• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.643-648
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• 2005

Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid, accurate method of evaluating some chemical constituents in cereal grains and forages. If samples could be analyzed without drying and grinding, then sample preparation time and costs may be reduced. This study was conducted to develop robust NIRS equations to predict fermentation quality of corn (Zea mays) silage and to select acceptable sample preparation methods for prediction of fermentation products in corn silage by NIRS. Prior to analysis, samples (n = 112) were either oven-dried and ground (OD), frozen in liquid nitrogen and ground (LN) and intact fresh (IF). Samples were scanned from 400 to 2,500 nm with an NIRS 6,500 monochromator. The samples were divided into calibration and validation sets. The spectral data were regressed on a range of dry matter (DM), pH and short chain organic acids using modified multivariate partial least squares (MPLS) analysis that used first and second order derivatives. All chemical analyses were conducted with fresh samples. From these treatments, calibration equations were developed successfully for concentrations of all constituents except butyric acid. Prediction accuracy, represented by standard error of prediction (SEP) and $R^2_{v}$ (variance accounted for in validation set), was slightly better with the LN treatment ($R^2$ 0.75-0.90) than for OD ($R^2$ 0.43-0.81) or IF ($R^2$ 0.62-0.79) treatments. Fermentation characteristics could be successfully predicted by NIRS analysis either with dry or fresh silage. Although statistical results for the OD and IF treatments were the lower than those of LN treatment, intact fresh (IF) treatment may be acceptable when processing is costly or when possible component alterations are expected.

• 한국미생물·생명공학회지
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• 제24권1호
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• pp.92-100
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• 1996

For the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(P(3HB-co-3HV)) from butyric acid and valeric acid, 10 strains of bacteria capable of producing P(3HB-co-3HV) were isolated from soil. Among them, the strain HJ-067 showed the best ability of producing P(3HB-co-3HV), and was indentified as a Azotobacter sp. For the production of P(3HB-co-3HV), the optimum concentrations of butyric and valeric acid were 3.0g/l, respectively. The most effective nitrogen source was $(NH_4)_{2}SO_4$ at an optimum concentration of 0.75g/l, which was equivalent to 21.36 in C/N ratio. Deficiency of the cationic metal ions ($Zn^{2+},\;Co^{2+},\;Mn^{2+}$) in the proguction medium had stimulating effect on P(3HB-co-3HV) accumulation, especially in the manganese. deficient medium. The optimum temperature for P(3HB-co-3HV) production was 27$^{\circ}C$ and the optimum initial pH was 7.0. Under the optimum conditions, 1.82g/l of P(3HB-co-3HV) and 3.00g/l of dry biomass were produced after 36 hour cultivation, and the P(3HB-co-3HV) yield and HV% were 60.60% (w/w), 15.92%, respectively.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2011년도 학술발표회
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• pp.191-191
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• 2011

우리나라의 수질 관리는 점오염원 관리에 집중되어 왔다. 수계의 수질이 크게 향상되지 않는 이유는 점오염원의 관리가 엄격히 수행되고 있는 가운데 비점오염원의 영향이 큰 것으로 판단되었다. 본 연구에서는 수문수질 모의가 가능한 SWAT (Soil and Water Assessment Tool) 모형을 이용하여, 비점오염원 저감을 위한 BMP (Best Management Practice) 시나리오를 작성하여 비점오염 부하량의 저감효과를 모의하였다. SWAT 모형의 적용성 평가를 위해 충주댐 유역 ($6,585.1km^2$)을 대상으로 민감도 분석을 통해 최적의 유출 및 유사관련 매개 변수를 선정하였으며, 1998년 부터 2003년까지의 기간 동안 일별 유출, 월별 수질자료에 대한 보정 및 검증을 실시하였다. 전체 17개 소유역에 대한 검보정에 의해 산정된 수질자료인 TN (Total Nitrogen), TP (Total Phosphorus) 그리고 sediment의 부하량을 파악하여 소유역별 TN, TP, Sediment 오염부하특성을 파악하였고, 이에 대하여 선정한 7개의 BMP 시나리오를 소유역의 오염 특성에 맞게 적용하였다. 선정한 BMP 시나리오로는 Streambank stabilization, Porous gully plugs, Recharge structures, Conservation tillage, Terrace, Contour farming 그리고 Manure incorporation이 있고 각 시나리오는 흐름에서의 침전물 감소, 단기간의 토양침식 저감, 지하수양의 증가, 경작지의 침식감소, 지표유출 저하, 흐름에서의 영양물질 감소를 목적으로 최적의 매개변수를 설정하였다. 이상의 결과를 종합적으로 고찰해 볼 때 SWAT 모형은 실측자료를 바탕으로 비점오염에 의한 하천수질 모의가 가능하며, 이 결과를 가지고 BMP시나리오를 적용하여 비점오염 저감에 따른 하천수질 개선을 기대할 수 있다.

• 한국균학회지
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• 제26권4호통권87호
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• pp.458-465
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• 1998

사과탄저병균, Glomerella cingulata에 선택적으로 항균활성이 있는 세균을 분리한 후 형태 및 생리화학적인 특성을 기준으로 동정하여 Pseudomonas sp. DGUM 5051로 명명하였다. 분리균의 생장을 위한 최적 pH와 온도는 각각 6.0과 $30^{\circ}C$이었고, 최적 항균활성을 나타내는 pH와 온도는 각각 7.0와 $24^{\circ}C$이었다. 사용한 복합배지 중 생장 및 항균활성에 있어서는 Brucella, Brain heart infusion과 LB배지가 우수하였다. Mineral salts 배지에 유일 탄소원, 질소원 및 인산원으로 각각 Sucrose, $KNO_3$ 및 $K_2HPO_4$를 첨가하였을 때 우수한 항균활성을 나타내었다. Pseudomonas sp. DGUM 5061의 항균활성은 배양 12시간 경과 후에 나타났다.

• 미생물학회지
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• 제16권4호
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• pp.170-179
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• 1978

By the successive enrichment culture, more than 250 methanol-utilizing bacteria were isolated from various samples such as soil, waste water and sewage. Two strains of which were selected and tentatively identified as Acinetobacter sp. and Pseudomonas sp. experiments were carried out to determine the growth conditions for the higher biomass yield and to demonstrate the difference to protein composition dependent upon carbon sources of these two species. the results were as follows ; 1. the optimum pH was determined as 8 in the both species. The optimum temperature in Acinetobacter sp. was $25^{\circ}C{\sim}30^{\circ}C$ and pseudomonas sp. was $30^{\circ}C-35^{\circ}C$. The optimum initial concentration of mthanol was determined as 1-2% in Acinetobacter sp. and 2-3% in pseudomonas sp. 2. The optimum concnetrations of nitrogen source, micro-elements, and vitamins such as biotin and thiamine-HCl in Acnetobactar sp. were 1g $(NH_4)_3SO4,\;1{\sim}3mg\;Mn^{++},\;4mg\;Fe^{++},\;10{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine-HCl per liter medium. In the Pseudomonas sp., 2g $(NH_4)_3SO4,\;1mg\;Mn^{++},\;trace\;amounts\;of\;Fe^{++},\;5{\mu}g\;biotin,\;and\;100{\mu}g$ thiamine HCl per liter were effective. Maximum biomass yield was 2.5g/l in Acinetobacter sp. and 4.8g/l in Pseudomonas sp. 3. Protein composition of the two strains exhibited that alkai-labile protein was higher than alkali-stable protein. In Pseudomonas sp., the contents of acid soluble fraction and alkali-stable protein of the cells grown in the methanol medium were higher than in sucrose medium. On the other hand, in Acinetobacter sp., alkalilabile protein of the cells grown in sucrose medium was higher than in methanol medium.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권5호
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• pp.408-413
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• 2006

We assessed the ability of a Pseudonocardia sp. from soil samples to bioconvert vitamin $D_3$. The optimal culture conditions for the bioconversion of vitamin $D_3$ to active $1{\alpha}$,25-dihydroxyvitamin $D_3$ were investigated by varying the carbon and nitrogen sources, the metal salt concentrations, the initial pH, and the temperature. Microbial transformations were carried out with the addition of vitamin $D_3$ dissolved in ethanol. They were sampled by extraction with methanol-dichloromethane and the samples were examined by HPLC. Optimum culture conditions were found to be 0.4% yeast extract, 1% glucose, 3% starch, 1% fish meal, 0.2% NaCl, 0.01% $K_2HPO_4$, 0.2% $CaCO_3$, 0.01% NaF, and pH 7.0 at $28^{\circ}C$. The optimal timing of the addition of vitamin $D_3$ for the production of calcitriol by Pseudonocardia autotrophica ID9302 was concurrent with the inoculation of seed culture broth. Maximum calcitriol productivity and the yield of bioconversion reached a value of 10.4mg/L and 10.4% respectively on the 7th day in a 75L fementer jar under the above conditions.

• KSBB Journal
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• 제31권3호
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• pp.158-164
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• 2016

Plant growth promoting (PGP) hormones, which are produced in a small quantity by bacteria, affect in plant growth and development. PGPs play an important role on the crop productivity in agricultural field. In this study, a photosynthetic bacterial strain producing the PGP was isolated from paddy soil. Bacterial isolate was gram negative, rod-shaped and motility positive. From the 16s rRNA gene sequence analysis, the isolate was identified as Rhodobacter capsulatus PS-2. The mass cultivation of R. capsulatus PS-2 was optimized by considering of the carbon, nitrogen and inorganic salt sources. Optimal medium composition was determined as Na-succinate 4.5 g, yeast extract 5 g, $K_2HPO_4$ 1 g, $MgSO_4$ 5 g, per liter. From the result of 500 L fermentation for 2 days using the optimal medium, the viable cells were $8.7{\times}10^9cfu/mL$. R. capsulatus PS-2 strain produced the carotenoid and indole-3-acetic acid (IAA). The carotenoid extraction and quantitative analysis were performed by HCl-assisting method. Total carotenoid contents from R. capsulatus PS-2 culture broth were measured as $7.02{\pm}0.04$ and $6.93{\pm}0.05mg/L$ under photoheterotrophic and chemoheterotrophic conditions, respectively. To measure the productivity of IAA, colorimetric method was employed using Salkowski reagent at optical density 535 nm. The results showed that the highest content of IAA was $197.44{\pm}5.92mg/L$ in the optimal medium supplemented with 0.3% tryptophan.

• 한국산림과학회지
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• 제94권5호통권162호
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• pp.302-306
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• 2005

Litterfall and nutrient inputs were measured in even-aged coniferous plantations (a 31-year-old Pinus rigida and a 31-year-old Larix leptolepis) on a similar site condition in the Forest Practice Research Center, Gyeonggi Province. Litterfall was collected monthly from circular littertraps (collecting area: $0.50m^2$) for three years between April 1997 and February 2000. Average total annual litterfall was significantly higher for pine (5,802 kg/ha/yr) than for larch (4,562 kg/ha/yr) plantations. Needle litter in both plantations accounted for about 63% of total litterfall. Litterfall in the larch was distributed as follows: needle > other leaf > branch > miscellaneous > bark, while it was needle > miscellaneous > other leaf > branch > bark in the pine plantation. There was no temporal variation in needle litter, other leaf and bark during the 3 year study period. The concentrations of all nutrients (N, P, K, Ca, Mg) in needle litter were significantly higher in the larch than in the pine plantations. The annual nutrient concentration of needle litter in the larch varied among the years, whereas no year variation of needle litter was in the pine except for phosphorus (P). Nitrogen (N) and P inputs by needle litter were significantly higher for larch than for pine plantations established on a similar soil. The differences in N and P inputs were attributed to lower nutrient concentration in pine needle litter compared with larch needle litter, not to total needle litter mass. Annual inputs of nutrient in both plantations were not significantly different among years except for K of the larch although there was yearly different in needlefall mass and nutrient concentration during the 3-year observed period. The results indicate that the mechanisms of litterfall and nutrient inputs vary considerably between pine and larch plantations established on a similar site condition.

• 한국작물학회지
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• 제8권1호
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• pp.83-89
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• 1970

각종 재배조건 및 저장기간이 고구마 전분함량에 미치는 영향을 구명코저 신미 품종을 공시하여 삽식기별 수수기별 시비량별 토성별 저장기간별로 구분 시험을 실시하였든바 요약하면 다음과 같다. 1. 5월 15일 삽식에 비하여 만식일수록 괴근수량 및 전분함랴은 감소되었고 특히 6월 5일 이후의 삽식에서 급격히 감소되었으며 괴근수량의 감소정도에 비하여 전분함량의 감소정도는 더욱 심하였다. 2. 10월 5일 적기수확에 비하여 조기수확일수록 괴근수량 및 전분함량은 감소 경향이였고 8월 25일 이전 조기수확은 괴근수량 37~45% 전분함량 5~7%의 감소를 보였다. 3. 시비량에 따라서 전분함량은 차이가 많았으며 대체로 3요소를 균형시비하는 경우 전분함량이 높은 경향이었고 가리질비료를 다용하거나 인산질비료를 시용하지 않은 경우 낮은 경향이였다. 한편 괴근수량에는 $K_20$O>$P_20_5$>N의 순으로 효과가 높았다. 4. 토성에 있어서는 모래나 자갈이 많이 함유되어 있는 토양에서부터 경직토로 갈수록 전분함량은 낮았으나 10a당 전분수량은 조사토 및 식양토에서 높았다. 5. 저장기간중 전분함량은 수량직후에 가장 높고 저장일수가 경과함에 따라 감소하였으나 수확후 10일에서 급격히 감소되었고 그 후의 감소는 근소하였다.

• 유기물자원화
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• 제4권2호
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• pp.19-25
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• 1996

본 연구는 실험실규모로 제작된 고속퇴비화기를 이용하여 음식물쓰레기를 퇴비화하고자 하였다. 연구의 주된 지표는 수분, 온도, C/N비였다. 수분을 조건으로한 실험에서 pH 변화는 60%가 가장 높았으며, 70%는 혐기성반응이 일어남을 볼 수 있었고 C/N비 변화에서는 $NH_3$의 다량발생으로 질소소실의 우려가 있는 것으로 드러났다. 온도를 조건으로 한 실험에서 $60^{\circ}C$의 pH가 가장 높았으며 $70^{\circ}C$의 pH는 토양의 pH 보다 낮게 나타나 지나친 고온은 퇴비화에 역효과를 나타냄을 볼 수 있었고, C/N비의 실험에서는 C/N비 25가 pH와 C/N비의 변화가 가장 작았다. 결과적으로 음식물쓰레기의 퇴비화에서 수분은 50~60%, 온도는 $60^{\circ}C$, C/N비는 25가 적당함을 알 수 있었으며, 조건을 잘 조절해 준다면 56시간안에 퇴비화가 가능할 것으로 판단된다.