• Microbiology and Biotechnology Letters
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• v.16 no.3
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• pp.187-192
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• 1988

Production of 4-androstene-3,17-dione(AD) from cholesterol by microbial conversion was investigated. To facilitate the solubilization of cholesterol in the fermentation broth, ethanol was used as an organic solvent. Inhibition on cell growth by ethanol was observed to be negligible upto 2% (V/V) concentration. Microbial conversion was successfully carried out with high yield when the cholesterol was added at early logarithmic growth phase with pH control at 7.0. In order to improve the process productivity, bioconversion was conducted at various mode of cholesterol addition ; 0.1% (V/W) of cholesterol was found to be most appropriate for solubilization in ethanol and was added intermittently. When added three time(total 3 g/$\ell$), overall bioconversion yield reached upto 65% while single addition of same amount of cholesterol (3 g/$\ell$) yielded about 40% conversion.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.341-346
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• 2016

The AMY2B gene, encoding human pancreatic ${\alpha}$-amylase isozyme (HPA II), was expressed in Pichia pastoris, and the effects of chloride ions on HPA II activity toward starch substrates were investigated. As seen with chloride ion-dependent ${\alpha}$-amylases-including HPA I, the isozyme of HPA II-chloride ions increased enzyme activity and shifted the optimal pH to an alkaline pH. The activity enhancement by chloride was more significant at pH 8 than that at pH 6, suggesting that the protonation state of the general acid/base catalyst of HPA II was important for the hydrolysis of starches at an alkaline pH because of the increase in its $pK_a$ by chloride ions. The turnover values for cereal starches as the substrates markedly increased in the presence of chloride by up to 7.2-fold, whereas that for soluble starch increased by only 1.7-fold. Chloride inhibited substrate hydrolysis at high substrate concentrations, with $K_i$ values ranging from 6 to 15 mg/mL.

• Food Engineering Progress
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• v.23 no.3
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• pp.209-216
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• 2019

The effects of fermentation on soy embryo have been investigated using lactic acid bacteria, Lactobacillus acidophilus (LA), Lactobacillus bulgaricus (LB), Streptococcus thermophilussei (ST), and Lactobacillus plantarum (LP). As a result of the fermentation test of the isoflavone conversion by strain type, inoculation content, and fermentation time, the optimum conditions were LP bacterium, an inoculum amount of 5%, and a fermentation time of 24 hours. The composition of the isoflavone glycosides in the control was the highest in the order of glycitin> daidzin> genistin. When fermented with lactic acid bacteria, glycoside content decreased, and aglycone content increased. The order of composition was daidzein>glycitein>genistein. In the fermentation with LP bacterium, soyasaponin Ab content decreased and Ba and Bb content increased. Upon assessing the result of the experiment, it was found that the pH of the fermentation broth had a great influence in the bioconversion of isoflavone and soyasaponin. In the case of fermentation by pH 6 broth, aglycone and Bb content was the highest. The increase of aglycone content by fermentation reaction with the LP bacterium can increase the physiological activity and functionalization of soy embryo, which is a byproduct of processing.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.23-30
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• 1998

The cryIB, truncated cryIB$[cryIB({\alpha})]$, cryIA(b), and cytA genes, encoding 135-, 89-, 131-, and 27-kDa proteins, respectively, from Bacillus thuringiensis were cloned into a shuttle vector pBES and expressed in E. coli and Bacillus species. The morphology and solubility in alkaline buffer of the insecticidal crystal proteins were investigated. Transformation of intact cells of E. coli and Bacillus species was achieved by electroporation. High field strength of 11.0 kV/cm and resistance of 129 ohms were required for efficient transformation of E. coli strains and 4.5 kV/cm and 48 ohms for Bacillus species. Strains of recombinant E. coli and Bacillus species produced the insecticidal crystal proteins and accumulated as the same bipyramidal and irregular structures as those of CryIB and IA(b) and CytA of B. thuringiensls, respectively. The insecticidal crystal proteins accumulated in recombinant E. coli wire smaller in size than those in recombinant Bacillus species. The solubility in alkaline buffer of the insecticidal crystal proteins of recombinant E. coli increased gradually as the pH increased, whereas in the case of Bacillus species the solubility increased gradually as the pH increased up to 9 and then the solubility increased greatly up to two times higher than that of E. coli proteins.

• KSBB Journal
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• v.10 no.3
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• pp.283-291
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• 1995

The characteristics of aminopeptidase M(ApM) immobilized covalently on Cellufine Formyl and the continuous production of authentic human growth hormone(hGH) from methionyl human growth hormono(met-hGH) using the column reactor packed with immobilized ApM were investigated. Immobilized ApM with the proportion of 2.3mg ApM per 1g Cellufine Formyl gel had the highest met-hGH conversion activity. The optimum pH(7.0) and temperature($55^{\circ}C$) showed no appreciable difference between free and immobilized enzymes and the optimum temperature in continuous operation of the column reactor was also found to be $55^{\circ}C$. Under the conditions at which met-hGH was converted completely to hGH, the yield and productivity were about 77% and 0.8mg hGH/ml$.$h, respectively. In two column reactors of different sizes, met-hGH was converted to hGH with the same conversion rates and hGH yields at the same space velocities. The half-life of the reactor systems at $45^{\circ}C$ and $55^{\circ}C$ were projected from the continuous operations for 90 days to be 225 days and 81 days, respectively.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.369-373
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• 1988

The gene for thermostable alpha-amylase from the thermostable bacterium Bacillus licheniformis has been cloned and expressed in Escherichia coli. The Alpha-amylase producing E. coli cells contained a 7.4 kb chimeric plasmid (pTA 322) which was composed of the vector pBR322 and a 3.1 kb EcoRI fragment of B. licheniformis DNA. The alpha-amylase from cloned fragement was shown to be indistlnguishable from that of B. licheniformis in the optimum temperature of 9$0^{\circ}C$, heat stability and the pH stability. The foreign gene was expressed efficiently in E. coli and stably maintained.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.209-215
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• 2005

Lactoferrin is an iron-binding glycoprotein with many biological roles, including the protection against microbial and virus infection, stimulation of the immune system. We developed the transgenic Siberian ginseng (Acanthopanax senticosus) cell cultures producing the human lactoferrin (hLf) protein following Agrobacterium tumefaciens-mediated transformation. A construct containing a targeting signal peptide from tobacco endoplasmic reticulum fused to hLf cDNA under the control of an oxidative stress-inducible SWPA2 promoter was engineered. Transgenic Siberian ginseng cultured cells to produce a recombinant hLf protein were successfully generated and confirmed by PCR and Southern blot analysis. ELISA and western blot analysis showed that full length-hLf protein was synthesized in the transgenic cells. The production of hLf increased proportionally to cell growth and reached a maximal (up to 3% of total soluble proteins) at the stationary phase. These results suggest that the transgenic Siberian ginseng cultured cells in this study will be biotechnologically useful for the commercial production of medicinal plant cell cultures to produce hLf protein.

• The Journal of Natural Sciences
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• v.5 no.1
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• pp.37-45
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• 1992

The gene coding for $\beta$-galactosidase of Neisseria lactamica 2118 was cloned into Escherichia coli MC 1061. The isolated 6.5 Kb EcoR I fragement and 7.2 Kb BamH I fragment of chromosomal DNA in Southern hybridization were ligated to a vector plasmid pBR322 and then transformed into Escherichia coli MC 1061 cells. Finally, I obtained three clones as $\beta$-galactosidase positive clone by colony hybridization and Southern hybridization($\beta$-galactosidase probe: lac Z gene of pMC1871). Three recombinant plasmids(pNL.13. 17 and 24) were found to contain the 7.2Kb BamH I fragment originated from Neisseria lactamica 2118 chromosomal DNA by Southern hybridization and pNL 24 was showed high homology to probe especially and also its physical map was constructed.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.469-474
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• 2010

In this study, we isolated two species of bacteria for the powerful biotrasnformation of ginsenosides from Kimchi and human feces. Using biochemical tests and 16s rRNA sequencing, the selected strains were identified as Latobacillusplantarum (CKDHC0801) and Lactobacillussakei (CKDHC0802). Changes in cell growth and pH were examined in red ginseng. CKDHC 0801 and CKDHC 0802 reached their maximum growth phase after 24 hr and 48 hr, respectively, whereas the combined culture of CKDHC 0801 and CKDHC 0802 showed higher cell growth than bacterial strain alone. During fermentation of CKDHC 0801 and the combined culture, the pH values decreased from 5.2 to 4.2 after 24 hr, but CKDHC 0802 reached pH of 4.2 after 3day. The identities of ginsenosides were biotransferred from high molecular (Rg1 and Rb2) to low molecular (Rg3, Rg5, Rk1, PPD) by fermentation of both bacteria. Therefore, the results of this study demonstrate that CKDHC 0801 and CKDHC 0802 could be used to enhance to effects of red ginseng.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.606-612
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• 2022

The purpose of this study is to convert hydrophobic dyestuff to hydrophilic dyestuff by reacting cationic collector with anionic dyestuff and reaction anionic collector with cationic dyestuff. The removal of colors from aqueous solutions and/or dispersions has been studied by dispersed-air flotation in a batch column. In this studies used generated micro bubble by ceramic gas diffuser having micro pore size for air flotation process. In this study, a ceramic gas diffuser with micro pore size was used to generate micro bubbles for the air flotation process. Two colours were used for the experiments: Basic Yellow 1 (cationic dyestuff) and Direct Orange 10 (anionic dyestuff). All two were effectively removed by flotation within 8 mins. Sodium dodecyl sulfate, sodium oleate (an anionic collector), and amines (a cationic collector) were found to be effective as collectors in the removal of color, which was found to be related to the pH of the solution and the amount of collector added to it, with high collector dosages causing the process to become pH-independent.