• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.504-509
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• 1989

Fermentation condition of Streptococcus lactis IFO 12007 for nisin production was examined. The optimal glucose concentration was 60g/ι. The pH and temperature optimum were 6.5 and 31$^{\circ}C$, respectively. The maximum nisin activity in batch culture was 2000IU/$m\ell$. The fermentation quotients after 7 hours of fermentation in batch culture were; specific glucose uptake rate:0.59g/g/h , specific nisin productivity: 34924IU/g/h, product yield: 5944IU/g, growth yield:0.24, biomass:4.81g/ι. The specific growth rate was affected by pH and temperature and the activation energy for growth was 1.35kcal/mole. pH control was essential for nisin production. Fed-batch culture using 20g/$\ell$ glucose medium produced 1420IU/$m\ell$ after 14 hours. The continuous culture could be operated at below 0.38h$^{-1}$ for nisin production. The steady state nisin concentration and specific nisin productivity were 740IU/$m\ell$ and 45000IU/g/h. The growth yield and maintenance energy were 0.144 and 207mg glucose/g-cell/h.

• Applied Biological Chemistry
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• v.20 no.2
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• pp.175-181
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• 1977

Lysosomal enzyme latency was demonstrated for hydrolases from porcine leukocyte by suspending sediment sfrom differential centrifugation in 0.125 to 0.250 M sucrose. Specific activities pH optima and activation energies were determined for hydrolases distributed in various sedimentation fractions and for enzymes solubilized by n-butyl alcohol extraction. Specific activities of the hydrolases revealed the heterogeneity of the Iysosomal fractions relative to enzyme content. pH optima identified the enzyme as acid hydrolases with optima for cathepsin D and aryl sulfatase also at pH 6.8. Activation energies of some hydrolases were low revealing that these enzymes could function efficiently during low temperature aging of meat.

• Korean Journal of Veterinary Research
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• v.44 no.3
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• pp.399-405
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• 2004

Haemophilus somnus, Mycoplasma bovis and Pasteurella multocida were responsible for respiratory diseases in bovine. Methods for identifying these bacteria had poor sensitivity and specificity. In this paper, PCR assays were applied for rapid identification of H. somnus, M. bovis, P. multocida B:2 and P. multocida capsular types. The specific PCR products were amplified from H. somnus, but not from other bacteria. Ten-fold diluted H. somnus were mixed with P. multocida and then the mixed cultures were inoculated on agar plates. After incubation, PCR was performed with harvest from agar plates and could detect as few as 3.4 CFU/ml of H. somnus. The primers MboF and MboR produced an amplification product unique to M. bovis and sensitivity of PCR was as low as 100 pg of DNA. Only serotype B:2 of P. multocida, the causal agent of haemorrhagic septicemia in bovine, was specifically amplified in PCR among the 16 reference serotypes. The multiplex capsular PCR typing for P. multocida was produced the P. multocida specific product as well as the capsular serogroup-specific product. The present PCR assays should be useful for the rapid identification of bacterial pathogens from bovine respiratory diseases.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.191-195
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• 2004

Drug delivery systems that are based on pectin have been studied for colon specific delivery using the specific activity of colon microflora. The aim of this study was to design a novel method of manufacturing pectin microspheres without oils and surfactants and to investigate the potential use of the pectin microspheres as an oral colon-specific drug carrier. The pectin microspheres were successfully formed using the spray drying method and crosslinking with calcium chloride. From the crosslinked pectin microspheres, indomethacin (IND) release was more suppressed than its release from non-crosslinked microspheres. In a low pH (pH 1.4) environment, the pectin microspheres released IND at an amount of about 18${\pm}$2% of the total loaded weight for 24 h while the release rate of IND was stimulated at neutral pH (pH 7.4). IND release from the pectin microspheres was increased by the addition of pectinase. The results clearly demonstrate that the pectin microspheres that were prepared by the spray drying and crosslinking methods are potential carriers for colon-specific drug deliveries.

• Journal of Life Science
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• v.21 no.11
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• pp.1565-1572
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• 2011

Eye-specific lactate dehydrogenase (EC 1.1.1.27, LDH) $C_4$ isozyme in the eyes of greenlings (Hexagrammos otakii) was successfully purified by affinity chromatography and continuous-elution electrophoresis. The molecular weight of the purified eye-specific LDH $C_4$ isozyme was 154.8 kDa, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Optimal pH for enzymatic reaction of the eye-specific LDH $C_4$ isozyme was pH 8.5. $K^{PYR}_m$ value of the purified eye-specific LDH $C_4$ isozyme was $1.88{\times}10^{-5}$ M using pyruvate as a substrate. These results indicate that we must consider pH when measuring eye-specific LDH $C_4$ isozyme activity. The eye-specific LDH $C_4$ isozyme had a higher binding affinity for the substrate as a pyruvate than LDH A4 isozyme. Antibodies produced against the purified eye-specific LDH $C_4$ isozyme may be used in the diagnosis of several human diseases and in comparative physiological studies of fishes.

• Journal of the Korean Ceramic Society
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• v.25 no.3
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• pp.193-200
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• 1988

The starting materials were aluminum hydroxide prepared by precipitation method at the conditions of pH values; 7, 9, 10 and 11. The properties of alumina powder on heat-treatment were studied. After dehydrating structural water from amorphous aluminum hydroxide, the first formed phase was amorphous alumina and its specific surface are was decreased. The specific surface area was increased by dehydration of structural water from aluminum hydroxides except amorphous aluminum hydroxide. The specific surface area was increased with increase of the ratio of A1OOH to $A1(OH)_3$ in the region of transition aluminas. The rate of transition from aluminum hydroxide to alpha alumina occurred in the order of 7, 10, 9 and 11 of pH values. The morphology of alpha alumina powders was skeleton particles remaining outer shape of aluminum hydroxide. Both the elevation of heat-treatment temperature and the transition toalpha alumina decreased specific surface area and brought about the growth of particles.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.223-229
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• 2003

The purpose of this work was to perform the characterization of NAD(P)H-nitroreductase isolated from Stenotrophomonas sp. OK-5 capable of degrading 2,4,6-trinitrotoluene (TNT). Initially, NADP(H)-nitroreductase by a series of purification processes including ammonium sulfate precipitation, DEAE-sepharose, andQ-sepharose was prepared. From samples harvested from fraction collector, three different fractions (I, II & III)having the enzyme activity of NAD(P)H-itroreductase were detected. Specific activities of three fractions I, II,and III of NAD(P)H-nitroreductase were determined to approximately 5.06 unit/mg, 4.95 unit/mg and 4.86 unit/mg, and concentrated to 10.5, 9.8, and 8.9-fold compared to crude extract, respectively. Among these three fractions,the fraction I of NAD(P)H-nitroreductase demonstrated the highest specific activity in this experiment. Several factors affecting on the enzyme activity of NAD(P)H-nitroreductase (fractions I, II & III) were investigated.The optimum temperature of all NAD(P)H-nitroreductase (fractions I, II & III) was 30oC, and the optimal pH was approximately 7.5. Metal ions such as Ag+, Cu2+, Hg2+ inhibited approximately 80% enzyme activity of all NAD(P)H-nitroreductase, and the enzyme activities were decreased about 30-40% inhibition in the presence of Mn2+ or Ca2+. However, Fe3+ showed stimulatory effect on the enzyme activity. The molecular weights of NAD(P)H-nitroreductase (fractions I, II & III) were measured about 27 kDa on the SDS-PAGE.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.69-76
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• 2013

Specific growth rate and removal rate of nitrogen and phosphorus of Chlorella sorokiniana, Chlorella vulgaris, Senedesmus dimorphus those are able to metabolite mixotrophically and have high nitrogen and phosphorus removal capacity were examined. Based on the results, one microalgae was selected and conducted experiments to identify the operating factors such as pH and aeration rate. The specific growth rate and phosphorus removal rate of C. sorokiniana significantly presented as $0.29day^{-1}$ and 1.65 mg-P/L/day, while the nitrogen removal rate was high as 12.7 mg-N/L with C. vulgaris. C. sorokiniana was chosen for appropriate microalgae to applying for wastewater treatment system and was cultured in pH ranged 3 to 11. High specific growth rate and removal rate of nitrogen and phosphorus were shown at pH 7 as $0.71day^{-1}$, 7.61 mg-N/L/day, and 1.24 mg-P/L/day, respectively. The specific growth rate examined with aeration rate between 0 and 2 vvm (vol/vol-min) highly presented as $1.2day^{-1}$ with 1.5 ~ 2 vvm, while the nitrogen removal rate was elevated with 0.5 vvm as 9.43 mg-N/L/day.

• KSBB Journal
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• v.17 no.3
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• pp.307-310
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• 2002

In order to obtain high density seed cells for biofiltration, we studied batch and fed-batch culture of P. putida. Studies were carried out to find optimum fermentation conditions such as pH, concentration of glucose and agitation speed. Specific growth rate of P. putida was dependent on agitation speed and a high rpm of 300 was necessary to carry out the efficient aerobic growth of P. putida. Specific growth rate was highest at pH 7. Feeding glucose and yeast extract continuously at the initial growth phase was the most effective way to get high cell density of P. putida.

• Journal of Life Science
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• v.14 no.4
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• pp.708-715
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• 2004

The lactate dehydrogenase (EC 1.1.1.27, LDH) in liver of Lempetra japonica was purified in buffer of affinity chromatography. The liver-specific $C_4$ isozyme of Gadus macrocephalus was purified by heat treatment, affinity chromatography, and DEAE-Sephacel chromatography. The liver-specific $C_4$ isozyme was eluted in a buffer containing NAD+ and was coeluted with $B_4$isozyme in plain buffer of affinity chromagraphy. Liver-specific $C_4$ isozyme in G. macrocephalus was the most thermostable, and$B_4$isozyme was more stable than $A_4$. The LDH in the fraction of pH 7.45 purified from the liver of L. iaponica by chromatofocusing was more inhibited by pyruvate than purified LDH. The optimum pH of the LDH isozyme in the liver of L. japonica was 7.5 and that of liver-specific$C_4$ isozyme was 8.5. The LDH in liver of L. japonica made complexes more with antibody against Coreoperca herzi$A_4$ and liver-specific $C_4$ than with that against eye-specific $C_4$. Therefore, the structure of the LDH in liver of L. japonica might be similarly evolved to that of subunit A and liver-specific $C_4$ isozyme in liver tissue of G. macrocephalus. The evolution rate of subunit C is faster than that of subunit A. LDH in liver of L. japonica has not one isozyme but isozymes and it was also found out to have not only subunit A and B but also subunit C.