• Journal of Applied Biological Chemistry
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• 제54권3호
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• pp.153-158
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• 2011

본 연구에서는 Bacillus subtilis JK-1의 생물계면활성제 생산을 위한 배양 특성을 조사하기 위하여 다양한 배양 온도와 배지의 pH, NaCl 농도에 따른 균주의 생장과 배양액의 pH, crude 생물계면활성제의 표면장력을 배양 시간대별로 측정하였다. B. subtilis JK-1은 $15-45^{\circ}C$와 pH 6-10, 0-10% (w/v) NaCl 농도의 환경에서 생장과 생물계면활성제 생산이 가능하였으며, 배양액의 pH는 중성 또는 약알칼리성으로 점차 변화 하였다. 생물계면활성제 생산은 pH 7.0의 초기 배지에서 $35^{\circ}C$, 48시간 동안 배양했을 때 최대였으며, 이 때의 표면장력은 24.0mN/m이었다. 그리고 배지 내 NaCl 농도가 0% (w/v)에서 10% (w/v)로 증가할수록 균주 생육도는 감소하였고, 최종 배양액의 pH는 약알칼리성에서 산성으로 변화하였으며, 표면장력 값은 증가하였다.

• 대한수의학회지
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• 제33권2호
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• pp.277-283
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• 1993

In the present study, observations were made on the life-history of Lymnaea viridis under laboratory conditions, involving incubation period of the eggs and their hatching rate, shell length of the newly hatched snails, sexual maturity, size of the snails when the snail produced the first egg-mass, the number of eggs in each egg-mass, egg-laying, ovipostion, growth rate of the snails, and longevity of the snail. At temperatures between $19.8^{\circ}C$ to $22.5^{\circ}C$, incubation period of the eggs occupied 10~12 days, and after beginning of hatching, all young snails emerged completely from the egg-mass within 5 days. The hatching rate was 88%. The average shell length of the newly hatched snails was about 0.064cm. The rate of growth was extraordinarily rapid under good laboratory conditions. When two snails were reared in one culture vessel($20{\times}15{\times}5cm$) with blue-green algae at about $22^{\circ}C$, snail growth was optimal, taking 37 days to reach 1.2cm in shell length. Sexual maturity reached in about 19 days. The size of the snails at sexual maturity was $0.78{\pm}0.05cm$ in length and $0.47{\pm}0.04cm$ in width. The first egg-masses produced were $0.59{\pm}0.22cm$ in length and $0.34{\pm}0.08cm$ in width, and contained 7~38 eggs. The eggs are usually laid in water. The egg-laying was affected by food and temperature. Snails fed with blue-green algae at about $22^{\circ}C$ produced larger egg-masses than the snails fed with fish food at about $26^{\circ}C$. Under conditions of continuous activity and growth, the maximum expectation of life appears to be 109~350(mean 230) days. And the shell length of snails at death were 1.39~1.64cm.

• 한국식품영양과학회지
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• 제30권5호
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• pp.806-813
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• 2001

천일염, 한주 소금, 구운 소금 및 죽염이 김치 발효에 중요한 영향을 미치는 미생물인 Leuconostoc mesenteroides, Lactobacillus plantarum과 산막효모인 Pichia membranaefaciens 및 식품오염의 지표균인 E. coli의 생육에 미치는 영향을 조사하였다. 각각의 소금을 3%, 5% 농도로 첨가하여 김치 발효 조건에 따라 배양 온도를 각각 1$0^{\circ}C$, 18$^{\circ}C$, 37$^{\circ}C$로 나누어 비교하였다. 그 결과 Leuconostoc mesenteroides는 배양 온도가 낮을수록, 소금 농도가 높을수록 성장이 저해되었으나 소금 종류별로는 특이할 만한 저해 효과는 나타나지 않았다. Lactobacillus plantarum도 마찬가지로 배양 온도가 낮을수록, 소금 농도가 높을수록 성장이 억제되었으며, 특히 18$^{\circ}C$, 5% 소금농도에서 죽염에 대해 저해 효과가 두드러졌고 1$0^{\circ}C$배양에서는 소금 종류와 농도에 관계없이 생육이 상당히 저조했다. Pichia membranaefaciens는 배양 온도에 관계없이 죽염에서 상당한 저해효과를 보였으며, 특히 18$^{\circ}C$, 5$^{\circ}C$ 소금농도에서는 전혀 자라지 못해 완전한 억제 효과를 보였다. E. coli도 다른 소금에 비해 1$0^{\circ}C$와 18$^{\circ}C$에서 죽염에 대해 저해 효과가 두드러졌다. 따라서 본 실험 결과 김치발효에도 어느 정도 관여하나 과다한 산 생성으로 김치의 가식기간을 단축시키는 Lactobacillus plantarum과 김치 표면에 산막을 형성하여 부패를 촉진시키는 Pichia membranaefaciens 그리고 식품오염의 지표균인 E. coli의 성장에 죽염이 다른 소금에 비해 상당한 저해 효과를 나타내었다.

• 한국양식학회지
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• 제10권4호
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• pp.449-456
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• 1997

담수산 윤충의 대량배양을 위한 기초연구의 일환으로 진해내수면연구소 야회사육지에서 micro-pipette을 이용하여 Brachionus calyciflorus를 분리하여, 피갑의 크기, 포란 수 등을 조사하였고, 온도별 배양시험을 수행한 결과 다음과 같은 결과를 얻었다. 1. 분리한 담수산 윤충인 B. calyciflorus 의 피갑의 크기는 두 가지로 S-type은 길이가 평균 $141.0\pm16.7\mu m$($110.1-182.5\mu m,\;n=44$),폭이 평균 $107.0\pm20.3 \mu m\;(75.3-152.3 \mu m, n=44$)이었으며, L-type은 길이가 $262\pm15.2\mu m(234.4-288.6 \mu m,\;n=20)$,폭이 $182.6\pm13.4\mu m \;(159.8-207.0\mu m, n=20)$이었다. 2. 배양시 개체당 포란수는 1개에서 11개까지 다양하였으며, 난의 장경은 대형난과 소형난으로 구분되었는데 S-type의 경우 1-2개 포란한 경우 장경 평균 범위가 85.7-107.8 $\mu m$ 이었으며 3개 이상 포란한 경우는 장경 평균의 범위가 55.1-65.2 $\mu m$이었다. 한편 L-type의 경우 1-3개 포란한 경우 장경 평균 범위는 104.9-121.8 $\mu m$로 대형이었고, 4개 이상 포란한 경우 62.8-89.1 $\mu m$ 범위로 소형난이어서 S-type의 난보다 비교적 큰 편이었다. 3. 온도별 실험구에서 최대 밀도에 도달한 시기는 4일째로 성장이 가장 양호한 실험구는 $25^{\circ}C$ 실험구로 평균 배양 밀도 583.9개체/$m\ell$로 최대이었으며, 22$^{\circ}C$ 실험구는 배양 밀도 421.3 개체/m$m\ell$로 최대 밀도에 달하였으며, $28^{\circ}C$ 실험구의 경우 배양 1일 후 평균 4.7개체/m$m\ell$로 급격히 감소한 후 3일째에는 3개체/m$m\ell$ 이하로 감소하여 성장이 극히 불량하여 배양조건으로 부적합하였다. 4. 일간 개체군 증가율은 $22^{\circ}C$ 실험구의 경우 배양 2일째에 가장 높아 0.802이었고, 다시 낮아진 다음 최대 밀도에 도달했던 4일째에 0.762로 회복되었으며, $25^{\circ}C$ 실험구의 경우 배양 3일째 0.964까지 점진적으로 높아진 후 감퇴되었다. 암컷 개체당 포란수는 $22^{\circ}C$ 실험구의 경우 배양 3일째 0.614로 가장 높았으며, $25^{\circ}C$ 실험구의 경우 배양 4일째로 0.772이었다.

• 생명과학회지
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• 제12권6호
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• pp.708-714
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• 2002

최근 들깨잎 주산지인 부산시 강동지역과 경남 밀양지역 하우스내의 들깨잎에 가장자리가 검게 변하고 마르는 증상을 띄는 병해가 발생되고, 심하면 잎 전체가 고사하는 병이 발생되었다. 이런 병반으로부터 병원성이 강하고 분생포자 형성이 많은 SD1 균주를 분리하여 병원균의 형태 및 배양적 특성을 조사한 결과 PDA 평판배지에서 $25^{\circ}C$, 암조건으로 배양할 경우 균사생장이 가장 왕성하였으며, 분생포자 형성량은 V8A 평판배지에서 가장 많았다. 또한 SD1 균주의 균사생장 적온은 $25^{\circ}C$, 분생포자 형성 적온은 3$0^{\circ}C$였으며, 분생포자 현탁액에 첨가한 영양원에 따른 분생포자 발아율과 발아관의 신장은 10% 토마토쥬스에서 가장 양호하였는데 24시간 후 발아율은 거의 100%였으며, 36시간 후 발아관 길이는 535.2$\mu\textrm{m}$로 PDB보다 1.4배정도 길었다. 또한 SD1 균주의 병원성을 검정한 결과 10% 토마토쥬스를 첨가한 분생포자 현탁액으로 접종할 경우 자연 발병된 병징과 동일하였으며 발병율도 100%로서 PDB 분생포자 현탁액에서는 60%, 살균수에서는 전혀 발병되지 않았다. 본 균주는 균총 형태와 색깔, 광학현미경을 이용한 형태적 특성과 몇 가지 배지 등을 이용한 배양적 특성 및 병원성 검정 결과에 따라 Alternaria alternata로 동정되었으며, 들깨 잎마름병으로 명명하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.802-806
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• 2005

The objective of this study was to determine the effects of processing method and rapeseed variety on ruminal and intestinal protein digestibility of rapeseed meal in steers. Intestinal amino acid digestibility was assessed with an in situ ruminal incubation and precision-fed rooster bioassay. In this experiment one traditional rapeseed meal sample (sample A, prepress extraction) and three double low rapeseed meal samples (sample B, prepress extraction, sample C, screw press and sample D, low temperature press) were placed in polyester bags(8 cm${\times}$12 cm) and suspended in the ventral rumen of steers for 16 h. The residues of in situ incubations were intubated to roosters. Total excreta were collected for 48 h after incubation and then desiccated and amino acid concentrations were determined. Results showed that in ruminal incubation the degradation rate of amino acid and crude protein was higher for traditional rapeseed meal sample A than for double low rapeseed meal sample B, but was much lower than for double low sample C and D. In the group of double low rapeseed meal samples, sample D processed by low temperature press had the highest degradation rate of amino acids in the rumen. For all amino acids, the digestibility of the residual protein as measured by the precision-fed rooster bioassay tended to be lower for sample B than for sample A, which had the same processing method with sample B, and in the group of double low rapeseed meals, sample B had similar digestibility of amino acid in residual protein to sample D and higher than that of sample C. However, although the total amino acid availability involving the digestibility of amino acids in the rumen and rooster bioassay of double low rapeseed meal sample D (low temperature press) was higher than those of the other three samples by 7 to 9 percent, there were no significant differences. Results indicated that processing method markedly affected ruminal and post ruminal amino acid digestibility of rapeseed meal when the temperature exceeded 110$^{\circ}C$. Rapeseed meal that had a high content of fiber was not suitable for dry heat treatment at higher temperatures or the amino acids digestibility in rumen and total availability of amino acids could be reduced. Results also suggested the variety of rapeseed meal had no significant effect on the digestibility and availability of amino acids.

• 한국어병학회지
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• 제11권2호
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• pp.143-150
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• 1998

바지락 조직과 주변 환경에 있는 세균의 특성과 분포를 여러 배지와 온도 그리고 생화학적 동정 kit를 사용하여 비교 분석하였다. 장내, 갯벌, 아가미 그리고 외부체액에 있는 미생물의 집락수는 사용한 BHIA, STA 그리고 SNA 배지에 영향을 받지 않는 것으로 나타났다. 그리고 $15^{\circ}C$ 배양조건에서의 증식속도는 $25^{\circ}C$와 $35^{\circ}C$의 조건에 비해 느린 것으로 나타났으나 총 세균 집락수는 $15^{\circ}C$에서의 것이 가장 높게 나타났다. 영양배지에서 자란 세균집락을 무작위적으로 선택배지에 옮기면 조직 시료를 직접 도말 한 경우에 비해 높은 비율로 집락형성을 하는 것을 보여 주었다. API 20E와 API 20NE를 사용하여 각 장기 또는 외부에 있는 세균의 종류를 동정한 결과 바지락 조직간에는 서로 유사한 종의 분포를 보이나 주위 환경이 되는 갯벌이나 외부체액에 있는 미생물군의 종류와는 다르게 나타났다. 바지락 주위의 갯벌이나 외부체액의 미생물군은 Pseudomonas 가 주종을 이루고 있는 조직내의 미생물군에 비해서 훨씬 높은 다양성을 보여 주었다. 이러한 결과는 바지락 조직이 주위 환경중의 세균에 대한 선택적 친화력이 있음을 의미한다고 할 수 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권3호
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• pp.439-446
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• 2014

Many studies on methane ($CH_4$) and nitrous oxide ($N_2O$) emissions from livestock industries have revealed that livestock production directly contributes to greenhouse gas (GHG) emissions through enteric fermentation and manure management, which causes negative impacts on animal environment sustainability. In the present study, three essential values for GHG emission were measured; i.e., i) maximum $CH_4$ producing capacity at mesophilic temperature ($37^{\circ}C$) from anaerobically stored manure in livestock category ($B_{0,KM}$, Korean livestock manure for $B_0$), ii) $EF_{3(s)}$ value representing an emission factor for direct $N_2O$ emissions from manure management system S in the country, kg $N_2O-N$ kg $N^{-1}$, at mesophilic ($37^{\circ}C$) and thermophilic ($55^{\circ}C$) temperatures, and iii) $N_{ex(T)}$ emissions showing annual N excretion for livestock category T, kg N $animal^{-1}$ $yr^{-1}$, from different livestock manure. Static incubation with and without aeration was performed to obtain the $N_2O$ and $CH_4$ emissions from each sample, respectively. Chemical compositions of pre- and post- incubated manure were analyzed. Contents of total solids (% TS) and volatile solid (% VS), and the ratio of carbon to nitrogen (C/N) decrease significantly in all the samples by C-containing biogas generation, whereas moisture content (%) and pH increased after incubation. A big difference of total nitrogen content was not observed in pre- and post-incubation during $CH_4$ and $N_2O$ emissions. $CH_4$ emissions (g $CH_4$ kg VS-1) from all the three manures (sows, layers and Korean cattle) were different and high C/N ratio resulted in high $CH_4$ emission. Similarly, $N_2O$ emission was found to be affected by % VS, pH, and temperature. The $B_{0,KM}$ values for sows, layers, and Korean cattle obtained at $37^{\circ}C$ are 0.0579, 0.0006, and 0.0828 $m^3$ $CH_4$ kg $VS^{-1}$, respectively, which are much less than the default values in IPCC guideline (GL) except the value from Korean cattle. For sows and Korean cattle, $N_{ex(T)}$ values of 7.67 and 28.19 kg N $yr^{-1}$, respectively, are 2.5 fold less than those values in IPCC GL as well. However, $N_{ex(T)}$ value of layers 0.63 kg N $yr^{-1}$ is very similar to the default value of 0.6 kg N $yr^{-1}$ in IPCC GLs for National greenhouse gas inventories for countries such as South Korea/Asia. The $EF_{3(s)}$ value obtained at $37^{\circ}C$ and $55^{\circ}C$ were found to be far less than the default value.

• 한국약용작물학회지
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• 제16권3호
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• pp.155-160
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• 2008

Ginsenosides have been regarded as the principal components, responsible for the pharmacological and biological activities of ginseng. Absorption of major ginsenosides at the gastrointestinal tract was extremely low, when ginseng taken orally. In order to improve the absorption and bioavailability, transformation of major ginsenosides into more active and valuable minor ginsenoside is much required. In this present study, We isolated a lactic acid bacteria Leuconostoc fallax LH3 from the Korean fermented food Kimchi, which have higher ${\beta}$-glucosidase activity. Using the ethanol precipitated curd enzyme of Leuconostoc fallax LH3, we investigated the biotransformation of ginsenoside Rd at different experimental condition to increase transformation. The maximum convertion was supported at 30 $^{\circ}C$ and decreased when temperatures increased. In order to optimize the effect of pH, the curd enzyme was mixed 20 mM sodium phosphate buffer (pH 3.5 to pH 8.0). Ginsenoside Rd was almost hydrolyzed between pH 7.0 and pH 9.0, but not hydrolyzed above pH 10.0. Ginsenoside Rd was hydrolyzed after 24 hrs incubation, but whereas the ginsenoside F2 was appeared from 36 hrs, and all ginsenoside Rd was transformed to F2 after the 60 hrs incubation. Based on this study, the curd enzyme of Leuconostoc fallax LH3 transformed the ginsenoside Rd at the 30$^{\circ}C$ and the pH optimum of 7.0 to 9.0 after the 60 hrs incubation time.

• 한국미생물·생명공학회지
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• 제25권1호
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• pp.89-95
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• 1997

The current processer of the textile wastewater treatment are mostly consisted of a combination of a physico-chemical and a biological treatment. The overall efficiency of these processes is, however, assessed to be fairly low. It is even worse during the summer season when temperature of the wastewater rises above 40$\circ $C. Therefore, a feasible process of the textile wastewater treatment which can work efficiently at higher temperatures was investigated in this work. We used a bench scale reactor consisted of one 4 liter anaerobic and one 8 liter aerobic tank, and the thermophilic symbiotic PVA degraders, Pasteruella hemolytica KMG1 and Pseudomonas sp. KMG6 that had been isolated in our laboratory. In the preliminary flask experiments, we observed that the thermophilic symbiotic PVA degraders could not grow in the wastewater substrate. Then, we isolated the mutant strains by acclimating the KMG1and KMG6 strains to the wastewater medium. The mutant symbionts (KMG1-1 and KMG6-1) were isolated through 6 times successive transfers into the fresh wastewater medium after 5 days culture for each. The mutant strains obtained grew well in the mixed medium composed of 75% wastewater and 25% synthetic medium, and supplemented with 0.5% PVA as a sole carbon source. During the culture for 14 days at pH 7.0 and 40$\CIRC $C, the bacteria assimilated about 89% of the added PVA. The symbionts degraded equally well all the PVA substrates of different molecular weight (nd=500~30000). In contrast to the flask experiments, in the reactor system the mutant strains showed very low levels of the PVA and COD removal rates. However, the new reactor system with an additional aerobic tank attained 82% removal rate of COD, 94% of PVA degradation and 71% of color index under the conditions of 5% inoculm on the tank 2, incubation temperature of 40$\circ $C, dissolved oxygen level of 2~3 mg/l and retention time of 30 hours. This result ensures that the process described above could be an efficient and feasible treatment for the PVA contained textile wastewater at higher temperatures.