• KSBB Journal
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• v.17 no.6
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• pp.586-589
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• 2002

Lipomyces starkeyi KSM 22 produces dextranase and amylase (DXAMase). The addition of 0.02％ (w/v) 2-deoxy-D-glucose or 0.5% (w/v) glycerol into a 1% (w/v) starch medium increased the final activity of DXAMase produced 2.5 fold or 2.4 fold, respectively, compared to that of a 1% (w/v) starch medium. This activity was similar to that produced with 1% (w/v) dextran. The stability of purified OXAMase at 40$\^{C}$ for 3 weeks was tested using the various enzyme stabilizers. With the addition of 25% (v/v) glycerol, 90.9% of initial activity was left after 3 weeks. For practical use, the addition of 1% (v/v) glycerol with 50 mM of CaCl$_2$ or KH$_2$PO$_4$was adequate and maintained 73.4% of the initial activity under the test conditions used.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.383-388
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• 2003

A bacterium producing the extracellular xylanase and CMCase was isolated from soil and has been identified as Bacillus sp. The isolate, named Bacillus sp. A-7, was shown to be very similar to Bacillus licheniformis on the basis of its biochemical and physiological properties. The maximum xylanase and CMCase production were obtained when 2.0% (w/v) glucose and 0.3% (w/v) yeast extract were used as carbon source and nitrogen source, respectively. The best mineral conditions for xylanase and CMCase production were 0.1%(w/v) $CaC1_2$. Among the various feedstuffs, 1.0%(w/v) soybean meal was selected for the best xylanase and CMCase production.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.376-382
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• 1990

An extracellular cellulase producing bacterium YE-5 was isolated from soil, and identified as a Cellulomonas sp. by its taxonomical characteristics. The maximal activities of avicelase (0.35 units/ml), CMCase (3.18 units/ml), FPase (0.315 units/ml) and $\beta$-glucosidase (0.882 units/ml) were obtained when this strain was cultured for 48 hrs at $30^{\circ}C$ in a medium containing 0.8% (w/v) Solka floc, 0.06010 (wlv) urea, 0.1% (w/v) $K_2HP0_4$, 0.1% (w/v) $MgS0_4.7H2_0$, 0.2% (w/v) bacto peptone, 0.2% (w/v) yeast extract and pH 6.5. The cellulase was purified by ammonium sulfate fractionation, DEAE-Sepharose column chromatography and Sephadex 6-100 column chromatography from culture filtrate of Cellulomonus sp. YE-5. The molecular weights of purified avieelase, CMCase I, and CMCase II were estimated to be about 95,000 ~ 105,000, 46,000 ~ 47,000 and 120,000 ~ 125,000, respectively.

• Food Science and Preservation
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• v.11 no.4
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• pp.472-477
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• 2004

This study was carried out to investigate the effect of liquid calcium(LC) on the quality of kimchi during fermentation. LC retarded the decreasing rate of pH and the increasing rate of titratable acidity during fermentation at $10^{\circ}C$, and the effect was more conspicuous at $7.0\%(v/w)$ than at $3.5\%(v/w)$ in each LC type. Microbial counts of total and lactic acid bacteria were lower in LC added kimchi than control before 8 days but higher in LC added kimhi after 8 days. Changes in color of a value were gradually increased, but L and b value were decreased. Calcium content of added LC on kimchi; A concentration $3.5\%(v/w),\;7.0\%(v/w)$ were $103{\sim}110\;mg\%,\;145{\sim}163\;mg\%$ and B concentration $3.5\%,\;7.0\%$ were $140{\sim}151\;mg\%,\;210{\sim}220\;mg\%$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.593-597
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• 2004

This study was conducted to investigate the quality characteristics of liquid calcium acetate (LCAs) and solid calcium acetate (SCAs), Br-LCA, Pe-LCA and Ap-LCA as liquid form, Br-SCA, Pe-SCA and Ap-SCA as solid form. Calcium acetate was prepared by reacting of vinegars [brown rice (Br), persimmons (Pe) and apple (Ap)] and ash of black snail in order to obtain natural water soluble calcium resources. The pHs of the vinegars for preparing calcium acetate (CA) were the range of 2.34 ∼ 3.06, and the contents of the ash of black snail which reacted to 100 mL of the vinegars were 20.43∼23.50 g. The yields of solid CAs from 100 mL of the vinegars were 11.02∼13.01 g. The colors of liquid and solid CAs were light yellow in Ap-LCA and Ap-SCA, brown in Br-LCA and Br-SCA, dark brown in Pe-LCA and Pe-SCA. Calcium contents of Br-LCA, Pe-LCA and Ap-LCA were 3.02, 2.06 and 2.30% (w/v), and those of Br-SCA, Pe-SCA and Ap-SCA were 27.15, 16.31 and 19.48% (w/w), respectively. The solubilities of the solid CAs were 36.82 ∼ 39.92% (w/v) in distilled water, 32.05 ∼ 39.04% (w/v) in Soju, 13.12 ∼ 18.65% (w/v) in thick soysauce, 38.35 ∼ 38.90% (w/v) in ionic beverage, 33.47 ∼ 35.58% (w/v) in yoghurt, while the solid CAs formed the curds in soymilk and milk. The sour and bitter taste of the CAs were lower, while the astringent taste, fishy flavor and savory taste were higher than those of standard CA.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.333-340
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• 2016

An alkaline protease was purified and characterized from an alkalophilic microorganism, Bacillus sp. DK1122, isolated from soil in central Korea. The optimum temperature and pH for the growth of the producer strain were 40℃ and pH 9.0, respectively. The protease was produced aerobically at 40℃ after 24 h incubation in modified Horikoshi I medium (pH 9.0) containing 0.5% (w/v) glucose, 0.8% (w/v) yeast extract, 0.5% (w/v) polypeptone, 0.1% (w/v) K₂HPO₄, 0.02% (w/v) MgSO₄·7H₂O, 1% (w/v) Na₂CO₃, and 3% (w/v) NaCl. The alkaline protease was purified by 70% ammonium sulfate precipitation of the culture supernatant of Bacillus sp. DK1122, followed by CM-Sepharose chromatography. The molecular weight of the enzyme was estimated to be 27 kDa on the basis of SDS-PAGE. The optimum temperature and pH for the protease activity were 60℃ and pH 9.0, respectively. Addition of CaCl₂ increased the thermal stability of the purified protease, where 90% of protease activity was retained at 60℃ for up to 3 h. Consequently, it is expected that the alkaline protease from this study, exhibiting stability at pH 7–9 and 60℃, may be promising for application in the food and detergent industries.

• Microbiology and Biotechnology Letters
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• v.25 no.4
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• pp.403-407
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• 1997

Medium components for maximum activity of NAD$^{+}$-dependent formate dehydrogenase (EC 1.2.1.2; FDH) were optimized with a methanol-assimilating yeast Hansenula sp. MS-364, preserved by our laboratory. The maximum activity of the enzyme was obtained when the strain was cultivated at 30$circ$C for 24 hours in a medium containing methanol 3%(v/v), yeast extract 0.8%(w/v), K$_{2}$HPO$_{4}$, 0.1%(w/v), KH$_{2}$PO$_{4}$ 0.1%(W/V), MgSO$_{4}$, 7H$_{2}$O 0.05%(w/v), and the pH of the culture broth was adjusted at 5.0.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.3
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• pp.341-347
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• 2017

This study was carried out to investigate the characteristics and Vitamin $K_2$ (MK-7) productivity of Cheonggukjang fermented by Bacillus subtilis SRCM100757 depending on the inoculum concentration 0.5% (v/w), 1% (v/w) and 2% (v/w). The lowest moisture content and water activity were $53.7{\pm}0.6%$ and $8.39{\pm}0.09$ after fermentation for 72 hours at 2% (v/w). pH slowly became alkalized during fermentation, but there was no significant difference. Amino nitrogen content increased with time and the highest content was $580.8{\pm}1.9mg%$ after fermentation for 72 hours at 2% (v/w). Lightness (L value) and yellowness (b value) decreased with time, whereas redness (a value) hardly changed. MK-7 contents increased with time at each inoculum concentration. The highest content was $20.47{\pm}1.53$ after fermeatation for 72 hours at 2%(v/w) and there were no significant differences between 1%(v/w) and 2%(v/w) inoculum concentrations.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.3
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• pp.175-181
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• 2008

Cellolose nanoparticles loaded with retinyl palmitate were prepared by modified spontaneous emulsification solvent diffusion method. We used polysorbate 20, polysorbate 60, and PPG-26-Buteth-26/PEG-40 Hydrogenated castor oil as dispersion medium. The optimum condition for particle size of cellulose nanoparticles was 1w/v% ethyl cellulose with, 3w/v% polysorbate 60 solution. And The optimum condition for leading amount of retinyl palmitate of cellulose nanoparticles was 2w/v% ethyl cellulose with 1w/v% polysorbate 60 solution. Also, we found that this optimum condition can be applicable to other active compounds.

• Kyungpook Mathematical Journal
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• v.63 no.1
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• pp.123-129
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• 2023

For an ordered set W = {w₁, w₂, . . . , w_k} of vertices and a vertex v in a connected graph G, the k-vector r(v|W) = (d(v, w₁), d(v, w₂), . . . , d(v, w_k)) is called the metric representation of v with respect to W, where d(x, y) is the distance between the vertices x and y. A set W is called a resolving set for G if distinct vertices of G have distinct metric representations with respect to W. The minimum cardinality of a resolving set for G is its metric dimension dim(G), and a resolving set of minimum cardinality is a basis of G. The corona product, G ⊙ H of graphs G and H is obtained by taking one copy of G and n(G) copies of H, and by joining each vertex of the ith copy of H to the ith vertex of G. In this paper, we obtain bounds for dim(G ⊙ K₁), characterize all graphs G with dim(G ⊙ K₁) = dim(G), and prove that dim(G ⊙ K₁) = n - 1 if and only if G is the complete graph K_n or the star graph K_1,n-1.