• 신재생에너지
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• 제20권1호
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• pp.175-181
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• 2024

This study analyzed the hydrogen conversion rate and microbial community in conjunction with changes in carbohydrate concentration during hydrogen fermentation using food waste, and presented comprehensive research results for the condition 80 g Carbo COD/L, which showed the highest efficiency with a carbohydrate removal rate of 98.1% and a hydrogen conversion rate of 1.76 mol H₂/mol. The microbial community analysis found that Clostridium sp., widely known as a hydrogen-producing microorganism, was released in 80 g Carbo COD/L and confirmed that it was a dominant species at 98.1%. Conversely, in 100 g Carbo. Under COD/L conditions, Leuconostoc sp. showed the maximun prevalence, which is believed to hinder hydrogen production.

• Journal of Biosystems Engineering
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• 제24권2호
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• pp.107-114
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• 1999

To find the best combustion conditions in the heavy oil burner kinetic viscosity of heavy oil A, B and C at different temperature range, from 40 to 140$^{\circ}C$, and the droplet sizes of the heavy oils at different temperature and pump pressure were measured. And, combustion characteristics were investigated under the different conditions : two different heavy oil and three different oil temperature. At temperature of 70, 100, 130$^{\circ}C$ the kinetic viscosity of heavy oil A and B are 7.9, 5.7, 4.3 and 30.4, 13.7, 7.9cSt, respectively. The greatest and smallest viscosity were 7,455 cSt at C oil on 27$^{\circ}C$ and 4.26cSt at A oil on 140$^{\circ}C$. The magnitude of viscosity difference between at 100$^{\circ}C$ and 140$^{\circ}C$ under 6 cSt in cases of A and B oil, but more than 30cST on C oil. Of the droplet sizes, the biggest and smallest droplet size in A oil were 98$\mu\textrm{m}$ at oil temperature of 130$^{\circ}C$(4.3cSt), pump pressure of 1.57MPa and 72$\mu\textrm{m}$ at 70$^{\circ}C$(7.9cSt), 2.35MPa, respectively. It appeared that as spraying pressure increased the droplet size decreased, however, no distinct differences were found in the effects of kinetic viscosity on the droplet sizes of the test range. The best combustion performance was observed when droplet size, spraying pressure and oil temperature were 73$\mu\textrm{m}$, 2.35MPa and 70$^{\circ}C$ producing CO2 of 13.1%, CO of 13ppm and flue gas temperature of 250$^{\circ}C$ in A oil combustion For B oil, it was100$^{\circ}C$, 2.35MPa, 52$\mu\textrm{m}$, producing CO2 of 10ppm and flue gas temperature of 260$^{\circ}C$. In general, it appeared that better combustion results were observed in the smaller droplets produced burner condition.

• Applied Biological Chemistry
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• 제32권4호
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• pp.435-440
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• 1989

Alkaline protease를 생산하는 Bacillus subtilis를 $100{\mu}g/ml$ NTG 처리하여 $Arg^-,\;Try^-,\;His^-\;Ade^-$ 영양요구성주를 분리하였다. 원형질체 형성은 대수증식기의 균체를 lysozyme $200{\mu}g/ml$로 $42^{\circ}C$에서 $10{\sim}30$분간 처리하였을 때 약 99%였다. 재생배지에 0.3M sodium succinate, polyvinylpyrrolidone 2.0%, casamino acid 0.5%, $10mM\;MgCl_2$ 및 $20mM\;CaCl_2$를 첨가했을 때 재생율은 25.2% 였다. 원형질체 융합은 40%(w/v)의 PEG 6,000 용액을 상온에서 $1{\sim}5$분간 처리시 약 $2{\sim}8{\times}10^{-5}$의 융합빈도를 얻을 수 있었다.

• 한국식품영양과학회지
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• 제24권5호
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• pp.790-795
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• 1995

응집제를 생산하는 미생물은 토양시료로 부터 분리하여 그 중 응집활성이 높은 1 균주를 선택하여 분류학적 위치를 조사한 결과, Arcuadendrop sp.으도 동정되었으며 본 균주를 Arcuadendron sp. TS-49로 명명하였다. 응집제 생산 최적배지는 3% glucose, 0.2% yeast extract, 0.1% $NH_4Cl$, 0.05% $MnSO_4$, 0.01% $MgSO_4$ (pH 7.0)의 경우가 가장 우수하였으며, 배양 온도 및 배양 pH는 $30^{\circ}C$, pH 7.0일 때가 최적이었다. 최적 배양조건하에서 4~5일간 배양시 응집제 생산량이 최대에 도달하였으며 배양 시간의 경과와 더불어 응집활성은 급격히 감소하는 현상을 보여 생분해성이 우수함을 나타내었따. 이때의 응집제 생산량은 screening 배지에 비해 거의 10배 정도로 향상되었으며, 각종 microorganism과 suspended solid에 대한 응집작용을 검토한 결과, 정도의 차이는 있으나 모든 공시물질에 응집활성을 나타내었다.응집제의 조성을 검토하기 위해 각종 정성 test를 행한 결과, 당과 단백질이 검출되어 일종의 glycoprotein 임이 확인되었다.

• 한국식품영양과학회지
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• 제31권5호
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• pp.754-759
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• 2002

공업적으로 광범위하게 이용되고 있는 protease 중 중성 영역에서 최적의 활성을 갖는 중성 protease에 대한 연구의 일환으로, 토양으로부터 protease의 생성능이 우수한 10여 균주를 순수 분리하였으며, 이들 중에서 protease의 활성 이 가장 우수한 PANH765를 최종 선별하였다. 이 균주의 형태학적, 배양학적, 생리학적 및 생화학적 특성을 조사하여 Bergey의 세균 분류서의 색인에 따라 체계적으로 분류한 결과, Bacilius subtilis 또는 그 유연균으로 동정되어 분리균을 Bacilius .Subtilis PA-NH765로 동정하였다. B. subtilis PANH-765 균주에 의한 protease의 최적 배지 조성은 2.0% glucose, 1.0% yeast extract, 0.2% ammonium nitrate, 0.02% ferrous sulfate 및 0.02% di-potassium hydrogen phosphate이었으며, 최적 생산 조건은 배양온도 ,3$0^{\circ}C$, pH 7.0, 진탕 속도 150 rpm이었다. 이 조건에서 초기 균체량을5%(w/v)접종하여 배양하였을 때 시간에 따른 효소의 최대 활성은 배양 ,36시간일 때 6.34 U이었다.

• KSBB Journal
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• 제19권4호
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• pp.295-300
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• 2004

해양유래미생물에서 gelatin 분해능이 우수한 균주 Vibrio vulnificus CYK 279H를 이용하여 최적 효소활성조건을 검토하였다. 온도와 초기 pH는 $25^{\circ}C$, 7.5에서 높은 것으로 나타났으며, 단당, 이당, 다당류를 첨가하여 탄소원의 영향에서는, 0.3% (w/v) galactose 에서, 유$.$무기 질소원으로는 0.6% (w/v) yeast extract와 4.0% (w/v) gelatin, 0.2% (w/v) (NH$_4$)$_2$SO$_4$에서 효소활성이 가장 높게 나타났다. 염 농도로는 2.0% (w/v) NaCl, 금속이온은 Fe$^{2+}$를 첨가하였을 때 효소활성이 증가되었다. 선정된 최적배양조건에서 Vibrio vulnificus CYK 279H를 배양한 결과, 18 h 배양시 73 Unit/1로 기본배지 20 Unit/1보다 활성이 3.7배 증가한 것으로 확인되었다.

• 한국환경보건학회지
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• 제35권5호
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• pp.393-401
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• 2009

We isolated and identified a microorganism which was excellent for ammonia oxidation in the biological control of ammonia gas in odor producing materials from organic composting. The isolated strain was tested for growth characteristics and ammonia elimination efficiency under various conditions of temperature, pH, carbon concentration and ammonia concentration. The strain was isolated from a culture broth used in a $NO_2$ producing test with Griess-Ilosvay reagent. The results of 16S rRNA sequence from the isolated strain by using BLANST (Basic Local Alignment Search Tool) and confirming RDP (Ribosomal Database Project II) and ERRD (The European Ribosomal RNA Database) indicate that the strain is related to Delftia sp. UV-Spectrophotometer (Shimadzu, UVmini-1240) was used as a microbial growth test by measuring turbidity on OD660nm and ammonia concentration was measured by Spectrophotometer (HACH, DR-4000). The optimum growth culture conditions of the ammonia oxidizer Delftia sp. were $30^{\circ}C$, pH 7, glucose concentration 1.00% and $(NH_4)_2SO_4$ 0.5 g/l. Ammonia elimination efficiency was over 94% under the same conditions.

• KSBB Journal
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• 제29권3호
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• pp.131-138
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• 2014

In this study, we isolated two novel chitinase producing bacterial strains from yellow loess samples collected from Jullanamdo province. The chitinase producing bacteria were isolated based on the zone size of clearance in the chitin agar plates. Both of them were gram positive, rod ($2{\sim}3{\times}0.3{\sim}0.4{\mu}m$), spore-forming, and motility positive. They were facultative anaerobic, catalase positive and hydrolyzed starch, gelatin, and casein. From the 16s rRNA gene sequence analysis, the isolates were labeled as Bacillus licheniformis KYLS-CU01 and B. licheniformis KYLS-CU02. The isolates showed higher extracellular chitinase activities than B. licheniformis ATCC 14580 as a control. The optimum temperature and pH for chitinase production were $40^{\circ}C$ and pH 7.0, respectively. Response Surface Methodology (RSM) was used to optimize the culture medium for efficient production of the chitinase. Under this optimal condition, 1.5 times higher chitinase activity of B. licheniformis KYLS-CU02 was obtained. Extracellular chitinases of the two isolates were purified through ammonium sulfate precipitation and anion-exchange DEAE-cellulose column chromatography. The specific activities of purified chitinase from B. licheniformis KYLS-CU01 and B. licheniformis KYLS-CU02 were 7.65 and 5.21 U/mg protein, respectively. The molecular weights of the two purified chitinases were 59 kDa. Further, the purified chitinase of B. licheniformis KYLS-CU01 showed high antifungal activity against Fusarium sp.. In conclusion, these two bacterial isolates can be used as a biopesticide to control pathogenic fungi.

• 말소리와 음성과학
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• 제5권3호
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• pp.73-81
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• 2013

Coda in the word-medial position plays an important role in acquisition of our speech. Accuracy of the coda in the word-medial position is important as a diagnostic indicator since it has a close relationship with degrees of disorder. Coda in the word-medial position only appears in condition of connecting two vowels and the sequence causes diverse phonological processes to happen. The coda in the word-medial position differs in production difficulty by the initial sound in the sequence. Accordingly, this study aims to examine the tendency of producing a coda in the word-medial position with consideration of an optional phonological process in spontaneous speech of three and four year old children. Data was collected from 24 children (four groups by age) without speech and language delay. The results of the study are as follows: 1) Sonorant coda in the word-medial position showed a high production frequency in manner of articulation, and alveolar in place of articulation. When the coda in the word-medial position is connected to an initial sound in the same place of articulation, it revealed a high frequency of production. 2) The coda in word-medial position followed by an initial alveolar stop revealed a high error rate. Error patterns showed regressive assimilation predominantly. 3) The order of difficulty that Children had producing codas in the word-medial position was $/k^{\neg}/$, $/p^{\neg}/$, /m/, /n/, /ŋ/ and /l/. Those results suggest that in targeting coda in the word-medial position for evaluation, we should consider optional phonological process as well as the following initial sound. Further studies would be necessary which codas in the word-medial position will be used for therapeutic purpose.

• Journal of Animal Science and Technology
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• 제51권5호
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• pp.427-432
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• 2009

본 연구에서는 xylanase, mannanase를 생산하는 미생물균주를 분리하기 위해 1차로 토양 및 낙엽 등에서 곰팡이 균주를 약 50여주 분리하였으며, 1차 선발된 균주로부터 xylanase, mannanase를 생산하는 미생물 분리를 위해 xylanase 생성균주 선별배지, mannanase 생성균주 선별배지에 single colony를 접종한 후 clear zone이 생기는 15종의 균주를 2차 선발하였다. 2차 선발된 균주를 개별적으로 배양하여, DNS 방법을 활용하여 xylanase, mannanase 효소활성을 측정하여 6종의 균주를 선발하였다. 선별된 균주는 액상배양에서 생산한 xylanase, mannanase 효소활성이 각각 0.9~1.6 unit/mL, 0.2~0.4 unit/mL 범위로 나타났다. 이 중 결과가 좋은 3종을 선정하여 고상배양으로 배양한 균주의 xylanase, mannanase 효소활성은 각각 103.7~220.0 unit/g, 20.1~40.3 unit/g으로 분석되었다. 선별된 3종의 균주중 xylanase, mannanase 효소활성이 각각 197.3 unit/g, 39.9 unit/g으로 가장 높은 E-3 균주를 최종적으로 선발하였다. 최종으로 분리한 E-3 균주는 형태학적 특징과 DNA 염기서열을 비교한 결과 Aspergillus niger와 99% 일치하였다.