• KSBB Journal
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• v.9 no.4
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• pp.372-377
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• 1994

To improve L-lysine yield, pyrimidine base analogue(6-azauracil)-resistant mutants were isolated from Corynebacterium glutamicum KFCC10672 Among them the best producer, C. glutamicum CH0516, was selected and tested for L-lysine production in a $7\ell$ fermentor. It was found that the product yield obtained with C. glutamicum CH0516 was higher than that of the parent strain by 3%. In order to elucidate the gain in productivity with the 6-azauracil-resistant mutant enzymatic kinetic parameters such as aspartokinase(AKase) and aspartate carbamoyltransferase (ATCase) were measured. The Km values of AKase with C. glutamicum KFCC10672 and CH0516 were 200.0 mM and 166.7 mM and those of ATCase were 0.13 mM and 0.27 mM, respectively. However, the specific enzyme activities of AKase of C. glutamlcum KFCC10672 and CH0516 were $3.89{\times}10^{-1}$ units/mg and $4.78{\times}10^{-1}$ units/mg, and those of ATCarse were 2.20 units/mg and 1.84 units/mg, respectively. It appears that some increase in product yield with C. gluramicum CH0516 is likely due to the increased Akase activity and decreased ATCase activity.

• Food Engineering Progress
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• v.14 no.3
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• pp.229-234
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• 2010

The applicability of a commercial enzymatic time-temperature integrator (TTI) for monitoring spoilage of ground beef was investigated under isothermal storage condition at different temperatures. The volatile basic nitrogen (VBN) value was used as a spoilage index for ground beef. The time taken to reach the spoilage of ground beef stored at 4, 10, 15, 20, and ${25^{\circ}C}$ were 168, 114, 60, 48, and 24 hrs, respectively. However, these quality losses of beef were not coincided with the endpoints of the three different C-type TTIs (C-1, C-4, and C-7). In order to match the TTI response to the quality loss of beef, some ingredients such as enzyme and substrate solutions were extracted from C-1TTI and remixed with different amount of them in the tubes to constitute the modified TTIs. The responses of the modified CM-1 TTI were very close to the quality loss of beef stored at 20 and ${25^{\circ}C}$, but not at other temperatures tested. The response of the other modified CM-2 TTI was only matched to the quality loss of beef stored at ${15^{\circ}C}$. Therefore, systematic kinetic studies of food spoilage and the TTI response are required to apply the TTI as a quality indicator for a specific food.

• Tuberculosis and Respiratory Diseases
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• v.52 no.6
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• pp.608-615
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• 2002

Background : ADA is an enzyme found in most cells, and is involved in purine metabolism, but its chief role concerns the proliferation and differentiation of lymphocytes, especially T-lymphocytes. For that reason ADA has been looked on as a marker of cell-mediate immunity, which is the key mechanism of the tuberculous pleural effusion. Thus, the pleural fluid ADA activity is increased in the tuberculous pleural effusion. Age associated immune decline is characterized by decreases in both B and T-lymphocyte function and the former may be largely a result of the latter. Therefore, the pleural fluid ADA activity would be lower in old rather than in young, patients with tuberculous pleural effusion. We studied the relationship between age, and pleural fluid ADA activity, in patients with tuberculous pleural effusion. Materials and Methods : In the 46 patients with tuberculous pleural effusion enroll in this study, the pleural fluid ADA activities were measured by means of an automated kinetic method. Results : The mean age of the patients was $53.0{\pm}22.0$ years, with a male to female ratio of 30:16. The patients were divided into two groups, young patients, regarded as < 65 and old regarded as ${\geq}65$ years with 28 and 18 patients, respectively. The pleural fluid ADA activity in both groups show significant differences : $99.4{\pm}22.6$ IU/L(young patients) Vs. $75.8{\pm}30.9$ IU/L(old patients)(p<0.05), but a negative correlation with age (r=-0.311, p<0.05). Conclusion : Although pleural fluid ADA activity was not adequately increased, tuberculous pleural effusion, in older patients, would have to be considered clinically suspicious tuberculous pleural effusion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.164-170
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• 1985

Yellowish modified wool, dithiocarbamate(DTC) wool, was synthesized by partial hydrolysis in 0.2 N-NaOH reacting with carbon disulfide to use as ${\alpha}-amylase$ immobilization matrix. ${\alpha}-amylase$ was immobilized reacting with sulfide group of DTC-wool by covalent binding within 1 hour. 0.5 gram of this preparation, $DTC-wool-{\alpha}-amylase$, contained 150 ug of enzyme protein and its specific activity was about 90% of the native one. General properties of $DTC-wool-{\alpha}-amylase$ were a little different from optimum temperature, optimum pH, heat stability, kinetic constants and activation energy. An apparent Michaelis constant and maximum velocity of $DTC-wool-{\alpha}-amylase$ were 5.56 mg/ml and 0.37 mg/ml. $min^{-1}$ respectively, while activation energy was 16.6 kcal/mole.