• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.154-163
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• 1989

This studies were designed to improve the productivity of L-lysine by protoplast fusion and immobilized system of fusants using strains of Brevibacterium flavum ATCC 21528, Brevibacterium lactofermentum ATCC 21086 and Corynebacterium glutamicum 820. Mutants were isolated with concentration method of $300{\mu}g/ml$ penicillin-G after treatment of $250{\mu}g/ml$ N-methyl-N-nitro-N-nitrosoguanidine. B. flavum $37-2(Hos^-,\;Kan^r,\;AEC^r)$, B. lactofermentum $6-2(Ile^-,\;Val^-,\;Str^r,\;AEC^r)$ and C. glutamicum 57-5$(Met^-,\;Thr^-,\;Rif^r,\;AEC^r)$ were isolated from mutants. Protoplasts were induced by being incubated with $500{\mu}g/ml$ lysozyme of lysis solution for 6 hr and the ratio of protoplast formation and regeneration were ranging from 97-99% and 33-37%, respectively. Fusion frequencies of fusants of BBFL 21, BCFG 37 and BCLG 59 were shown in the range from $1.25{\times}10^{-6}\;to\;5.83{\times}10^{-7}$ under the optimum conditions. The fusant BBFL 21 showed the highest productivity of $411.1\;ng/ml{\cdot}hr$ L-lysine in the lysine productivity broth at $30^{\circ}C$ for 72hr. In the immobilization systems, fusant BBFL 21 was employed in various polymer matrices such as sodium alginate, polyacrylamide, agar and ${\alpha}-carrageena$. The immobilization of sodium alginate showed the highest productivity of $413\;ng/ml{\cdot}hr$ L-lysine in the batch system. Continuous fermentation of immobilization system by using tube fermentor was produced the highest productivity $416.7\;ng/ml{\cdot}hr $ L-lysine under optimum condition.

• Tuberculosis and Respiratory Diseases
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• v.50 no.4
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• pp.473-483
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• 2001

Background : There are only a few studies regarding the causes of treatment failure for tuberculosis. Therefore, this study aimed to determine the causes of intractable tuberculosis. Methods : M. tuberculosis, differentiated MOTT (Mycobacterium Other Than Tuberculosis) were isolated, and the RFLP (Restriction fragments length polymorphisms) pattern was analyzed from 204 patients with pulmonary tuberculosis and 53 suffering from neck tuberculosis. The IL-$1{\beta}$, IL-12, $^*1\;IFN{\gamma}$ and $^*2\;TNF{\alpha}$ blood levels were measured. All patients were regularly followed for 18 months after treatment. Results : There was no correlation between the RFLP patterns of M. tuberculosis treatment failure. From the 204 cases, 31.9% were intractable. The characteristics of patients with intractable tuberculosis were old age, being male and recurrent cases. The causes of treatment failure were identified as follows ; a decrease in the IL-12(59.4%) concentration, drug resistant strain(54.7%), irregular medication(15.4%), MOTT(6.2%) and a heavy infection(4.6%). The causes of all cases of intractable tuberculosis could be investigated. The IL-12 concentration in the blood was significantly lower in the intractable cases, where it disclosed a maximum sensitivity(64.7%) and specificity(75.4%) at 165.0 pg/mL. Most of the 53 cases of neck node tuberculosis were treated successfully. Therefore, we were unable to analyze the cause of treatment failure. Conclusion : A decrease in the blood IL-12 concentration and drug resistant strains were identified as the most significant causes of treatment failure for tuberculosis. In Korea, infection by clusters were prevalent, but no difference in the clinical course between clusters and non-clusters could be found.

• Applied Biological Chemistry
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• v.19 no.4
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• pp.219-226
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• 1976

To meet the need of protein feed and fine more efficient ways of returning waste to resources, we have carried out the study of the production of yeast for foods and feeds from the corn starch cake. The present study includes the method for acid-hydrolysis, the selection of yeast capable of utilizing hydrolyzate of the corn starch cake, and culture condition of Candida tropicalis under the liquid culture and the semisolid culture. Obtained results were as follows. 1. Hydrochloric acid was more excellent on the hydrolysis of the corn starch cake than sulfuric acid, and the yield of sugar was maximum, 57.2%, when the corn starch cake was hydrolyzed with 1.0% of hydrochloric acid at 2.0kg/cm for 30 minutes. 2. As the acid solution content was increased, more sugar was liberatedfrom the mixture, until the acid solution-substrate ratio reached 10:1. Beyond this point, no further increase was observed. To prepare the cultural medium of semisolid fermentation, a acid solution to substrate ratio of 3:1 appeared to be optimum. 3. Out of 6 yeast strains, Candida tropicalis had excellent growth on the hydrolyzate of the corn starch cake, and optimum temperature and initial pH were $30^{\circ}C$ and 6.0 respectively. 4. Optimum liquid medium of Candida tropicalis is ures 0.3%, potassium phosphate monobasic 0.15g and magnesium sulfate 0.04g in 100ml of the hydrolyzate of the corn starch cake, while optimum semisolid medium is ammonium chloride 0.4g, potassium phosphate monobasic 0.1%, magnesium sulfate 0.04%. 5. Candida tropicalis could assimilate the sugar in the hydrolyzate up to more than 88.75%, and a yield of dry yeast reached 19.13% to the corn starch cake under the liquid culture. 6. Compared to the that of the untreated corn starch cake, the cellulose content of the semisolid fermented cake decreased by 3.76% to 14.7%, whereas dry yeast contents increased by 13.89%.

• Food Science and Preservation
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• v.21 no.1
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• pp.121-128
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• 2014

This study was conducted in order to investigate the change of isoflavone composition (glycoside and bio-active aglycone), and to evaluate the quality characteristics of Cheonggukjang, which was prepared by different bacillus strains. After the 48-hour fermentation, the contents of daidzein, genistein, and glycitein in the Bacillus subtilis HJ18-3 have significantly increased up to approximately $89.06{\pm}3.59$, $10.36{\pm}0.28$, and $101.37{\pm}3.67ug/g$, respectively. The contents of daidzein, genistein, and glycitein in the Bacillus subtilis KACC 15935 were $38.88{\pm}5.39$, $12.58{\pm}2.14$, and $80.13{\pm}0.71ug/g$, respectively. The original content of daidzein was 3.96 ug/g, while genistein and glycitein were not measured. However, the contents of daidzen and genistein in HJ18-3 and in KACC 15935 were decreased. The ${\alpha}$-Amylase and cellulase activities of Chungkookjang in HJ18-3 were higher than in the KACC 15935. The contents of Chungkookjang in HJ18-3 were $29.70{\pm}11.66$ and $4861.3{\pm}388.07unit/g$, respectively. The amino type nitrogen contents and ammonia type nitrogen contents of Chungkookjang in KACC 15935 were higher than in the HJ18-3. These results suggested that it could be used to increase the bioactivity via fermentation with the Bacillus subtilis possessing a ${\beta}$-glucosidase activity with a view towards the development of functional foods.

• Food Science and Preservation
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• v.23 no.6
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• pp.797-803
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• 2016

In this study, we investigated the effect of fermentation conditions on the amylolytic and proteolytic activities of Aspergillus luchuensis strain 74-5 and Aspergillus oryzae strain 75-2, which are used in the preparation of the starter culture, for Takju (Korean traditional rice wine). The starter culture was optimized using different conditions, such as inoculum size, inoculation temperature, and incubation time. The enzyme activities under each condition were measured. In the A. luchuensis strain 74-5 starter culture, the ${\alpha}-amylase$ and glucoamylase activities increased, however the activity of acidic protease decreased as the diluent to starter culture ratio increased. In the A. oryzae 75-2 starter culture, all enzyme activities were maintained at a higher level even at 5% inoculation ratio. Higher enzyme activities were observed in the middle range of inoculation temperature (35, $40^{\circ}C$), than in the lower range (20, $30^{\circ}C$). Enzyme activity in the starter culture varied with incubation time, however it was the highest at 144 and 120 hr, respectively, for A. luchuensis strain 74-5 and A. oryzae strain 75-2. The spore count of the starter culture was approximately $2{\times}10^7$ during fermentation, out of which contamination by aerobic bacteria was about $3{\times}10^3$. The results suggested that the starter culture of each strain could be used as an inoculum for fermentation. However, we needs to conduct further research for the selection of suitable diluting agents as well as drying methods to reduce the contamination by aerobic bacteria, while retaining the enzyme activity.

• Korean Journal of Poultry Science
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• v.39 no.3
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• pp.245-252
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• 2012

This study was carried out to investigate the performance of laying period of two-crossbred of Korean native chickens for producing laying hens. A total of four hundred eighty female 2-crossbred chicks that restored strains and were aboriginal at National Institute of Animal Science. There were four crossbreds (4 replications/crossbred, 30 birds/replication) as A) C strain ${\times}$ Y strain, B) C strain ${\times}$ L strain, C) C strain ${\times}$ G strain, and D) C strain ${\times}$ W strain, respectively. There were no significant difference on age at first egg among crossbreds (P>0.05). Egg weight and body weight of B crossbred at first egg was higher than other crossbreds (P<0.05). Body weight of B crossbred was the highest 20 to 72 weeks (P<0.05), and C and D crossbreds were lower compared to A and B crossbreds (P<0.05). Average feed intake of B crossbred was the highest among crossbreds (P<0.05), and that of A crossbred was higher compared to C and D crossbreds (P<0.05). Weekly feed intake of four crossbreds decreased from 50 weeks. Weekly egg weight of B crossbred was the highest and that of D crossbred was the lowest among crossbreds (P<0.05). Feed conversion ratio of A and B crossbreds was lower than that of C and D crossbreds. Hen-house egg production of C crossbred was the highest among crossbreds until 26 weeks old (P<0.05), but there was no significant difference among crossbreds from at the age of 26 weeks (P>0.05). Hen-day egg production decreased after at the age of 38 weeks. Weekly egg production of A and B crossbreds was higher compared to C and D crossbreds at the age of 68~72 weeks (P<0.05). These results suggested the basic data on the record of laying period of 2-crossbreed Korean Native Chickens for producing laying hens.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.263-270
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• 2013

The vent sexing and the auto-sexing by using sex-linked traits are general sexing methods of day-old chicks. Currently, the feather sexing which is based on the differences in the feather characteristics at hatching is the representative sexing method of chicken, because the late-feathering is sex-linked trait. The feather sexing can be used if the breed has dominant feathering gene (K) in maternal and recessive gene ($k^+$) in paternal. Therefore it is necessary to identify the association of feathering genes and quantitative traits in chickens. In this study, we investigated the influence of the rate of feathering on productive traits in Korean Native Chicken. In results, there was no significant difference between early-feathering chickens and late-feathering chickens in reproductive performance such as fertility and hatchability. Livability, body weights, egg production, egg weight and egg quality also did not significantly differ between early- and late-feathering chickens. Age at first egg was the only trait of those tested in which significant difference was observed. The early-feathering chickens laid eggs 3 days earlier than late-feathering chicken. As a result, there is no influence of feathering phenotypes on productive performance in Korean Native Chickens. Consequentially, establishing the feather sexing strain is available using the Korean Native Chicken breed without considering of the effect of feathering genes on productive traits.

• The Korean Journal of Mycology
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• v.24 no.1 s.76
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• pp.38-48
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• 1996

The survival or colonization of beneficial organsisms and suppression of root rot of ginseng (Panax ginseng) by two distinct bacteria, Pseudomonas cepacia, Bacillus cereus and three mycorrhiza in pot soil were investigated and compared with uninoculated root. In separate inoculation, colonization of roots by P. cepacia was maintained at 6.25 (log cfu/g root) during growth for 10 days under pot culture conditions comparing to $5.62{\sim}6.19$ by mixed treatment with other organisms. Colonizations of P. cepacia were gradually decreased from 6.25 (log cfu/g root) in 10 days growth to 3.01 (log cfu/g root) in 270 days incubation period. This reduction was also investgated in combination treatments by B. cereus or F. solani. The numbers of Fusarium spp. were colonized high number in rhizosphere soil from 3.33 to 3.67 (log cfu/g root) in control within $10{\sim}60$days after treatment of pathogen F. solani, but it's numbers were markedly decreased in 270 days cultivation of plant from 3.33 to 1.02 (log cfu/g root) after treatment. In treatment of beneficial strains of P. cepacia and B. cereus, P. cepacia significantly suppressed the development of root rot from 4.3 in control to 1.2 in treatment, whereas B. cereus alone had no effect on the rate of disease suppression. The disease index $(1.8{\sim}2.3)$ in combination of two bacteria was reduced in plants inoculated with both P. cepacia and B. cereus comparing to the index (4.3) of control. As an effect of inoculation with mycorrhiza on disease suppression, suppression of root rot by F. solani was reduced to $1.2{\sim}1.6$ in disease index in treatment of Glomus albidum and Acaulospora longular comparing to 4.3 of control. In the treatment of bacterial strain P. cepacia and mycorrhizal fungus Glomus albidum, the disease suppression was apparent to 1.2 and 1.2 comparing to 4.3 of control in disease index respectively.

• Food Science and Preservation
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• v.11 no.4
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• pp.550-556
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• 2004

In the present study, we investigated the antimutagenic and cytotoxic effects of Acer ginnala Max. bark extract on S. typhimurium TA98, TA100 and cancer cell lines with Ames test and SRB assay, respectively. They were extracted with methanol and then fractionated using hexane, chloroform, ethyl acetate, butanol, and water to obtain the fractions. The inhibition rate of methanol ($200\;{\mu}g/plate$) of Acer ginnala Max. bark extract in the Salmonella typhimurium TA100 strain showed $83.3\%$ against the mutagenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). In addition, the suppression of methanol extract with same concentration of in the Salmonella typhimurium TA98 and TA100 strains showed $80.3\%\;and\;92.7\%$ inhibition against 3-amino-1,4-dimethyl-5H-pyrido-(4,3-b)indol (Trp-P-1), respectively. The cytotoxicity effects of Acer ginnala Max. bark extract against the cell lines with human lung carcinoma (A549), human gastric carcinoma (AGS), human hepatocellular carcinoma (Hep3B) and human breast adenocarcinoma (MCF-7) were inhibited with the increase of the extract concentration. The treatment of 1.0 mg/mL Acer ginnala Max. bark methanol extract of methanol showed strong cytotoxicities of $77.3\%,\;90.4\%,\;88.9\%,\;and\;83.7\%$ against A549, AGS, Hep3B and MCF-7, respectively.

• Food Science and Preservation
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• v.22 no.6
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• pp.920-925
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• 2015

The microbial composition in Nuruk, a Korean cereal fermentation starter, is a critical factor for the quality and organoleptic properties of traditional alcoholic beverages. This study was aimed at monitoring the compositional change and enzyme activity of culturable lactic acid bacteria (LAB) in two types of Nuruk fermented at different temperatures. All culturable LAB were isolated at various time points (0, 3, 6, 10, 20, and 30 days) and identified by 16S rRNA sequencing. In traditional Nuruk type A (TN-A), which was fermented at $36^{\circ}C$, the population of total culturable LAB during the fermentation period was between $10^4$ and $10^5$ log CFU/mL. On the other hand, the LAB population in traditional Nuruk type B (TN-B) fermented at $45^{\circ}C$ (primary fermentation for 10 days) and $35^{\circ}C$ (secondary fermentation for 20 days) was $10^2$ log CFU/mL; however, these bacteria could not be detected after 6 days. Major LAB strains were identified in both Nuruk types: (1) from the MRS-culture of TN-A, Pediococcus pentosaceus at 3-30 days; (2) from MRS-culture of TN-B, P. pentosaceus at 3 days and Enterococcus hirae at 6 days. The protease activities of the dominant LAB isolated from the TN-A and TN-B cultures were within the ranges of 0.64~1.03 mg/mL and 0.74~0.81 mg/mL (tyrosine content), respectively, whereas the ${\alpha}$-amylase activities were 0.75~0.98 mg/mL and 0.78~0.79 mg/mL (amylose content), respectively.