• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.641-646
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• 2003

An accurate and efficient method for measuring the mass of hairy roots using conductometry is established. A conductivity equation expressed in terms of the concentration of the ion species in the medium is suggested. By using this equation, the effect of the individual ions on the total conductivity can be quantitatively analyzed. An equation for the in situ estimation of the cell growth coefficient for determining the mass of hairy roots is established based on measurements of the nitrogen concentration and conductivity during cultivation. The proposed equation does not require preliminary experiments to determine the cell growth coefficient. Instead, the physiological characteristics of the plant species are reflected by introducing the cellular nitrogen content. Since the cell growth coefficient is determined by measuring the major ionic nutrient concentrations, it is more effective to express the dynamics of an actual culture system. This improved method for determining the mass of hairy roots was successfully utilized in a fed-batch culture system.

• ALGAE
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• 제36권4호
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• pp.327-332
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• 2021

Raw material of gelidioid red algae yielding high-quality agar has been in short supply due to overharvesting, but in situ farming of gelidioids has not been practical due to their slow growth. To produce vegetative seedstock of a cosmopolitan species, Pterocladiella capillacea, we investigated the number and length of regenerated branches arising from sectioned fragments during 3 weeks of laboratory culture at 10, 15, 20, and 25℃. All sectioned fragments formed axis-like branches mostly from the upper cut edge and stolon-like branches mostly from the lower cut edge, showing a high capacity of regeneration and intrinsic bipolarity. At 20℃, the number of regenerated branches increased to 2.74 ± 1.29 on the upper cut edge and 4.26 ± 2.66 on the lower cut edge. Our study reveals that the use of fragments bearing regenerated branches as seedstock can be a simple method to initiate fast propagation for mass cultivation in the sea or outdoor tank.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.304-308
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• 2005

The response of IPTG induction was investigated through the monitoring of the alkali consumption rate and buffer capacity during the cultivation of recombinant E. coli BL21 (DE3) harboring the plasmid pRSET-LacZ under the control of lac promoter. The rate of alkali consumption increased along with cell growth, but declined suddenly after approximately 0.2 h of IPTG induction. The buffer capacity also declined after 0.9 h of IPTG induction. The profile of buffer capacity seems to correlate with the level of acetate production. The IPTG response was monitored only when introduced into the mid-exponential phase of bacterial cell growth. The minimum concentration of IPTG for induction, which was found out to be 0.1 mM, can also be monitored on-line and in-situ. Therefore, the on-line monitoring of alkali consumption rate and buffer capacity can be an indicator of the metabolic shift initiated by IPTG supplement, as well as for the physiological state of cell growth.

• Korean Chemical Engineering Research
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• 제52권1호
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• pp.126-132
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• 2014

본 연구에서는 높은 농도의 염류가 집적된 시설재배지 토양의 제염을 위해 전기동력학적(EK) 기술을 적용한 파일럿 규모($2{\times}3{\times}0.2m^3$, $W{\times}L{\times}D$)의 실증시험을 실시하였다. 실험 전 토양의 전기전도도(EC)는 약 9 dS/m였으며, 토양내 주요 염류는 $Ca^{2+}$, $Cl^-$, $SO_4^{2-}$ 이온이었다. 2주간의 EK 처리 후 토양의 EC는 실험 전에 비해서 52% 감소하였으며, 이 중 대부분은 초기 1주일 이내에 제거되었다(47%). 이는 주로 $Na^+$와 $Cl^-$의 제거에 의한 것으로 보이며, 주요 염류 이자 토양에 대해 높은 흡착능을 가지는 $Ca^{2+}$와 $SO_4^{2-}$이온은 상대적으로 제거율이 낮았다. EK 실험이 진행되는 동안 토양의 온도는 전류의 세기에 따라 증가하여 최대 $50^{\circ}C$까지 증가하였다. 따라서 작물이 재배 중인 토양의 원위치 EK 적용을 위해서는 토양의 온도 상승을 제한하기 위해 전류를 조절할 필요가 있다. 결론적으로 EK 기술을 이용하여 경작 중이거나 휴경 중인 시설재배지 토양의 원위치 염류 제거가 가능할 것으로 판단되며 효율적인 탈염을 위해서는 적절한 운전 전략이 요구된다.

• 한국산학기술학회논문지
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• 제22권5호
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• pp.379-386
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• 2021

본 연구 목적은 미세조류 대량생산을 위한 ICT와 BT기술이 융합된 계단식 연속 배양 시스템(CCCS)을 개발함에 있다. 본 시스템은 미세조류 성장에 필요한 주요 운전변수인 pH, 온도, 이산화탄소와 조도 제어를 통해 실시간 배양조건 유지를 통해 세포성장 증진과 계절과 장소에 관계없이 미세조류를 생산할 수 있어 경제성이 확보 된 시스템이다. 또한, 안정적이고 높은 생산성을 제공하는 장점을 갖는다. 본 연구에서는 이 시스템을 활용하여 71일간 미세조류를 배양하고 실험 데이터를 분석하였다. 그 결과, 배양초기 O.D.는 수조1에서 0.006로 측정되었으며 이후 배양 71일, O.D.는 수조1: 0.399, 수조2: 0.961, 수조3: 0.795 그리고 수조4: 0.438로 측정되었다. 따라서 배양기간 동안 연속적인 배양이 가능함이 확인되었다. 대량 배양 방식인 ISMC (In-situ monitoring and control)기반 스마트팜을 제시하고, 본 개발기술을 통해 미세조류 이외의 수경재배 기반의 약용식물 등에 적용하여 식품, 화장품 그리고 의료 소재용 고부가가치 식물 재배에도 적용이 가능한 상업화 적합 기술이라 사료된다.

• Molecules and Cells
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• 제23권3호
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• pp.280-286
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• 2007

L-asparaginase (EC 3.5.1.1) catalyzes the hydrolysis of the amide group of L-asparagine, releasing aspartate and $NH_4{^+}$. We isolated a low temperature-inducible cDNA sequence encoding L-asparaginase from soybean leaves. The full-length L-asparaginase cDNA, designated GmASP1, contains an open reading frame of 1,258 bp coding for a protein of 326 amino acids. Genomic DNA blotting and fluorescence in situ hybridization showed that the soybean genome has two copies of GmASP1. GmASP1 mRNA was induced by low temperature, ABA and NaCl, but not by heat shock or drought stress. E. coli cells expressing recombinant GmASP1 had 3-fold increased L-asparaginase activity. A possible function of L-asparaginase in the early response to low temperature stress is discussed.

• 한국토양비료학회지
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• 제48권2호
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• pp.105-118
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• 2015

This study was carried out to investigate the effects of profile disturbance with different artificial accumulation history on physico-chemical properties of soil under plastic film house. The investigations included soil profile description using soil column cylinder auger F10cm x h110cm, in situ and laboratory measurements of soil properties at five sites each at the cucumber (Site Ic ~ Vc) and grape (Site Ig ~ Vg) plastic film houses with artificial soil accumulation. The sites except sites Ic, IVc, IVg and Vg, belong to ex-paddy area. The types of accumulates around root zone included sandy loam soil for 3 sites, loam soil for 1 site, saprolite for 2 sites, and multi-layer with different accumulates for 3 sites. Especially, Site IIg has mixed plow zone (Ap horizon) with original soil and saprolite, whereas disturbed soil layers of the other sites are composed of only external accumulates. The soil depth disturbed by artificial accumulation ranged from 20 cm, for Site IIg, to whole measured depth of 110 cm, for Site IVc, Vc, and Site IVg. Elapsed time from artificially accumulation to investigation time ranged from 3 months, Site IIc, to more than 20 years, Site Vg, paddy-soil covering over well-drained upland soil during land leveling in 1980s. Disturbed top layer in all sites except Site Vg had no structure, indicating low structural stability. In situ infiltration rate had no correlation with texture or organic matter content, but highest value with highest variability in Site IIIc, the shortest elapsed time since sandy loam soil accumulation. Relatively low infiltration rate was observed in sites accumulated by saprolite with coarse texture, presumably because its low structural stability in the way of weathering process could result in relatively high compaction in agro-machine work or irrigation. In all cucumber sites, there were water-transport limited zone with very low permeable or impermeability within 50 cm under soil surface, but Site IIg, IIIg, and Vg, with relatively weak disturbance or structured soil, were the reverse. We observed the big change in texture and re-increase of organic matter content, available phosphate, and exchangeable cations between disturbed layer and original soil layer. This study, therefore, suggest that the accumulation of coarse material such as saprolite for cultivating cash crop under plastic film house might not improve soil drainage and structural stability, inversely showing weaker disturbance of original soil profile with higher drainage.

• 한국자원식물학회지
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• 제23권4호
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• pp.374-378
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• 2010

식물 수분 특성을 규명하는 것은 재배뿐만 아니라 현지외 보전에도 필수적인 연구이다. 본 연구에서는 희귀식물로 알려진 꼬리진달래의 현지외 보전을 목적으로 P-V 곡선법을 이용하여 수분특성을 조사하였다. 꼬리진달래 잎의 최대팽압시의 삼투포텐셜은 월악산과 석포리의 개체가 각각 -1.5 MPa 이었고, 연하리의 삼투포텐셜이 -1.2 MPa로 다소 높게 나타났으며, 초기원형질분리점의 삼투포텐셜은 월악산 -1.29 MPa, 연하리 -1.02 MPa, 석포리 -1.26 MPa로 연하리의 초기원형질분리점이 다소 높게 나타났다. 꼬리진달래의 세포막의 최대탄성계수($E_{max}$)값은 석포리 14.0 MPa로 나타냈고, 월악산 8.67 MPa로 다소 낮은 값을 나타냈으며, 연하리 4.00 MPa로 석포리에 비해 3배정도 낮은 값으로 나타났다. 초기원형질분리점의 상대함수율은 월악산 83.2%, 연하리 83.1%, 석포리 83.8%으로 비교적 수분보존 기능이 비교적 좋은 수종이다. 따라서, 꼬리진달래는 수분특성상 다른 진달래와 철쭉, 관목류들과 비슷한 경향을 나타냈으며 현지외 이식시 자생지간 내건성이 상대적으로 좋은 월악산, 석포리의 개체가 좋을 것으로 판단된다.

• Plant Biotechnology Reports
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• 제2권3호
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• pp.191-198
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• 2008

Germplasm characterization and evolutionary process in viable populations are important links between the conservation and utilization of plant genetic resources. Here, an investigation is made, based on molecular and biochemical techniques for assessing and exploiting the genetic variability in germplasm characterization of taro, which would be useful in plant breeding and ex situ conservation of taro plant genetic resources. Geographical differentiation and phylogenetic relationships of Indian taro, Colocasia esculenta (L.) Schott, were analyzed by random amplified polymorphic DNA (RAPD) and isozyme of seven enzyme systems with specific reference to the Muktakeshi accession, which has been to be proved resistant to taro leaf blight caused by P. colocasiae. The significant differentiations in Indian taro cultivars were clearly demonstrated by RAPD and isozyme analysis. RAPD markers showed higher values for genetic differentiation among taro cultivars and lower coefficient of variation than those obtained from isozymes. Genetic differentiation was evident in the taro accessions collected from different regions of India. It appears that when taro cultivation was introduced to a new area, only a small fraction of genetic variability in heterogeneous taro populations was transferred, possibly causing random differentiation among locally adapted taro populations. The selected primers will be useful for future genetic analysis and provide taro breeders with a genetic basis for selection of parents for crop improvement. Polymorphic markers identified in the DNA fingerprinting study will be useful for screening a segregating population, which is being generated in our laboratory aimed at developing a taro genetic linkage map.

• 아시안잔디학회지
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• 제18권2호
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• pp.97-104
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• 2004

Putting green의 높은 이산화탄소 함량은 많은 골프장 관리자들에게 있어서 green 관리시 항상 난제로 여겨져 왔다. 무기성 토양은 green 근권(根圈:토양 중에서 뿌리의 영향이 미치는 범위)에서 이용 가능한 자유산소를 제한하며 그로 인하여 뿌리발달을 방해하며 잔디성장을 위한 영양분이 용도를 제지시킨다. 이 실험은 현 운영되는 골프장 (South illinois, Carbondale, U,S,A) 에서 선택 되어진 아홉 개의 green 에서 근권의 $CO_2$ 함유량과 잔디품질 (Turf qualify Index) 사이의 관계성을 조사하기 위하여 실행되어졌다. 아홉개의 putting green에서 각 green 의 다섯 곳의 소구획을 무작위로 선택하여 1998년 8월 부터 1999년 8월 까지 일곱번의 반복으로 잔디품질, $CO_2$ 함유량, 수분함량과 수분 침투율 (Infiltration rate) 을 측정하였다. $CO_2$ 함유량은 이른 봄 보다 늦은 여름에 높았으며 $CO_2$ 함유량이 높아짐에 따라 잔디품질은 급격히 낮아졌다. 수분함량이 많을수록 $CO_2$ 함유량이 높았으며 반대로 수분 침투율은 낮아짐을 보였다. 높은 수분 침투율은 $CO_2$ 함유량을 감소시켰다. 결론적으로 알맞은 토양의 물리적 조건(수분 함량과 침투율)이 $CO_2$ 함유량과 잔디성장에 있어서 매우 중요한 역할을 함을 알 수 있다. 잔디품질의 향상을 위해 putting green root zone의 알맞은 배수와 함께 근권의 공기 조건이 매우 중요함이 이 실험을 통해 조사되었다.