• Applied Biological Chemistry
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• v.41 no.5
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• pp.337-341
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• 1998

The morphological and cultural characteristics of alkalophilic Coryneform bacteria TU-19 were investigated at various pHs. This bacterium showed normal growth pattern at $pH\;9.0{\sim}10.0$, but the cell growth was completely inhibited at extreme pH (12.0 or more). Interestingly, at pH 8.0 the morphology of the bacterial cells seems to form convoluted filaments during the exponential growth phase while at pH 10.0, the optimal pH for the growth of this organism, the bacteria grew with variable paired or single forms, and straight rods during growth stages. Growing in alkaline media $(pH\;9.0{\sim}11.0)$, it adjusted the pH of the culture media to around pH 8.5 by itself.

• Applied Biological Chemistry
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• v.9
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• pp.91-96
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• 1968

1. Two strains of Aspergilli producing acid resistant amylase were isolated from air. The strain $U^{-1}$ and $U^{-2}$ were similar to Asp. usamii tan type mutant in the morphological characteristics. 2. The influence of cultural pH for production of amylase were investigated in the suface culture, it was different each other in the cultural optimum initial pH. The activity of acid resistant amylase produced by strain $U^{-1}$ was higher than that of strain $U^{-2}$. The acid resistance was increased by culturing in lower pH. 3. The lower initial pH ($U^{-1}$ pH 4.0, $U^{-2}$ pH 2.0) was better than neutral (pH 6.0) for the production of amylase and growth of them. The effect of low initial pH for the production of amylase was not to accelerate but caused by change of pH in the cultural process, in the range of this experiment.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.10a
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• pp.248.2-248
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• 1979

식초산 발효 실험을 통하여 다음과 같은 결과를 얻었다. 1. 자연에서 초산균 52균주를 분리하고 그중 식초산 농도 5.5% 이상되는 초산균 CAU-4, CAU-15, CAU-17, CAU-46, 4균주를 선별하였다. 2. 정치배양과 진탕배양을 실시한 결과 산생성랑은 진탕배양에서 월등한 효과를 보였다. 3. 유기태 질소원의 첨가시 peptone을 0.4%까지 증가를 보였고, yeast extract는 0.1~0.2%가 최적량이고 그 이상은 산량이 감소되었다. 4. $NH_4NO_3의$ 자화성을 조사한 결과 CAU-17만이 자화하지 못하였고, 무기태 질소원으로서는 $(NH_2)_2CO가$ 가장 좋았다. 5. 무기염류는 $KH/_2PO_4,$ $MgSO_4.7H_2$ O 0~0.1% 첨가하여 약간의 효과를 보았다. 6. Glucose의 첨가량별 산량의 증가는 0.25% 첨가시 0% 첨가시 보다 증가를 보인 반면 1% 첨가시는 오히려 감소하였다. 7. 초발 alcohol농도가 낮을수록 유도기와 대수기가 단축되며 10%이상에서는 4균주 모두 산을 생성하지 못하였다. 8. 초발산도가 높을 경우 유도기가 길어지고 산생성량이 줄어 들었다. 9. 초산균의 배양온도는 $30^{\circ}C,$ $35^{\circ}C에서$ 산생성 속도가 가장 빨랐다. 10. 발효시 산생성량에 따른 세균수의 증가는 접종후 2~3일 사이에 가장 많았다. 11. 초산의 증가와 더불어 균체량은 증가하였고 pH는 약간색 감소하나 PH는 2.5이하로는 내려가지 않았다. 12. alcohol 잔량은 발효 개시 후 5 ~6일의 정지기에 가장 낮았다.

• Microbiology and Biotechnology Letters
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• v.11 no.1
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• pp.15-21
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• 1983

This experiment was carried out to optimize the condition for the enzyme production by selected strain in the basal medium, to purify the enzyme and to characterize the purified enzyme. The results obtained were as follows. 1. The optimal conditions for the $\beta$-galactosidase production were initial pH 7.0 and temperature $65^{\circ}C$. 2. Enzyme was induced by the addition of lactose and galactose, and it was intracellular enzyme. 3. The purified enzyme was obtained with the increased level of activity approximately 28.5 folds as compared with crude enzyme and the yield of 15.2% by means of DEAE-Cellulose column chromatography, Sephadex G-150 gel filtration 4. $\beta$-galactosidase from final step of purification showed a sing1e protein band on polyacrylamide gel disc electrophoresis. 5. The optimal temperature and pH of the purified enzyme were $65^{\circ}C$, pH 6.5 for the hydrolysis of lactose.

• Korean Journal of Microbiology
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• v.22 no.4
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• pp.257-263
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• 1984

A strain producing an extracellular cytosine deaminase was isolated from soil samples. The enzyme obtained from the strain possessed the substrate specificity to both cytosine and 5-fluorocytosine. From the results of its morphological, cultural, physiological, and biochemical properties, the strain was thought to be the genus Arthrobacter. Therefore, it was named as Arthrobacter sp. JH-13. The composition of optimum medium for the enzyme formation was 0.5% of peptone, 0.5% of meat extract, 0.5% of soluble starch, and 0.1% of KCl. The optimum pH for the enzyme formation was 8.0. When the microoganism was cultured aerobically in the above medium, enzyme production reached at maximum in 54 hours at $30^{\circ}C$.

• Journal of the East Asian Society of Dietary Life
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• v.6 no.2
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• pp.195-204
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• 1996

This study was conducted to enhance the shelf-life of Kimchi and to make the unique taste of Kimchi by fermentation control. Kimchis, Prepared by win baechu soaked in 10% salt solutions containing 0.2-0.3% organic acids (OS-Kimchi), acetic acid, citric acid (CA-Kimchi), lactic acid, its mixtures and formic acid+acetic acid+fumalic acid+malic acid+citric acid(FAFMC), were examined for pH, titratable acidify, sensory evaluation, the number of total microbe and lactic acid bacteria, content of organic acids and texture during fermentation at 1$0^{\circ}C$. The decrease of pH and the increase in acidity, CA-Kimchi showed lower than those of control and various OS-Kimchi. Total microbe, lactic acid bacteria, content of lactic acid of CA-Kimchi were lower than those of control. The hardness of CA-Kimchi measured instrumentally was higher than that of control. Sensory scores of CA-Kimchi were also lower than those of control, so the Kimchi maintained good crispness and overall taste.

• Biomedical Science Letters
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• v.6 no.3
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• pp.209-221
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• 2000

The purpose of this study was to investigate the practical availability of pretense production that can be used at home after isolating Serratia sp.2000-1 which produced extracellular pretense from clinical specimen. Basic production conditions and partial enzymatic characteristics of pretense produced by Serratia sp. 2000-1 was as follows: The kind and concentration of carbohydrate, nitrogen and metal salts for optimal enzyme production condition were each identified as the concentration of 1.5% glucose, 2.0% CSP, and 0.1% CaCl$_2$, and the optimal temperature, time and initial pH for culture were each 3$0^{\circ}C$, 72 hours, and pH 8.0. The final enzymatic yeild that was purified by 3 steps with ammonium sulfate precipitation (45~80%), DEAE-cellulose column chromatography, and Sephadex G-200 gel chromatography was 14.4%, and enzyme inactivity rate increased approximately 291314s. The optimal temperature and pH for purified pretense activity were 35$^{\circ}C$ and pH 7.0~8.0, and purified pretense activity was relatively stable by 4$0^{\circ}C$ at pH 6~10 for 30 min, however heating at 6$0^{\circ}C$ for 30 min, it liminated detectable pretense activity. The pretense activity was activated by $Mg^{2+}$, $Ba^{2+}$, $Ca^{2+}$, Mn$^{2+}$, but inactiviaed by Hg$^{2+}$, Ag$^{2+}$, Cu$^{2+}$, and the pretense activity was inhibited strongly by SDS among enzyme activity inhibitors. Further study is required to evaluate the practical availability of pretense production that can be used at home by isolating Serratia sp. from more clinical specimen and examining pretense more in details.

• The Korean Journal of Mycology
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• v.24 no.3 s.78
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• pp.223-227
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• 1996

The effects of addition of dried apple pomace to sawdust substrate on the growth of Flammulina velutipes were investigated during the period of 2 years $(1994{\sim}1995)$. Dried apple pomace used in this study consisted of 44.6% C, 0.54% N, 0.16% CaO, 0.16% $P_2O_5$, 0.11% MgO and 1.29% $K_2O$ (pH 4.4). The addition of 15% apple pomace (v/v) increased the yield of the mushroom fruitbody by 9%, and period of primordia formation was similar regardless of the treatments. In economical analysis, the addition of 15% apple pomace (v/v) increased 29% compared to the control treatment in relative income.

• The Korean Journal of Mycology
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• v.9 no.3
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• pp.129-132
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• 1981

Thle experiments were carried out to select the highest yield and good quality of the oyster mushroom (Pleurotus sp.) strain for brooding material sources. The strains used covered 6 from 4 countries, No. 2063, 2078 and 2093 were collected from Korea, No. 2068 introduced from Japan, No. 2091 from Germany and No. 2095 from Taiwan. Some characteristics of the strains are as follows. 1) The optimum temperature for strains, 2091, 2093 and 2063 of P. ostreatus was $30^{\circ}C$, it ranged from 25 to $30^{\circ}C$ for the others. 2) The optimum moisture content were 70% for strain 2068, 80% for strains 2093, 2095 and 2091, 75% for other strains. 3) The optimum pH of the mycelial growth were at pH 6.0 for strains 2093 and 2068, pH 6.0 and pH 8.0 for other strains. 4) The days from spawning to budding was the shortest in strain 2095 and the yield was the highest in 2091, $64.4kg/3.3m^2$on the rice straw cultivation.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.10a
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• pp.208.1-208
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• 1978

Phenol 성 물질이 함유된 산업폐수의 처리와 phenol을 탄소원으로 하는 균체를 이용할 목적으로 공업폐수의 오이로부터 phenol 자화능이 우수한 효모 균주를 선택하여 이 균의 생육에 미치는 환경요인을 조사하였다. 초발 pH 3.5~4.5에서 $35^{\circ}C$ 경우 자화능이 가장 좋았으며 $HgC1_2$ phenylhydrazin $10^{-3}$M 농도에서 완전히 자화능을 잃었다. 배양기 중의 질소원으로 $KNO_3,$ $(NH_2)_2CO가$ 가장 좋았으며 yeast extract 0.01% 첨가하므로써 가장높은 발육효과를 보았다. Phenol을 연속적으로 90시간까지 5회 feeding하며 계속적인 균체증식과 phenol 소모를 보았으며 한편 본균이 catechol, resorcinol도 자화할 수 있다는 점도 알았다.