Y had higher than goats fed 0.0 g/kg DM on average (kg/d). A percentage of body weight (% BW) and grams per kilogram of metallic weight (g/kg w^0.75) had no influence on yeast levels and DKTL, but there was a difference (p<0.05) by yeast level Y at 0.5 g/kg DM, being higher compared to the non-supplemented group. Apparent digestibility coefficient of nutrition in the form of (DM, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber) was an increased trend in the Y-level complementary group at 0.5 g/kg DM and DKTL at 4.44 g/kg DM, respectively. Protozoa populations decreased in the group receiving Y levels at 0.5 g/kg DM and DKTL levels at 4.44 g/kg DM when compared to group T1. The acetic acid concentration and methane gas generation decreased (p<0.05) in the group receiving Y levels of 0.5 g/kg DM and DKTL levels of 4.44 g/kg DM, while the amount of propionic acid increased (p<0.05). Conclusion: Effects of feeding combinations of Y and DKTL supplementation on feed showed no interaction effect (Y×DKTL) on feed intake, rumen fermentation, bacterial and fungi population. The effect on protozoal populations was lower in the group that was supplemented with DKTL at 4.44 g/kg DM related to synthetic CH₄ was reduced.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.576-581
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• 2005

Phytase improves the bioavailability of phytate phosphorus in plant foods to humans and animals, and reduces the phosphorus pollution of animal waste. We have engineered the cell surface of the yeast. Saccharomyces cerevisiae, by anchoring active fungal phytase on its cell wall, in order to apply it as a dietary supplement containing bioconversional functions in animal foods and a whole cell bio-catalyst for the treatment of waste. The phytase gene (phyA) of Aspergillus niger with a signal peptide of rice amylase 1A (Ramy1A) was fused with the gene encoding the C-terminal half (320 amino acid residues from the C-terminus) of yeast ${\alpha}-agglutinin$, a protein which is involved in mating and is covalently anchored to the cell wall. The resulting fusion construct was introduced into S. cerevisiae and expressed under the control of the constitutive glyceraldehydes-3-phosphate dehydrogenase (GPD) promoter. Phytase plate assay revealed that the surface-engineered cell exhibited a catalytically active opaque zone which was restricted to the margin of the colony. Additionally, the phytase activity was detected in the cell fraction, but was not detected in the culture medium when it was grown in liquid. These results indicate that the phytase was successfully anchored to the cell surface of yeast and was displayed as its active form. The amount of recombinant phytase on the surface of yeast cells was estimated to be 16,000 molecules per cell.

• Journal of Life Science
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• v.23 no.7
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• pp.886-892
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• 2013

We investigated ethanol production from glycerol after screening of the yeast Pachysolen tannophilus ATCC 32691. For yeast to produce ethanol form glycerol, it is important that aeration is finely controlled. Therefore, we attempted to produce ethanol using a surface-aerated fermentor. When 880 ml of YPG medium (1% yeast extract, 2% peptone, 2% glycerol) was used to produce ethanol, the optimal aeration conditions for ethanol production were a surface aeration rate and agitation speed of 500 ml/min and 300 rpm, respectively. In a fed-batch culture, the maximum ethanol production and the maximum ethanol yield from glycerol (Ye/g) was 5.74 g/l and 0.166, respectively, after 90 hr using the surface-aerated fermentor.

• The Korean Journal of Mycology
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• v.45 no.1
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• pp.23-30
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• 2017

Twenty-two yeast strains of 15 species were isolated from the leaves of 20 trees on Oknyeobong Peak, and 24 yeast strains of 12 species were isolated from the leaves of 20 trees on Yeonjasan Mountain in Daejeon city, Korea. Cryptococcus bestiolae (5 strains) and Aureobasidium pullulans (8 strains) were the predominant isolates from Oknyeobong Peak and Yeonjasan Mountain, respectively. Of a total of 46 yeast strains, Cryptococcus kuetzingii JSL508, Cryptococcus vishniacii JSL509, and Dioszegia takashimae JSL510 from Okyeobong Peak, and Plowrightia periclymeni JSL514, Erythrobasidium hasegawanium JSL0193, and Rhodotorula nothofagi JSL0196 from Yeonjasan Mountain were determined to be yeast strains that were yet unrecorded in Korea. Morphological and cultural characteristics of these unrecorded yeasts were investigated. Erythrobasidium hasegawanium JSL0193 and Rhodotorula nothofagi JSL0196 did not form ascospores and pseudomycelia. All the strains, except Dioszegia takashimae JSL510, were halotolerant or halophilic, and Cryptococcus kuetzingii JSL508 and Dioszegia takashimae JSL510 were thermophilic, growing at $37^{\circ}C$.

• IMMUNE NETWORK
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• v.2 no.3
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• pp.137-141
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• 2002

Among the members of the inhibitor of apoptosis (IAP) protein family, only Livin and survivin have been reported to have variant forms. We have found a variant form of c-IAP2 through the interaction with the X protein of HBV using the yeast two-hybrid system. In contrast to the wild-type c-IAP2, the variant form has two stretches of sequence in the RING domain that are repeated in the C-terminus that would disrupt the RING domain. We demonstrate that the variant form has an inhibitory effect on TNF-mediated $NF-{\kappa}B$ activation unlike the wild-type c-IAP2, which increases TNFmediated $NF-{\kappa}B$ activation. These results suggest that this variant form has different activities from the wild-type and the RING domain may be involved in the regulation of TNF-induced $NF-{\kappa}B$ activation.

• Animal cells and systems
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• v.4 no.2
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• pp.157-163
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• 2000

Yeast pheromone a-factor is a 13-amino acid peptide hormone that is synthesized as a part of a larger precursor, prepro-$\alpha$-factor, consisting of a signal peptide and a proregion of 64 amino acids. The carboxy-terminal half of the precursor contains four tandem copies of mature $\alpha$-factor. To investigate the molecular basis of intracellular sorting, proteolytic processing, and storage of the peptide hormone, yeast prepro-$\alpha$-factor precursors were heterologously expressed in rat pituitary $GH_3 cells. When cells harboring the precursor were metabolically labeled, a species of approximately 27 kD appeared inside the cells. Digestion with peptide: N-glycosidase F (PNG-F) shifted the molecular mass to a 19 kD, suggesting that the 27 kD protein was the glycosylated form as in yeast cells. The nascent polypeptide is efficiently targeted to the ER in the $GH_3 cells, where it undergoes cleavage of its signal peptide and core glycosylation to generate glycosylated pro-a-factor. To look at the post ER intracellular processing, the pulse-labelled cells were chased up to 2 hrs. The nascent propeptides disappeared from the cells at a half life of 30 min and only 10-25% of the newly synthesized, unprocessed precursors were stored intracellularly after the 2 h chase. However, about 20% of the pulse-labeled pro-$\alpha$-factor precursors were secreted into the medium in the pro-hormone form. With increasing chase time, the intracellular level of propeptide decreased, but the amount of secreted propeptide could not account for the disappearance of intracellular propeptide completely. This disappearance was insensitive to lysosomotropic agents, but was inhibited at $16^{circ}C or 20^{\circ}C$, suggesting that the turnover of the precursors was not occurring in the secretory pathway to trans Golgi network (TGN) or dependent on acidic compartments. From these results, it is concluded that a pan of these heterologous precursors may be processed at its paired dibasic sites by prohormone processing enzymes located in TGN/secretpry vesicles producing small peptides, and that the residual unprocessed precursors may be secreted into the medium rather than degraded intracellularly.

• The Korean Journal of Mycology
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• v.50 no.1
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• pp.65-73
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• 2022

This study aimed to isolate wild yeasts from seawaters and soils samples of the Haeundae and Mongdol beaches on the southern coast of Korea, and to characterize these unrecorded wild yeast strains. In total, 41 strains, representing 37 different species of wild yeast were isolated from 70 samples collected from the beaches. Among these, 14 strains were isolated from the alkalophilic medium of yeast extract-peptone-dextrose (YPD) medium (pH 9.0), and 27 strains were isolated concurrently on general YPD medium (pH 6.5). Among the 41 isolated wild yeast strains, Candida insectorum HUD 16-3(JSL-KSS-002) and Metschnikowia citriensis HUD 12-5(JSL-KSS-001) had not previously been recorded. We investigated the microbiological characteristics of these two unrecorded yeast strains and three other strains-, Cystobasidium lysinophilum JSC 52-2(JSL-GGU-019), Candida takata NMD 11-1(JSL-GGU-017) and Candida panamensis ASG 58M-2(JSL-GGU-018) from Jangseoncheon in Jellabuk-do and Jangtaesan in Deajeon city. All five previously unrecorded yeasts were oval and did not form spores. All strains grew well in YPD and yeast extract-malt extract media in a vitamin-free medium. Two strains, including C. insectorum HUD 16-3(JSL-KSS-002) grew well in a 15% NaCl-containing YPD medium. Three strains, including Cys. lysinophilum JSC52-2(JSL-GGU-019) assimilated lactose, and all strains assimilated starch.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.1
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• pp.35-39
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• 1997

Studies on the glucose isomerase produced by alkalophilic Streptomyces sp. B-2. Glucose Isomerase (E. C. 5.3.1.5) which reversibly catalyzes reaction between D-glucose and D-fructose was demonstrated in cell free extracts of alkalophilic Streptomyces sp. B-2 isolated form soil. The maximum enzyme activity was found at glucose concentration 4(g/$\ell$) , xylose concentration 6(g/$\ell$), magnesium ion 1.0(g/$\ell$), yeast extract concentration 2.0(g/$\ell$), peptone concentration 3(g/$\ell$).

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.153-156
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• 2000

Xylan, the major hemicellulose component of many plants, occurs naturally in a partially acetylated form and lignin, the most resistant component in plant cell wall degradation, is also attached to ${\beta}-1,4-linked-D-xylose$ backbone through the ester linkage. Esterases are required to release the esterified substituent and acetyl esterases are important in the complete degradation of acetylated polysaccharides, like pectins and xylans. The gene(Axe) encoding acetyl xylan estarase(AXE) was isolated from genomic ${\lambda}$ library from Aspergillus ficuum. Nucleotide sequencing of the Axe gene indicated that the gene was separated with two intervening sequences and the amino acid sequence comparison revealed that it was closely related to that from A. awamori with the 92 % indentity. Heterologous expression of AXE was conducted by using YEp352 and Saccharomyces cerevisae 2805 as a vector and host expression system, respectively. The Axe gene was placed between GAL1 promoter and GAL7 terminator and then this recombinant vector was used to transform S. cerevisiae 2805 strain. Culture filtrate of the transformed yeast was assayed for the presence of AXE activity by spectrophotometry and, comparing with the host strain, four to five times of enzyme activity was detected in culture filtrate of transformed yeast.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.160-166
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• 2004

The optimal conditions for production of Monascus sp. KM100l cell mass on submerged culture and production of monacolin K on rice solid culture were investigated. An overproducing mutant of Monascus pigments, KM 1001 mutant, from Monascus purpureus KCCM60016 was selected by NTG treatment. The optimal medium for the production of KM100l mutant cell mass is instructed to be composed of 3% glucose, 2% yeast extract, 0.1 % KH$_2$PO$_4$, 0.05% The optimal conditions for production of Monascus sp. KM100l cell mass on submerged culture and production of monacolin K on rice solid culture were investigated. An overproducing mutant of Monascus pigments, KM 1001 mutant, from Monascus purpureus KCCM60016 was selected by NTG treatment. The optimal medium for the production of KM100l mutant cell mass is instructed to be composed of 3% glucose, 2% yeast extract, 0.1 % KH$_2$The optimal conditions for production of Monascus sp. KM100l cell mass on submerged culture and production of monacolin K on rice solid culture were investigated. An overproducing mutant of Monascus pigments, KM 1001 mutant, from Monascus purpureus KCCM60016 was selected by NTG treatment. The optimal medium for the production of KM100l mutant cell mass is instructed to be composed of 3% glucose, 2% yeast extract, 0.1 % $(KH_2PO_4$, 0.05% $MgSO_4{\cdot}7H_2O$, 0.2% L-asparagine, pH 4.5, and the optimal inoculum size and shaking speed were $1.5{\times}10^6$ spores/50 m1 medium and 150 rpm, respectively. On optimal conditions, 4.1 g/l of the cell mass was obtained at 28$^{\circ}C$ for 3 days. The mycelium were inoculated on 500 g of steamed rice using vinyl bag ($30.6{\times}44$ cm) and incubated at $30^{\circ}C$, 85% humidity for 21 days. Lactone form monacolin K was rapidly increased for 2 days and reached highest concentration of monacolin K (2,930 mg/kg) for 15 days, and monacolin K was decreased after 15 days.