• 한국유기농업학회지
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• 제6권1호
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• pp.151-160
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• 1997

Azospirillum sp., photosynthetic bacteria(Rhodopseudomonas sp.) and Pseudomonas sp. were separated and screened from soil and soilless culture, and identificated. The antifungal activities against root-infected pathogens and plant growth promoting effects of the cultured solution of the starins(5.0$\times$105 cells/$m\ell$) in the peatmoss compost on the early growth of cucumber and tomato seedling were investigated. Azospirillum sp. and Pseudomonas sp. showed a antifungal activities against Fusarium sp., Pythium sp. and Rhizoctonia sp in thed ranges of 51.0% to 72.0% on potato dextrose agar medium, however photosynthetic bacteria had not antifungal activities. When cultured solution of Azospirillum sp., photosynthetic bacterial and Pseudomonas sp. were bacterialized by mixing with peatmoss compost, early growth of cucumber and tomato in terms of plant height, number of leaves, leaf area, root length, fresh anf dry weight of leaf, stem and root were promoted, especially photosynthetic bacteria had a the best plant growth promting activities.

• 아시안잔디학회지
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• 제11권1호
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• pp.59-72
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• 1997

The influence of respiration on photosythetic electron transport were investigated in the Wid type and psaB mutants from Syneehocystis sp. PCC6803. The amount of glucose uptake in the wild type was proportional to the glucose concentration added in wild type and less than that of psaB mutants in the dark. It was suggested that psaB mutants more depend on the glucose than the wild type. It was investigated how the activities of isocitrate dehydrogenase(IDH) and glucose-6-phos-phate dehydrogenase(G6PDH) were changed. The activities of IDH were very low. While, the ac-tivities of G6PDH were much higher than that of IDH. These results agree to the reports that ex-ogenous glucose was dismilated aerobically via Oxidative Pentose Phosphate Pathway in heterotrophic cyanobacteria. PsaB mutants showed high G6PDH activity in the presence of glucose as well as in the dark and high respiratory activities especially in the dark. It was also investigated how photosynthetic electron transport activities were changed. PsaB mutants showed higher photosynthetic electron tranasport activities than wild type in the presence of glucose as well as in the dark. In the results, it was proposed that photosynthetic electron transport between PS I and PS U was complemented by respiratory electron transport through the NADPH generated by Dxidative Pentose Phophate Pathway in psaB mutant from Synechocystis sp. PCC6803. Key words: Photosynthetic electron transport, Respiration, Synechoystis sp. PCC6803, psaB mutant, Glucose uptake, IDH, G6PDH, Respiratory electron transport activity.

• 미생물학회지
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• 제13권1호
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• pp.31-36
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• 1975

Chlorella ellipsoidea cells were cultured in a phosphate, magnesium, sulfur or potassium-free medium. Some portions of cells were taken out at intervals during the culture, and physiological activities such as growth rate, reproduction, photosynthetic activity, and biosynthesis of cholorophyll of macro-element deficient cells were measured. 1) Generally, growth rate, reproduction, photosynthetic activities, and biosynthesis of chlorophyll of the macro-element deficient cells decreased more or less, compared with those of the normal cells. 2) The growth and reproduction of the algal cells in sulfur, or magnesium free medium were retarted severely with the chlorosis ; the photosynthetic activity and the content of chlorophyll showed the same tendency. 3) It is considered that the decrease in growth rate of macro-element deficient Chlorella cells is due to the decrease in photosynthetic activity owing to the decrease in chlorophyll content of the cells.

• The Korean Journal of Ecology
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• 제16권3호
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• pp.353-364
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• 1993

To elucidate ecophysiological factors affecting nutural distribution of evergreen broad-leabed trees in Danohad National Marine Park, water potential, relative water content and photosynthetic activities of 4 species, Cammellia japonica, Machilus thunbergii, Castanopsis cuspidata var.sieboldii and Quercus acuta, were potential began to decrease from 07:00h to its minimum value at 13:00h for C. cuspidata var. sieboldii (-14.3bar) and Q. acuta (-19.4bar) at 16:00 h for M. thunbergii(-17.0bar) and at 19:00 h for C. japonica (-14.5bar), and these showed similar trends to relative water content. Photosynthetic activities of 4 species began to increase from 7:00 h and reached maximum values before their minimum values of water potential occureed. Optimum temperature renges of photosynthetic activities was $18~20^{\circ}C$ for C. japonica - M. thunbergii and $14~16^{\circ}C$ for C. cuspidata var. sieboldii Quercus acuta.Q.acuta had the highest light saturation point of $0.4mM/m^2/s$ and C. japonica the lowest of $0.15mM/m^2/s$. Water potential of 4 species subjected to water stress, began to decrease after 1st day of drought and after 21th day of drought, those of C. japonica, M. thunbergii, C. cuspidata var. sieboldii and Q. acuta decreased to species began to decrease after 7th day of drought and after 21th day, those of M. thunbergii, C. cuspidata var. sieboldii and Q. acuta were dropped to about 50% and C. japonica 83.5%. Photosynthetic activity of 4 specie began to decline in the order of C. cuspidata var. sieboldii, Q.acuta, C. japonica and M. thunbergii after 10th day of drought. These results suggest that the segregated disributions of C. japonica - M. thunbergii on vally positions and C. cuspidata var. sieboldii - Q. acuta on slopes were associated with different responses of water status and photosyntheties to their environment.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.714-718
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• 1998

Various mutants either lacking or having decreased levels of light-harvesting complexes and reaction center complex were obtained with a high frequency by an increased formation of poly-3-hydroxybutyrate (PHB) in Rhodobacter sphaeroides. One of the photosynthesis-defective mutants, PY-17, which was devoid of any of the light-harvesting complexes (B800-850, B875) as well as the reaction center complex, was analyzed further. The mutant showed substantial transcription of the puhA, pufKBALMX, and pucBAC operons coding for the structural proteins of the photosynthetic complexes although each of the activities was lower than that of the wild type. Translation of the pufKBALMX and pucBAC operons were also active in the mutant although with activities different from the corresponding one of the wild type. From these results the mutation appears to exert its effect at the post-translational level of the photosynthetic complex assembly. Complementation of the photosynthesis-defective phenotype of the mutant was achieved with an about 12-kb DNA region containing the puhA gene. The relationship between the formation of PHB and photosynthetic complexes is discussed.

• Journal of Plant Biology
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• 제36권2호
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• pp.133-140
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• 1993

The photosynthetic activities in relation to oxygen evolution rates, quantum yield, CO2 uptake rates and room temperature chlorophyll fluorescence were investigated in cotyledons of cucumber seedlings exposed to low temperature (at 4$^{\circ}C$) for 24 h. Light-chilling caused more inhibition on light-saturated maximum oxygen evolution rates, quantum yield, and CO2 uptake rates than dark-chilling did in the cucumber plant. Light-chilling induced more marked increase in Fo and decrease in (Fv)m/Fm than dark-chilling did in the room temperature chlorophyll induction kinetics. The above results affected by chilling in the light are considered to be associated with the partial damage of the reaction center of PS II and the decreased photosynthetic activities. There occurred a large decrease in qQ with little change in qNP in the light-chilling plant. When light- and dark-chilled plants were recovered at room temperature for 24 h and their chlorophyll fluorescences were induced with light doubling technique, light-chilled plants showed more smaller magnitude and rate of fluorescence relaxation than dark-chilled plants. These suggest that light-chilling might cause some alterations in transthylakoid pH formation, and that photosynthetic apparatus of cucumber cotyledons is more susceptible to light-chilling. In the fast fluorescence induction kinetics, FR was decreased by 60% in the light-chilled plants with reference to $25^{\circ}C$ light-grown plants, while the dark-chilled plants showed a decreased rate of only 20% with reference to $25^{\circ}C$ dark-treated plants for 24 h, indicating that cucumber seedling is very sensitive to chilling stress. So, it is certain that chilling injury to the photosynthetic apparatus is strongly dependent on the presence of light in cucumber seedlings.

• Journal of Ginseng Research
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• 제15권2호
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• pp.139-143
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• 1991

This study investigated the relations between the photosynthetic rate and the activities of antioxidatile enzymes, glutathione reductase, ascorbate free radical reductase, ascorbate peroxidase, glutathione peroxidase, and ascorbate oxidase, in the leaves of Panax ginseng. Under the normal cultivation condition, Panax in showed lower g1utathione reductase and ascorbate free radical reductase activities the Glycine max. But P ginseng showed higher 91utathione Peroxidase, ascorbate Peroxidase, and ascorbate oxidase activities than C. Panax. Therefore, P. ginseng showed weak activities of reductases for the reduction of the oxidized antioxidants. Under the light intensity of 25 KLux, the reductases showed a decrease of over 75% after 24 hours. But the peroyoxidases decreased about 40%. These results showed that the decrease of reductases acitivities was consistent with the decrease of photosynthetic rate. Therefore, we consider that the regulation of antioxidative enzymes or the application of exogenous antioxidants will be effective means for the protection of photodamage in p. ginseng.

• 미생물학회지
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• 제5권1호
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• pp.15-19
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• 1967

Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Physiological activities such as growth rate, reproduction, endogenous and glucose respiration, photosynthetic activity and biosythesis of chlorophyll of the micro-element definition cells were measured. It generally, growth rate, respiratory and photosynthetic activities, and biosynthesis of chlorophyll of the micro-element deficient cells decreased more or less, compared with those of the normal cells. The growth of the algal cells in an iron-free medium were retarded severely with the chlorosis, and the photosynthetic activity of the cells decreased remarkably even though the low content of chlorophyll in the cells owing to the iron-deficiency is considered. Therefore, it is deduced that iron takes part in the photosynthetic process itself, possibly by its participation in the photo phosphorylation coupled with electron transport. Respiratory activity of boron-deficient cells showed the most severe decrease whereas those of the molybdenum-deficient cells showed very slight decrease in spite of severe growth retardation.

• Journal of Plant Biology
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• 제7권3호
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• pp.9-14
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• 1964

The sensitivities of Chlorella ellipsoidea to ${\gamma}$-ray from Cobalt-60 were determined by measuring the photosynthetic and respiratory activities and the changes in phosphate contents in various fractions of the irradited cells, which were further grown in a standard medium after irradiation, were compared to those of non-irradiated normal cells. The photosynthetic and repiratory activities of the cells were almost inversely proportional to the dose of ${\gamma}$-ray irradiated and the photosynthetic activity was more sensitive than the respiratory activity of the cells. The most sensitive to ${\gamma}$-ray was growth activity, followed by photosynthesis, exogenous and endogenous respirations of the cells in decreasing order. Chlorella cells were so resistant to ${\gamma}$-ray comapred with other organisms that about 280,000 r dose of ${\gamma}$-ray irradiaton was necessary to reduce as much as half the subsequent photosynthetic activity. When the irradiated algae were further cultured in a standard medium, the phosphate contents in the fraction of DNA, RNA and phosphoprotein decreased considerably compared with those of non-irradiated normal cells, while the phosphate contents in the fraction of polyphosphates increased than those of control. Therefore, it was deduced that ${\gamma}$-ray inhibited the synthesis of DNA from polyphosphates, that the growth of Chlorella cells were consequently retarded.

• 한국균학회지
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• 제18권4호
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• pp.181-190
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• 1990

The growth and biochemical activities of Chlorella fusca were studied in the presence of different concentrations of either filtrates or mycelial mats of Saprolegnia ferax and Pythium graminicola. Low concentrations of both fungal filtrates exerted increase in total count, dry weight and in the biosynthesis of photosynthetic pigments, carbohydrates and nitrogen content. High concentrations showed inhibitory effect on both growth and biochemical activities of Chlorella fusca. Supplementation with different concentrations of dry mycelial mats of either fungi the culture of Chlorella showed elevation in biomass, dry weight, and biosynthesis of carbohydrates and nitrogen content especially at low concentrations. The contents of photosynthetic pigment were inhibited only at low concentrations. Neither the culture filtrate of Pythium nor Saprolegnia had cellulolytic activity, although polygalacturonase enzymes were detected, whereas chloroform-extract of both fungal filtrates showed blue spots under long wave light (366 nm).