• Korean Journal of Microbiology
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• v.28 no.1
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• pp.1-5
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• 1990

The coding sequence of hepatitis B viral core antigen (HBcAg) (subtype adr) contains two in-phase initiation codons, one for precore and the other for core antigen gene. To study the expression of core antigen and the role of precore region, the coding sequence of HBcAg with or without precore (pre-C) region were subcloned into yeast expression vector containing phosphoglycerate kinase (PGK) promoter. To study the role of upstream region in the expression of the core antigen, a series of 5' deletion mutants were also subcloned into the vector. After transformation into various host strains, the expression of HBcAg were analysed by radio-immunoassat. Under optimal condition of core antigen gene expression in yeast, the highest amount of antigen was detected in the cell line SHY4 containing pGKHBc plasmid composed of the yeast PGK gene promoter, terminator and C-gene. Regardless of the presence of precore region, core antigen was not detected in the medium but in cell extract. These results suggest that precore region cannot affect the secretion of core antigen in Saccharomyces cerevisiae.

• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.28-34
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• 1999

Ganoderan (GAN), an immunomodulating ${\beta}$-glucan from mushroom Ganoderma lucidum, was evaluated for its ability to induce formation of nitric oxide (NO), tumor necrosis factor-${\alpha}$(TNF-${\alpha}$) and transforming growth factor (TGF-${\beta}$) from rat Kupffer cell in vitro. Hepatic macrophages activated by GAN significantly elevated concentration of NO and TNF-${\alpha}$ in cultured medium, but not significantly elevated that of TGF-${\beta}$. GAN-activated Kupffer cells secrete 14.9${\mu}$M (p<0.01) of NO and 2619.5${\rho}$g/ml (p<0.01) of TNF-${\alpha}$after 36hr of incubation at 37$^{\circ}C$. The results revealed that GAN enhanced 4-fold production of NO and 19 fold formation of TNF-${\alpha}$ compared to the control. The proliferation of GAN-activated Kupffer cells was inhibited as compared with its negative control. Comparing the activity among glucans derived from microorganisms, highly branched zymosan, glucomannan from Saccharomyces cerevisiae, significantly increased TNF-${\alpha}$ and NO production. These results indicate that the ${\beta}$-glucan from G. lucidum activates rat Kupffer cell and secretes NO and TNF-${\alpha}$. It also suggest that rat Kupffer cell posses certain receptor for ${\beta}$-anomeric glucan.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.767-774
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• 2010

In this study, the problems of high caloric content, increased maturation time, and off-flavors in commercial beer manufacture arising from residual sugar, diacetyl, and acetaldehyde levels were addressed. A recombinant industrial brewing yeast strain (TQ1) was generated from T1 [Lipomyces starkeyi dextranase gene (LSD1) introduced, ${\alpha}$-acetohydroxyacid synthase gene (ILV2) disrupted] by introducing Saccharomyces cerevisiae glucoamylase (SGA1) and a strong promoter (PGK1), while disrupting the gene coding alcohol dehydrogenase (ADH2). The highest glucoamylase activity for TQ1 was 93.26 U/ml compared with host strain T1 (12.36 U/ml) and wild-type industrial yeast strain YSF5 (10.39 U/ml), respectively. European Brewery Convention (EBC) tube fermentation tests comparing the fermentation broths of TQ1 with T1 and YSF5 showed that the real extracts were reduced by 15.79% and 22.47%; the main residual maltotriose concentrations were reduced by 13.75% and 18.82%; the caloric contents were reduced by 27.18 and 35.39 calories per 12 oz. Owing to the disruption of the ADH2 gene in TQ1, the off-flavor acetaldehyde concentrations in the fermentation broth were 9.43% and 13.28%, respectively, lower than that of T1 and YSF5. No heterologous DNA sequences or drug resistance genes were introduced into TQ1. Hence, the gene manipulations in this work properly solved the addressed problems in commercial beer manufacture.

• Korean Journal of Microbiology
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• v.28 no.2
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• pp.128-133
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• 1990

The chromatin of all higher eukaryotic cells contains a group of very basic low-mole-cular weight proteins, the histones. But much less is known about histones in lower eukaryotes. Our purpose was to study the histones of the genus Rhizopus. After isolation and purification of nucleoprotein the basic nucleoproteins were analyzed by gel electrophoresis, in sodium dodecyl sulfate as well as acid/urea gels and compared with calf thymus histones. Their electrophoretic mobility in polyacrylamide gel indicate that they are histone homologous, although not identical, to the H2A, H2B, H3 and H4 histones of mammals with the exception of H1. The result suggests that Rhizopus thus appears to contain histone proteins which are homologous to the histones from in higher eukaryotes. The similarity between the calf thymus histone H1 and the Rhizopus high band group remains to be discussed.

• BMB Reports
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• v.28 no.5
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• pp.437-442
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• 1995

The potency of yeast-derived methionyl-free human growth hormone (rhGH), which was obtained by removal of the N-terminal Met from methionyl-hGH, was estimated by in vitro and in vivo assays. In radio-receptor assay where the binding affinity of growth hormone to the receptor was estimated, the recombinant hGH showed 2.9 international units (IU) per mg of specific activity. In contrast, pitUitary-derived human growth hormone had a slightly lower receptor binding activity (2.5 IU/mg) compared with recombinant growth hormone. For the in vivo assay, efficacy of rhGH was tested by use of hypophysectomized rats, in which pituitary organs were surgically removed, resulting in the termination of growth hormone secretion. The weight-increase in rats by the injection of rhGH was almost identical to the result obtained by the injection of the same amount of pituitary-derived (international standard) hGH. A comparision of the secondary structures of rhGH and rMet-hGH by circular dichroism spectrophotometer demonstrated that the removal of the methionyl residue from rMet-hGH did not exert any effect on the structure of the growth hormone. In conclusion, methionyl-free human growth hormone produced from yeast was highly potent in biological activity and maintained a legitimate three dimensional structure.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1791-1799
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• 2018

Weaning stress can affect the growth performance and intestinal health of piglets. Dietary alternatives to antibiotics, such as dietary probiotics, especially those containing multiple microbial species, are a preventive strategy for effectively controlling post-weaning diarrhea. In this study, we investigated forty-eight crossbred piglets in three treatment groups for 21 days: the control and experimental groups were supplemented with Enterococcus faecium DSM 7134, Bacillus subtilis AS1.836 plus Saccharomyces cerevisiae ATCC 28338 (EBS) or Lactobacillus paracasei L9 CGMCC No. 9800 (EBL). On day 21, weaned piglets supplemented with two kinds of probiotic complexes showed increased growth performance and significantly reduced post-weaning diarrhea (p < 0.05). The EBS treatment increased acetic acid and propionic acid in the feces (p < 0.05), and the EBL treatment increased fecal acetic acid, propionic acid, butyrate and valerate (p < 0.05). Moreover, the fecal microbiota of the piglets changed markedly in EBL treatment. The addition of EBS and EBL may have similar effects on the prevention of diarrhea by improving the intestinal morphology and regulating the microbiota during the weaning period.

• KSBB Journal
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• v.31 no.2
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• pp.134-143
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• 2016

Lycii fructus has been traditionally used as a preventive and therapeutic medicine to treat enervation and diverse chronic diseases. In this study, we investigated whether fermentation of Lycii fructus extract (LE) increases the enzymatic activity of the alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). The fermentation of LE by Bacillus subtilis subsp. subtilis and Saccharomyces cerevisiae IFO 2376 was shown to increase the enzymatic activity of ADH and ALDH. TLC analysis of LE and fermented LE (FLE) showed that ADH and ALDH activities increased in different spots. Fraction No. 66 of LE and fraction No. 68 of FLE by Silica gel chromatography showed increased ADH activity of 129.1% and 148.9%, respectively. Fractions No. 128 of LE and FLE by Silica gel chromatography showed increased ALDH activity of 134.1% and 148.1%, respectively. The fraction No. 68 of FLE obtained by HPLC showed new peaks at $R_t$ 11.938min, $R_t$ 22.072min and $R_t$ 28.842min, indicating that ADH activity was increased. The LE and FLE fractions with the greatest increases in ADH activity peaked at the same time ($R_t$ 13min),whereas the LE and FLE fractions with the greatest increases in ALDH activity peaked at different times ($R_t$ 16.307min and $R_t$ 36.640min, respectively).

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.73-77
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• 2002

The Sec61 trimeric complex ($\alpha$,$\beta$, and ${\gamma}$ subunits) is one of the Sec-complex responsible for post-translational protein translocation across the endoplasmic reticulum membrane in diverse organisms. In this study, a cDNA encoding the Sec61p ${\gamma}$ subunit homologue was isolated from the cDNA library of the mole cricket, Gryllotalpa orientalis. Sequence analysis of a 442-bp cDNA clone showed it to contain an open reading frame of 68 amino acid residues consisted of 204-bp. The homologues of the gene were found in the GenBank database in a diverse organism including insect, mammals, fungi, and plants. The deduced amino acid sequence of Sec61p ${\gamma}$ subunit homologue of the mole cricket showed the highest homology to the gene of the singly known insect, Drosophila melanogester (93% identity), and the least homology to that of the baker's yeast, Saccharomyces cerevisiae (37.2%). Phylogenetic analysis also confirmed a close relationship between the insect Sec61p ${\gamma}$ subunit homologues of G. orientalis and D. melanogester. Hydropathy analysis of the cricket mole and published other data suggested that the hydrophobic segment close to C-terminus is predicted to be the putative membrane anchor, Multiple alignment of the Sec61p ${\gamma}$ subunit homologue among several organisms showed the presence of several conserved domains including the conserved proline at position 28.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.94-102
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• 2020

Brown rice Makgeolli was brewed by using the Saccharomyces cerevisiae strain SRCM102596 under different fermentation conditions: temperatures at 20 and 25℃ and Nuruk ratios of 5, 10, and 15%. There were no significant differences in the pH and total acidity between samples. The alcohol content at the different nuruk ratios varied significantly by the days in the fermentation process. The major free sugars were maltose, glucose, and fructose, and they gradually reduced with fermentation. The major organic acids in the brown rice Makgeolli were oxalic acid, citric acid, malic acid, succinic acid, and acetic acid. The lactic acid content increased with the number of days in the fermentation process. Among the 24 different free amino acid contents identified, the total free amino acid content of, especially, threonine, serine, and alanine were high in the brown rice Makgeolli, at 20℃ and nuruk ratio of 10%.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1776-1783
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• 2006

Despite being a rich source of protein (28-34%), karanj (Pongamia glabra) cake is found to be bitter in taste and toxic in nature owing to the presence of flavonoid (karanjin), tannin and trypsin inhibitor, thereby restricting its safe inclusion in poultry rations. Feeding of karanj cake at higher levels (>10%) adversely affected the growth performance of poultry due to the presence of these toxic factors. Therefore, efforts were made to detoxify karanj cake by various physico-chemical methods such as dry heat, water washing, pressure cooking, alkali and acid treatments and microbiological treatment with Sacchraromyces cerevisiae (strain S-49). The level of residual karanjin in raw and variously processed cake was quantified by high performance liquid chromatography and tannin and trypsin inhibitor was quantified by titrametric and colorimetric methods, respectively. The karanjin, tannin and trypsin inhibitor levels in such solvent and expeller pressed karanj cake were 0.132, 3.766 and 6.550 and 0.324, 3.172 and 8.513%, respectively. Pressure-cooking of solvent extracted karanj cake (SKC) substantially reduced the karanjin content at a cake:water ratio of 1:0.5 with 30-minute cooking. Among chemical methods, 1.5% (w/w) NaOH was very effective in reducing the karanjin content. $Ca(OH)_2$ treatment was also equally effective in karanjin reduction, but at a higher concentration of 3.0% (w/w). A similar trend was noticed with respect to treatment of expeller pressed karanj cake (EKC). Pressure cooking of EKC was effective in reducing the karanjin level of the cake. Among chemical methods alkali treatment [2% (w/w) NaOH] substantially reduced the karanjin levels of the cake. Other methods such as water washing, dry heat, HCl, glacial acetic acid, urea-ammoniation, combined acid and alkali, and microbiological treatments marginally reduced the karanjin concentration of SKC and EKC. Treatment of both SKC and EKC with 1.5% and 2.0% NaOH (w/w) was the most effective method in reducing the tannin content. Among the various methods of detoxification, dry heat, pressure cooking and microbiological treatment with Saccharomyces cerevisiae were substantially effective in reducing the trypsin inhibitor activity in both SKC and EKC. Based on reduction in karanjin, in addition to tannin and trypsin inhibitor activity, detoxification of SKC with either 1.5% NaOH or 3% $Ca(OH)_2$, w/w) and with 2% NaOH were more effective. Despite the effectiveness of pressure cooking in reducing the karanjin content, it could not be recommended for detoxification because of the practical difficulties in adopting the technology as well as for economic considerations.