• KSBB Journal
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• v.6 no.2
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• pp.181-187
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• 1991

Physiological and morphological characteristics of Anabaena azollae cells immobilized in a synthetic polymer, polyvinyl(PV), were investigated. The cell density of the non-immersed PV foam reached 4.4mg Chl/g dry wt. PV foam. This is 8 times higher than that of PV-immobiliz action in immersed batch system. And MSX-induced ammonia productivity and the photosynthectic oxygen evolution activity are higher than that of free cells after short-term dark storage. Nitrogenase activity and thermostability of photosynthetic activity are also higher than that of free Anabaena cells after immobilization. Total hydrogen production reached to 1.6ml $H_2$ per reactor (total 4mg Chl) after 6 days.

• Journal of Bio-Environment Control
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• v.8 no.2
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• pp.115-124
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• 1999

This study was conducted to determine the optimum root zone environment condition and proper nutrient management system for lettuce in hydroponics. For the root zone environment condition, several level of pH and electrical conductivity (EC) were treated respectively. Though all the level of pH 4 to pH 8, except pH 3, performed better growth without any visible physiological disorder, the optimum pH of the nutrient solution for lettuce production was pH 5.5 to 6.0. The optimum ionic strength of the solution was EC 1.2 to 1.6 mS $cm^{-1}$ / because higher nutrient level caused tip burn symptom by calcium deficiency. Considering the above results, it is concluded that lettuce can be efficiently mass-produced through the optimum root zone environment.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.209-216
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• 2004

This study was aimed to assess the effects of microclimate factors on lettuce chlorophyll fluorescent responses and to develop an environment control system for plant growth by adopting a simple genetic algorithm. The photosynthetic responses measurements were repeated by changing one factor among six climatic factors at a time. The maximum Fv'/Fm' resulted when the ambient temperature was $21^{\circ}C,\;CO_2$ concentration range of 1,200 to 1,400 ppm, relative humidity of $68\%$, air current speed of $1.4m{\cdot}s^{-1}$, and the temperature of nutrient solution of $20^{\circ}C$. In PPF greater than $140{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, Fv'/Fm' values were decreased. To estimate the effects of combined microclimate factors on plant growth, a photosynthesis efficiency model was developed using principle component analysis for six microclimate factors. Predicted Fv'/Fm' values showed a good agreement to measured ones with an average error of $2.5\%$. In this study, a simple genetic algorithm was applied to the photosynthesis efficiency model for optimal environmental condition for lettuce growth. Air emperature of $22^{\circ}C$, root zone temperature of $19^{\circ}C,\;CO_2$ concentration of 1,400 ppm, air current speed of $1.0m{\cdot}s^{-1}$, PPF of $430{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and relative humidity of $65\%$ were obtained. It is feasible to control plant environment optimally in response to microclimate changes by using photosynthesis efficiency model combined with genetic algorithm.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.249-254
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• 1999

The effects of various levels of Al concentration on growth, nutrient status and net photosynthetic rate of 2-year-old Pinus densiflora Sieb. et Zucc. seedlings grown in a nutrient culture solution were investigated. Al concentrations were added as aluminum chloride($AlCl_3$) at 0(control), 10, 30 and 60ppm to the nutrient culture solution. The nutrient culture solution was maintained at pH 4.0 by adding HCl or NaOH solution. The seedlings were transplanted into the nutrient culture solution and grown in a greenhouse for 90 days from May 8 to August 6, 1996. The treatment above 10ppm of Al concentrations induced a significant reduction on the dry weight growth of the seedlings. The relative growth rate(RGR), net assimilation rate(NAR) and net photosynthetic rate of the seedlings were reduced with increasing of Al concentrations in the nutrient culture solutions. This result suggests that reductions in the RGR and NAR of the seedlings were mainly due to the inhibition of net photosynthesis. In addition, the increase of Al concentrations in a nutrient culture solution decreased the concentration of essential mineral elements such as Ca and Mg in the needle of the seedlings. However, the concentrations of Al of each plant organ increased in the treatment above 10ppm of Al concentrations in the nutrient culture solutions. This result suggests that the increased Al concentration in the belowground part resulted from the decreased concentration of essential mineral elements in the aboveground part of the seedlings.

• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.170-175
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• 2008

To verify suitability of the developed nutrient solution for fertigation culture of cucumber, chemical changes of soil, growth characteristics and yield of cucumber as affected by conventional fertigation method (Control), the developed nutrient solution for fertigation culture (DNF) and Yamasaki cucumber recipe (YCR) were investigated. At 48 days after transplant, photosynthetic and transpiration rate of cucumber leaves were the highest in 3/2 strength of DNF and 1/2 strength of YCR, but not different with the Control, in the later growing period photosynthetic rate was the highest in 3/2 strength of DNF and YCR and was clearly different with the Control, transpiration rate was the highest in 3/2 strength of DNF and 1/2, 1 strengths of YCR. The growth and yield of cucumber, nutrient elements of cucumber leaves except for calcium were more in DNF and YCR than in the Control. Compared with pre-treated loam soil, pH of the soil was low and electric conductivity was high in all treatments, amounts of accumulated phosphorus, potassium, calcium, and magnesium were much in the higher concentrations per the kinds of nutrient solutions. From the above results, it was considered that the developed nutrient solution has suitability as nutrient solution for fertigation culture of cucumber.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.212-217
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• 2011

A photoautotrophic micropropagation methodology in liquid culture medium has a number of advantages for large-scale propagation of plants. This paper describes an improved system for the mass propagation via somatic embryogenesis of the medicinal plant Kalopanax septemlobus Nakai. Somatic embryo-derived young plantlets of K. septemlobus were cultured either under heterotrophic conditions with sucrose on half-strength MS medium with $30gL^{-1}$ sucrose, under heterotrophic conditions without sucrose, or under photoautotrophic conditions (MS liquid medium without sucrose under forced aeration) for four weeks before transferring the plantlets for acclimatization. Plantlets grown under photoautotrophic conditions had more leaves, higher chlorophyll content, a higher net photosynthetic rate (NPR), and a higher survival rate. The results indicate that the photoautotrophic conditions with a forced ventilation system are effective in enhancing the growth of plantlets and the rate of net photosynthesis. The plantlets grown under photoautotrophic conditions had a high survival rate (92%) upon ex vitro transplantation. Our study shows that autotrophically produced plantlets acclimatize better and sooner upon ex vitro transplantation than conventionally cultured plants.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.164-170
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• 2000

This study was carried out to investigate the effect of photosynthetic bacteria to chlorella or ${\omega}-yeast$ on Browth of the rotifer and its dietary value for flounder, Paralicbthys oliraceus. The rotifer fed the chlorella (200,000 cells/ind./day) with the addition of 20 times the photosynthetic bacteria of the chlorella concentration showed the highest growth. But the specific growth rate of 100,000 chlorella/ind./day with the addition of 30 times the photosynthetic bacteria was the most economical feeding regime for mass culture of the rotifer. The rotifer frd ${\omega}-yeast$ with 200,000 cells/ind./days with the addition of 20 times the photosynthetic bacteria of the chlorella conecentration showed the highest growth. Growth and survial rate of the larvae of Paralichithys oiivaceus fed the rotifer reared on both chlorella and ${\omega}-yeast$ with the addition of photosynthetic bacteria were higher than those without the bacteria, and the chlorella had better dietary value than the ${\omega}-yeast$ for the larvae. The larvae fed the rotifer which was cultured with the chlorella of 200,000 cells/ind./day and the photosynthetic bacteria of $4{\times}10^6$ cells/ind./day showed the highest survial rate and growth. The larvae reared with the addition of the photosynthetic bacteris had higher total lipid and the total content of EPA and DHA than those reared without the bacteria. The larvae fed the enriched artemia nauplius with the photosynthetic bacteria also showed higher suurval rate and growth than those fed the nauplius without the enrichment. The optimum enrichment concentration of the photosynthetic bacteria for artemia nauplius was $2{\times}1^7\;cells/ml$. The addition of the photosynthetic bacteria to the chlorella and the ${\omega}-yeast$ was effective to growth of the rotifer and dietary value for the flounder larvae. However, an excessive addition of the bacteria decreased both the growth of the rotifer and the dietary of the larvae.

• Microbiology and Biotechnology Letters
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• v.10 no.1
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• pp.27-32
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• 1982

Many microorganisms capable of hydrogen photoproduction were isolated from samples of mud fiats of paddy field collected in Seongnam area near Seoul. Among the 63 isolants, a strain K-13 was selected for the capability of hydrogen evolution. As the results of examinations in physiological, morphological and cultural characteristics, the strain K-13 was identified as Rhodopseudomonas gelatinosa.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.258-265
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• 2004

The experiment was conducted to investigate the effect of EC and pH of nutrient solution on the growth and quality of the single-stemmed rose grown in a rose factory installed with hydroponic system. The growth and quality of the single-stemmed rose were not significantly different from each other with the EC of the nutrient solutions $1.0\~3.5dS{\cdot}m^{-1}$, which resulted in concluding high concentration of the nutrient solution was not necessary. The optimum range of the EC for single-stemmed rose was $1.5\~2.0dS{\cdot}m^{-1}$ considering plant growth, photosynthetic and transpiration rates. The optimum range of the pH for good plant growth without any visible physiological disorder was $4.0\~6.0$. Therefore, to keep the pH of the nutrient solution for rose low compared to other plants was beneficial for plant growth and uptake of the mineral ions.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.233-235
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• 2003

한국 서해안과 남해안 47개소의 해수와 mud 시료로부터 광합성세균으로 유추되는 13개의 균주를 분리하였고, agar-shake tube method와 RAPD-PCR을 이용하여 4개 서로 다른 균주를 순수분리 하였다. 4개의 균주 중 폐수분해능이 가장 뛰어난 균을 선정하여, 형태학적, 배양적, 생화학적 특성 및 16S rRNA sequencing에 의한 동정결과 purple, sulfur bacteria 쪽에 가까웠으나 형태학적, 배양학적, 생화학적 특성이 purple, non-sulfur bacteria의 Rhodobacter 속에 가장 근접하여, Rhodobacter sp. EGH-24로 명명하였다.