• Journal of Ecology and Environment
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• 제29권3호
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• pp.237-245
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• 2006

강원도 평창군 일대에서 화전 후 묵밭의 식생 천이에 따른 식물량, 순 일차 생산성 및 P/B 비의 변화를 조사하였다. 초본의 지상부 식물량은 5년차 묵밭에서 3.8 ton/ha로 가장 많았다. 낙엽 건중량은 50년차 묵밭까지 증가한 다음 감소하는 포물선형 변화를 나타내었다. 천이가 진행됨에 따라 흉고 단면적은 로그 함수적으로 증가하는 경향을 나타내었다. 교목의 목본 수는 15년차 묵밭까지 빠르게 증가하다가 경과 년 수에 따라 자가 솎음질 과정을 거쳐 감소하는 경향이었다. 80년차 묵밭에서 DBH 등급에 따른 목본의 분포는 역 J 자형을 나타내었고, 우점종은 신갈나무이었다. 식물 현조량은 천이 초기와 후기 단계에서 완만한 증가를 나타내었고, 중기 단계인 $10{\sim}50$년차 묵밭에서 빠르게 증가하였다. 5, 10, 20, 50 및 80년차 묵밭의 식물 현존량은 각각 5, 14, 75, 251 및 373 ton/ha로 추정되었다. 연간 순 생산성은 초기 35년간 점진적인 증가 후 감소하여 점차 안정화하는 경향을 나타내었다. 연간 순 일차 생산성의 증가 속도는 천이 중기 단계 보다 초기 단계에서 빠르게 증가하였다. 5, 10, 20, 35, 50 및 80년차 묵밭의 순 일차 생산성은 각각 8.6, 9.3, 12.9, 15.1, 13.7 및 3.6 ton/ha/yr이었다. P/B 비율은 천이가 진행됨에 따라 지수 함수적으로 감소하는 것으로 추정되었다. 5, 10, 20, 50 및 80년차 묵밭에서 추정된 P/B 비율은 각각 0.60, 0.39, 0.19, 0.06 및 0.01이었다. 이러한 결과는 Odum(1969)이 제시한 삼림천이 과정의 생물 에너지론과 잘 부합하였다.

• Journal of Microbiology and Biotechnology
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• 제22권7호
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• pp.967-974
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• 2012

Cultivation of Spirulina platensis using ammonium salts or wastewater containing ammonium as alternative nitrogen sources is considered as a commercial way to reduce the production cost. In this research, by analyzing the relationship between biomass production and ammonium-N consumption in the fed-batch culture of Spirulina platensis using ammonium bicarbonate as a nitrogen nutrient source, an online adaptive control strategy based on optical density (OD) measurements for controlling ammonium feeding was presented. The ammonium concentration was successfully controlled between the cell growth inhibitory and limiting concentrations using this OD-based feedback feeding method. As a result, the maximum biomass concentration (2.98 g/l), productivity (0.237 g/l d), nitrogen-to-cell conversion factor (7.32 gX/gN), and contents of protein (64.1%) and chlorophyll (13.4mg/g) obtained by using the OD-based feedback feeding method were higher than those using the constant and variable feeding methods. The OD-based feedback feeding method could be recognized as an applicable way to control ammonium feeding and a benefit for Spirulina platensis cultivations.

• 한국해양바이오학회지
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• 제10권1호
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• pp.26-33
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• 2018

Fucoxanthin has been reported as bioactive compounds exhibiting strong antioxidant, anticancer and anti-inflammatory activities. Owing to its a wide range of applications and potentials, commercial production of fucoxanthin from algae has been attracted many attentions. Although, most of seaweeds and diatoms contain fucoxanthin as major carotenoid contents, low productivity of fucoxanthin still hinder the industrial application. Here, we newly isolated and identified indigenous marine diatom Odontella sp. BS-003 as a resource of fucoxanthin production. The characterization, optimization and production of the fucoxanthin, along with other bioactive compound omega-3 fatty acid from odontella sp. BS-003 were analyzed in this study, and the results represented optimal culture condition (two-fold silicate containing F/2 medium) significantly enhanced the algal biomass productivity. The maximum biomass (1.83 g/L), fucoxanthin (3.88 mg/g), along with omega-3 fatty acid (10 %, w/w) were obtained from the 10 L of photobioreactor. Based on the results, it is speculated that the microalga Odontella sp. BS-003 can be a promising natural resource for the production of bioactive compounds.

• 한국해양바이오학회지
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• 제11권1호
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• pp.14-22
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• 2019

Omega-3 fatty acids and carotenoids, which are known as representative high-value substances derived from microalgae, are being studied from various diatoms. Most of the diatoms contain fucoxanthin and omega-3 fatty acid. Fucoxanthin produced by diatom has been reported as bioactive compounds exhibiting strong antioxidant, anticancer and anti-inflammatory activities. However, the low growth rate and fucoxanthin content of diatoms are one of the big obstacles to the industrial application. In this study, indigenous marine diatom Achnanthidium sp. BS-001 was isolated for a candidate of fucoxanthin producer. Light intensity and temperature for the culture of Achnanthidium sp. BS-001 were optimized on PhotoBiobox. Optimization of silicate concentration for increasing BS-001 biomass productivity was confirmed in F/2 medium with various concentration of sodium silicate. As a result, condition of light intensity, temperature, and silicate concentration for optimal cultivation were $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, $18^{\circ}C$ and 0.106 mM, respectively. Maximum biomass productivity reaches to $154.3mg{\cdot}L^{-1}{\cdot}day^{-1}$, and then the content of omega-3 fatty acids and fucoxanthin were $19.4mg{\cdot}g^{-1}$, $9.05mg{\cdot}g^{-1}$, respectively. These results indicate that Achnanthidium sp. BS-001 has the potential to be used as a source of omega-3 fatty acids and fucoxanthin.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권1호
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• pp.73-77
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• 2005

Plant-derived natural products have been and will continue to be valuable sources. Elicitors have been employed to modify cell metabolism in order to enhance the productivity of useful metabolites in plant cell/tissue cultures. In this study, several elicitors were used to improve the productivity of useful metabolites and to reduce culture time for archiving high concentration in P. ginseng hairy root cultures. The addition of chitosan, chitosan oligosaccharide and alginate oligosaccharide to the culture of P. ginseng hairy roots caused growth to be inhibited with the increase in elicitor concentration. The usage of the chitosan elicitor and D-glucosamine caused a slight decrease in hairy root growth, whereas total ginseng saponin accumulated slightly with the increase in elicitor concentration. When gel beads were added to the culture medium at the initial period, hairy root growth was enhanced. The maximum growth was 1.35 times higher than that of the control at $1\%$ (w/v). Total ginseng saponin content decreased due to the addition of alginate beads. This would result in consistent diffusion of lower levels of calcium ions during the culture period that promotes biomass growth.

• 한국산림과학회지
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• 제70권1호
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• pp.91-102
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• 1985

굴참나무림(林)의 밀도(密度) 차이(差異)에 따른 생장(生長) 및 물질생산(物質生産)을 비교분석(比較分析)하여 천연림(天然林)의 무육시업자료(撫育施業資料)를 얻고자 경남산청지역(慶南山淸地域)의 해발(海拔) 900 m (A임분(林分) : 6,600본(本)/ha, $15.84m^2/ha$, $\frac{19}{17-20}$년생(年生))와 800 m (B임분(林分) : 4,300본(本)/ha, $16.65m^2/ha$, $\frac{20}{17-21}$년생(年生))의 위치(位置)에 $20m{\times}20m$ 표본점(標本點)을 각각(各各) 설치(設置)하여 조사(調査)한 바를 다음과 같이 요약(要約)할 수 있었다. 조사구내임목(調査區內林木)을 매목조사(每木調査)하고 경급별(徑級別) 평균목(平均木)을 12본(本)씩 벌채(伐採)하여 $W_S$, $W_B$, $W_L$, $W_{Ba}$ 등(等)의 건중량(乾重量)을 측정(測定), $D^2H$와의 상대생장식(相對生長式)에 의(依)해 현존량(現存量)과 물질생산량(物質生産量)을 추정(推定)하였다. 생산구조면(生産構造面)에서 광합성부위(光合成部位)는 A임분(林分)이 지상(地上) 2.2 m, B임분(林分)이 지상(地上) 1.2 m 높이서 시작(始作)되었고, 최대광합성부위(最大光合成部位)는 A, B 임분(林分)에서 각각(各各) 4.2 m, 6.2 m 높이였으며 엽면적지수(葉面積指數)는 각각(各各) 4.25 ha/ha, 389 ha/ha로 나타났다. 지상부현존량(地上部現存量)은 A, B임분(林分)에서 각각(各各) 49.51 ton/ha, 59.20 ton/ha이고, 순생산량(純生産量)은 각각(各各) 6.75 ton/ha/yr., 8.99ton/ha/yr.로 B임분(林分)이 더 컸었으나, 현존량(現存量)에 대(對)한 순생산량(純生産量)의 구성비(構成比)에 있어서는 A, B임분(林分)이 각각(各各) 17.5%, 16.7%로 A임분(林分)이 더 컸다. 잎의 순동화율(純同化率), 간재생산능률(幹材生産能率) 및 수피생산능률(樹皮生産能率)을 A, B임분별(林分別)로 추정(推定)한바 NAR은 2.75kg/kg/yr., 3.58kg/kg/yr이고, 간재생산능률(幹材生産能率)은 1.46kg/kg/yr., 2.09kg/kg/yr로 B임분(林分)이 크게 나타나 효과적(効果的)인 공간이용(空間利用)을 하고 있음을 시사(示唆)하고 있으나, 수피생산능률(樹皮生産能率)은 0.60kg/kg/yr., 0.34kg/kg/yr.로 A임분(林分)이 크게 추정(推定)되었다. 이상(以上)의 결과(結果)로서 임분(林分)의 밀도조절(密度調節)을 통(通)하여 생산성(生産性)을 높일 수 있는 굴참나무천연림무육시업(天然林撫育施業)의 자료(資料)와 생산물(生産物) 목표(目標)에 따른 경영(經營)의 지침(指針)을 얻을 수 있을 것으로 생각된다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.209-209
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• 2017

The application of liquid swine manure to soil has been commonly reported to increase crop productivity by improving plant nutrient availability. This study was conducted to investigate the effect of liquid swine manure (LSM) application on yield of green manure crops in paddy. Three different application rates of LSM equivalent to 25%, 50%, and 75% of standard fertilization rate of P were applied to the paddy field after rice harvest, and two cover crops, hairy vetch (Vicia villosa Roth) and barley (Hordeum vulgare L.), were subsequently mix-seeded and cultivated. Plant height of barley was 7% higher in LSM P25% and LSM P50% compared to control treatment (no LSM application), while no significant difference was observed between LSM P75% and control. However, there were no significant differences in plant height of hairy vetch among treatments. Dry matter (DM) yield of green manure increased with LSM application rate, reaching a maximum at LSM P50% (38 and 17% yield increase over control for hairy vetch and barley, respectively), but it decreased at LSM P75% rate. Nitrogen production by green manure crops was the highest in LSM P50% treatment, where the amount of produced N was 57% higher than the optimum N fertilization level for rice ($90kg\;N\;ha^{-1}$). Excess green manure biomass above an optimum level can be removed and utilized either for incorporation into nearby cropland or for sale as fresh forage. Therefore, it is concluded that the application rate of LSM P50% is recommendable for the maximum biomass and nitrogen production from green manure crops in paddy.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.435-440
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• 2001

The purpose of this study was to evaluate mesh size and water velocity for the growth of filamentous periphytic algae(FPA). The growth experiment was carried out in the constructed pilot waterway system with nutrient-rich treated wastewater. Growth rate of FPA was highest at water velocity about 10 cm/s. The maximum standing crop of FPA was $253\;{\mu}g\;chl.a/cm^{3}$, and an average of the net productivity was $3.92\;mgDW/cm^{2}/day\;or\;25.3\;{\mu}g\;chl.a/cm^{2}/day$. Biomass development and growth rates of FPA were highest at the net with 20mm mesh size during the fall season and 10mm mesh size during the winter season.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.114.2-114.2
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• 2011

Furfural is a versatile derivative. It can be utilized for a building-block of furfuryl alcohol production and a component of fuels or liquid alkanes. But in bio-process, furfural is a critical compound because it inhibits cell growth and metabolism. Furfural could be converted from xylose and usually produced from biomass in which hemicellulose is abundant. In this study, furfural production from miscanthus was performed and utilization of miscanthus residue was consequently conducted. At first, hydrolysis for investigation of miscanthus composition and furfural production was performed using sulfuric acid. Previously, we optimized dilute acid pretreatment condition for miscanthus pretreatment and the condition was found to be about 15 min of reaction time, 1.5% of acid concentration and about $140^{\circ}C$ of temperature and 60% (about 7 g/L) of xylose was solubilized from miscanthus. Using the xylose, furfural production was conducted as second step. Approximately $160{\sim}200^{\circ}C$ of temperature was accompanied with the hydrolysis for pyrolysis of biomass. When the investigated condition; $180^{\circ}C$ of temperature, 20 min of reaction time and 2% of acid concentration was operated for furfural production, furfural productivity was reached to be 77% of theoretical maximum. After reaction, residue of miscanthus was utilized as feedstock of ethanol fermentation. Residue was well washed using water and saccharified using hydrolysis enzymes. Hydrolysate (glucose) from saccharification was utilized for the carbon source of Saccharomyces cervisiae K35.

• Journal of Microbiology and Biotechnology
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• 제21권4호
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• pp.430-437
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• 2011

The effects of the agitation and aeration rates on the production of serratiopeptidase (SRP) in a 5-L fermentor (working volume 2-l) were systematically investigated using Serratia marcescens NRRL B-23112. The dissolved oxygen concentration, pH, biomass, SRP yield, and maltose utilization were all continuously measured during the course of the fermentation runs. The efficiencies of the aeration and agitation were evaluated based on the volumetric mass transfer coefficient ($K_La$). The maximum SRP production of 11,580 EU/ml with a specific SRP productivity of 78.8 EU/g/h was obtained with an agitation of 400 rpm and aeration of 0.075 vvm, which was 58% higher than the shake-flask level. The $K_La$ for the fermentation system supporting the maximum production (400 rpm, 0.075 vvm) was 11.3 $h^{-1}$. Under these fermentor optimized conditions, kinetic modeling was performed to understand the detailed course of the fermentation process. The resulting logistic and Luedeking-Piret models provided an effective description of the SRP fermentation, where the correlation coefficients for cell growth, SRP formation, and substrate consumption were 0.99, 0.94, and 0.84, respectively, revealing a good agreement between the model-predicted and experimental results. The kinetic analysis of the batch fermentation process for the production of SRP demonstrated the SRP production to be mixed growth associated.