• Microbiology and Biotechnology Letters
• /
• v.23 no.5
• /
• pp.588-592
• /
• 1995

Fed-batch fermentation was used to produce the high concentrations of poly-$\beta $-hydroxybutyrate (PHB) and poly-$\beta $-(hydroxybutyrate-co-hydroxyvalerate) (PHB/V). Specific growth rate ($\mu $), yield of cell from glucose (Y$_{x/s}$) were calculated from the two samples in 3 to 5 hours of interval and they were reflected on the determination of glucose feeding rate to maintain the glucose concentration at around 10 g/l in the culture broth. PHB was accumulated after the nitrogen became limited at 60 g/l of dry cell weight by changing ammonia water to 4N-NaOH solution. As results, the final dry cell weight (DCW) of 170 g/l, PHB of 115 g/l were obtained in 50 hours and the overall productivity was 2.4 g/l$\cdot $h. After PHB accumulation, cosubstrate of glucose and propionic acid (PA) was fed to accumulate PHB/V. But, PA feeding rate was decreased from 3 g/l$\cdot $h to 1 g/l$\cdot $h to prevent PA from accumulating to high level in the broth, which is very inhibitory to the cells. As results, DCW, PHB and PHV were 147.5 g/l, 90 g/l and 8 mole % of hydroxyvalerate, respectively.

• BMB Reports
• /
• v.31 no.2
• /
• pp.123-129
• /
• 1998

Foreign proteins, $endo-{\beta}-1,4-glucanase$ of Bacillus subtilis, preS1+S2 region of hepatitis B virus large surface antigen, human ${\beta}_2-adrenergic$ receptor ($h{\beta}_{2}AR$), and bovine growth hormone (bGH) were expressed in Saccharomyces cerevisiae and secreted into the medium. These proteins were expressed using the alcohol dehydrogenase I (ADH1) promoter of Saccharomyces cerevisiae and secreted by signal sequence of the 97 K killer toxin gene of doublestranded linear DNA plasmid (pGKL1) of S. cerevisiae. All these proteins underwent severe modifications; in particular, N-glycosylation in the case of $endo-{\beta}-1,4-glucanase$, $h{\beta}_2AR$, and preS1+S2. Seventy four percent of the expressed $endo-{\beta}-1,4-glucanase$ was secreted into the culture medium. Highly modified proteins were detected in the culture medium and in the cell. Expressed $h{\beta}_2AR$, which has seven transmembrane domains, remained in the cell. The degrees of secretion and modification and the states of proteins in the culture medium and in the cell were quite different. These results indicated that the nature of the protein has a critical role in its secretion and modifications.

• The Journal of Korean Medicine
• /
• v.21 no.1
• /
• pp.53-61
• /
• 2000

Objectives: This study was camed out to examine the effect of five fractions of aqueous extract from Artemisia capillaris THUNB(ACT), on TGF, 1-induced apoptosis, cell viability, cell cycle progression and mRNA expression of apoptosis-related genes in human hepatocyte cell line HepG2. Methods: This study employed Tryphan blue exclusion assay, DNA fragmentation assay, Cpp32 protease activity assay and Quantitative RT-PCR analysis. Results: In the Tryphan blue exclusion assay, the butanol fraction of ACT with $TGF{\beta}$, l showed magnificent (Nice word, ut is it appropriate in a medical abstract\ulcorner) viability and the H2O fraction of ACT with $TGF{\beta}$, l also showed higher viability than only $TGF{\beta}$, l-treated group. DNA fragmentation assay showed that the butanol fraction and the H2O fraction carried inhibitory effects on apoptosis induction, with the butanol fraction displaying greater effects. The Cpp32 protease activity assay showed that the butanol fraction decreased Cpp32 protease activity. The H2O fraction of ACT had no significant effect on the Cpp32 protease activity. Quantitative RT-PCR showed that the butanol fraction suppressed Bax, p 15/INK4B, p21/Waf1, PAI-1 and increased Bcl-2 gene. Conclusions: The data shows that butanol fraction of ACT increases the hepatocyte viability and has the hepatocellular protective effect by the suppression of $TGF{\beta}$, l induced-apoptosis through gene regulation.

• Journal of the Korean Ceramic Society
• /
• v.41 no.12 s.271
• /
• pp.921-928
• /
• 2004

Calcium phosphate powders have been prepared by using $Ca(OH)_2\;and\;H_{3}PO_4$ solution under various conditions such as pH, calcination temperature, and reaction time. ${\beta}-TCP({\beta}-tricalcium phosphate)$and HAp(hydroxyapatite) were synthesized at pH=5.21 and pH > 7.62, respectively. From XRD results, $Ca(OH)_2\;and\;H_{3}PO_4$ solution reacted quickly to form HAp, which was structurally stable up to 16h. Calcination temperature having good crystallinity is revealed to be at $1200^{\circ}C$. SEM analysis showed that ${\beta}-TCP$ and HAp with needle type were synthesized at pH 5.21 and pH 7.62, respectively. However, at pH 9.16, tiny and homogeneous HAp having sphere was prepared and rearranged to show needle morphology. HAp synthesized at pH 9.16 was utilized as bonechina body and calcined. The sample was analyzed its crystallinity, water absorbtion, color, and shape to check physical properties.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.8
• /
• pp.451-459
• /
• 2020

This study aims to examine the relationship of the four factors that increase the protection of minority shareholder investment. The factors are non-controlling shareholders, corporate governance, free cash flow, and shareholder wealth. The data for this study is obtained from the 2017 annual reports of 136 Thai public companies listed in the Market of Alternative Investment of Thailand (MAI). The analysis uses a multiple regression model to determine which factors encourage and which inhibit the protection of minority shareholder investment. The study tests four hypotheses. The results rejected H1 because non-controlling shareholders have negatively correlated with minority shareholder investment protection (beta -0.155 and p-value 0.050). The results accepted H2, H3 and H4 as follows. H2: corporate governance has positively correlated with minority shareholder investment protection (beta 0.17 and p-value 0.031). H3: free cash flow has positively correlated with minority shareholder investment protection (beta 0.214 and p-value 0.007). H4: shareholder wealth has positively correlated with minority shareholder investment protection (beta 0.318 and p-value 0.000). The major findings suggest strong minority shareholder investment protection was enhanced by increasing corporate governance, free cash flow and shareholder wealth. The protection of minority shareholder investment needs to reduce non-controlling shareholding pattern.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.4
• /
• pp.579-587
• /
• 2018

For biotechnological production of high-valued ${\beta}-{\text\tiny{D}}$-hexyl glucoside, the catalytic properties of Hanseniaspora thailandica BC9 ${\beta}$-glucosidase purified from the periplasmic fraction were studied, and the transglycosylation activity for the production of ${\beta}-{\text\tiny{D}}$-hexyl glucoside was optimized. The constitutive BC9 ${\beta}$-glucosidase exhibited maximum specific activity at pH 6.0 and $40^{\circ}C$, and the activity of BC9 ${\beta}$-glucosidase was not significantly inhibited by various metal ions. BC9 ${\beta}$-glucosidase did not show a significant activity of cellobiose hydrolysis, but the activity was rather enhanced in the presence of sucrose and medium-chain alcohols. BC9 ${\beta}$-glucosidase exhibited enhanced production of ${\beta}-{\text\tiny{D}}$-hexyl glucoside in the presence of DMSO, and 62% of ${\beta}-{\text\tiny{D}}$-hexyl glucoside conversion was recorded in 4 h in the presence of 5% 1-hexanol and 15% DMSO.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.19 no.6
• /
• pp.605-611
• /
• 1990

$\beta$-Galactosidase activity was not detected at green mature stage but were 21.79 and 380.23 units/100g-fr. wt. in mature and soft persimmon, respectively. The molecular weight of $\beta$-galactosidase was estimated to be 115, 000 daltons by the method of gel filtration. Vmax and Km value were 0.095m mo1e p-nitrophenyl-galactoside and 1.8$\times$10$^{-2}$ mM, respectively. The optimum temperature and pH of $\beta$-galactosidase were 45$^{\circ}C$ and 4.2, respectively. $\beta$-Galactosidase was inhibited by SDS.

• Korean Journal of Microbiology
• /
• v.27 no.4
• /
• pp.366-372
• /
• 1989

Twenty-one strains were tested for 11$\beta$-hydroxylation of Reichstein's substance S. Four fungi exhibited ability for the reaction, among which Pellicularia fillamentosa showed the highest activity. The 11$\beta$-hydroxylase of this fungus was proved to be induced by the substrate, cycloheximide reducing significantly the activity of the enzyme. Range of optimum pH for the 11$\beta$-hydroxylation was broad and found to be 2.0-8.0. Test of the enzyme activity at different growing stages, from spore to mycelia, showed that the branching stage of hyphae and the mature mycelial stage were the most effective for the Reichstein's substance S transformation. However, 11$\beta$-hydroxylase in the intact spore was turned out to be uninducible with the substrate.

• 한국전자현미경학회:학술대회논문집
• /
• 2001.11a
• /
• pp.84-86
• /
• 2001

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.5
• /
• pp.618-625
• /
• 2009

The objective of this work was to study the direct effects of daidzein on steroidogenesis in cultured mouse Leydig cells. Adult mouse Leydig cells were purified by Percoll gradient centrifugation, and the cell purity was determined using a $3{\beta}$-hydroxysteroid dehydrogenase ($3{\beta}$-HSD) staining method. The purified Leydig cells were exposed to different concentrations ($10^{-7}$ M to $10^{-4}$ M) of daidzein for 24 h under basal and human chorionic gonadotropin (hCG)-stimulated conditions. The cell viability and testosterone production were determined, and the related mechanisms of daidzein action were also evaluated using the estrogen receptor antagonist ICI 182,780 and measuring the mRNA levels of steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450scc), and $3{\beta}$-HSD-1 involved in testosterone biosynthesis. The results revealed that daidzein did not influence cell viability. Daidzein increased both basal and hCG-stimulated testosterone production in a dose-dependent manner, and this effect was statistically significant at concentrations of $10^{-5}$ M and $10^{-4}$ M daidzein (p<0.05). ICI 182,780 had no influence on daidzein action. RTPCR results revealed that $10^{-5}$ M and $10^{-4}$ M daidzein did not exert any obvious influence on the mRNA level of P450scc in Leydig cells. However, in the presence of hCG, these concentrations of daidzein significantly increased the StAR and $3{\beta}$-HSD-1 mRNA levels (p<0.05), but in the absence of hCG, only $10^{-5}$ M and $10^{-4}$ M daidzein up-regulated the StAR and $3{\beta}$-HSD-1 mRNA expression (p<0.05), respectively. These results suggest that daidzein has direct effect on Leydig cells. Daidzein-induced increase of testosterone production is probably not mediated by the estrogen receptor but correlates with the increased mRNA levels of StAR and $3{\beta}$-HSD-1.