• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6773-6779
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• 2014

Background: Nanotechnology opens new applications in many fields including medicine. Among all metallic nanoparticles, silver nanoparticles (silver NPS) have proved to be the most effective against a large variety of organisms including toxic cyanobacteria. Materials and Methods: Silver NPs were biosynthesized in vivo with different alga species namely, Spirulina piatensis, Chlorella vulgaris and Scenedesmus oh/iquus following two scenarios. First: by suspending a thoroughly washed algae biomass in 1 mM aqueous $AgN0_3$ solution. Second: by culturing them individually in culture media containing the same concentration of $AgN0_3$. Silver NPs were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive analysis (EDX) and Fourier transform infra-red (FfIR) spectroscopy. The biosynthesized silver NPs were tested for cytotoxic activity against a cancer promoter cyanobacteruim Microcystis aeruginosa, considering effects on cell viability and chlorophyll content. Results: The surface plasmon band indicated the biosynthesis of silver NPs at ~400 nm. Transmission electron microscopy (TEM) revealed that the silver NPs had a mean average size below 100 nm. Energy-dispersive analysis X-ray (EDX) spectra confirmed the presence of silver element. FfIR spectral analyses suggested that proteins and or polysaccharides may be responsible for the biosynthesis of silver NPs and (-COO-) of carboxylate ions is responsible for stabilizing them. The toxic potentialities ofthe biosynthesized silver NPs against the cancer promoter cyanobacterium, Microcystis aeruginosa showed high reduction in viable cells count and the total chlorophyll content. Conclusions: The potential activity of the biosynthesized silver NPs from the studied algae species against Microcystis aernginosa cells is expected to be mainly mediated by the release of silver ions (Ag+) from the particle surface and bioactive compounds as indicated by FfIR analysis.

• 한국환경과학회지
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• 제1권1호
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• pp.1.1-11
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• 1992

To find heavy metal-specific effects on the photosynthetic apparatus of higher plants, we investigated effects of $CuCl_2$, HgCl_2$ and $ZnCl_2$ on electron transport activity and chlorophyll fluorescence induction kinetics of chloroplasts isolated from barley seedlings. Effects on some related processes such as germination, growth and photosynthetic pigments of the test plants were also studied. Germination and growth rate were inhibited in a concentration-dependent manner by these metals. Mercury was shown to be the most potent inhibitor of germination, growth and biosynthesis of photosynthetic pigments of barley plants. In the inhibition of electron transport activity, quantum yield of PS II, and chlorophyll fluorescence induction kinetics of chloroplasts isolated from barley seedlings, mercury chloride showed more pronounced effects than other two metals. Contrary to the effects of other two metals, mercury chloride increased variable fluorescence significantly and abolished qE in the fluorescence induction kinetics from broken chloroplasts of barley seedlings. This increase in variable fluorescence is due to the inhibition of the electron transport chain after PS ll and the following dark reactions. The inhibition of qE could be attributed to the interruption of pH formation and do-epoxidation of violaxathin to zeaxanthin in thylakoids by mercury. This unique effect of mercury on chlorophyll fluorescence induction pattern could be used as a good indicator for testing the presence and/or the concentration of mercury in the samples contaminated with heavy metals.

• 기술사
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• 제18권2호
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• pp.16-22
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• 1985

This study was carried out to evaluate the quality of soybean sprouts grown under three different sources of light. The soybean was germinated under light through blue (251 ux), red (751 ux) and white (50 to 200 lux) polyethylene films at 25$^{\circ}C$ for 10hr./day. Vitamin C, chlorophyll, cellulose and total protein contents were determined and texture was evaluated by tasting soybean sprouts soup. protein pattern in the soybean sprouts were investigated using polyacrylamide gel electrophoresis. Vitamin C, chlorophyll and cellulose contents were increased by white light intensity. The texture of the sprouts grown under white light (50 lux, 100 lux) was better than darkness, but fought under 200 lux. Vitamin C contents of soybean sprouts grown under various sources of light (in order of light : blue > white > red) were higher than theses of ones grown in the darkness. Biosynthesis of chlorophyll was not correlated to Vitamin C content. Total protein contents of cotyledon was not changed significantly under light irradiation. But the soybean sprouts grown under different quality of light, hypocotyl was higher than those grown darkness. (37% and 20% higher for blue light and white light) Densitometric tracing of disc polyacrylamide gel electrophoretic patterns showed that protein of hypocotyl under white light had more high molecular weight protein.

• 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.

• 한국산림과학회지
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• 제100권4호
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• pp.733-737
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• 2011

실외 인위적 온난화 처리가 2년생 굴참나무(Quercus variabilis) 묘목의 엽록소 함량 및 순광합성률에 미치는 영향을 연구하였다. 4개씩의 $1m{\times}1m$ 크기 처리구와 대조구에 굴참나무 묘목 64본을 식재하고, 적외선등을 이용하여 처리구의 대기온도를 대조구보다 $3^{\circ}C$ 높였다. 엽록소 함량 및 순광합성률을 2011년 5월, 7월, 8월, 9월, 10월에 각각 측정하였는데, 5월, 9월, 10월에는 처리구에서 대조구보다 높은 경향을 보였으며, 7월과 8월에는 처리구와 대조구 간에 차이가 없었다. 5월에는 처리구에서 일찍 발달한 잎의 엽록소 함량이 높아 순광합성률이 증가된 것으로 보이며, 7월과 8월에는 엽록소 함량의 포화로 인해 순광합성률이 대조구와 유의적인 차이를 나타내지 않은 것으로 보인다. 그러나 9월과 10월은 온난화 처리에 의해 엽록소 합성이 촉진되고 이로 인하여 순광합성률이 증가된 것으로 판단된다.

• 한국미생물·생명공학회지
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• 제35권4호
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• pp.292-297
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• 2007

H. pluviails는 고광도와 질소 결핍 배지 조건에서 ketocarotenoid의 일종인 astaxanthin을 다량 축적하는 녹조류이다. 스트레스가 없는 조건에서 키운 green cell과 astaxanthin이 합성된 red cell을 HPLC를 통해 비교해 본 결과 각 색소의 양이 변화하는 것을 볼 수 있었다. 여러 ester 형태의 astaxanthin이 생합성 되고, zeaxanthin이 늘어난 반면, lutein과 ${\beta}$-carotene은 감소하였다. 또한 total chlorophyll 양이 줄어드는 대신 total carotenoid의 양이 늘어남을 보였다. H. pluvilalis에서 찾아낸 astaxanthin 생합성 경로에 있는 carotenoid hydroxylase, phytoene desaturase, isopentenyl pyrophosphate isomerase, ${\beta}$-carotene ketolase 유전자는 음성대조군인 chloroplast chlorophyll a-b binding protein와는 달리cell이 성장하기 좋은 조건의 상태보다 astaxanthin을 생합성하기 위해 고광도의 스트레스를 받았을 때 더 높은 발현양상을 보이는 것을 확인할 수 있었다.

• Plant Biotechnology Reports
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• 제4권4호
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• pp.269-280
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• 2010

Lilium ${\times}$ formolongi was genetically engineered by Agrobacterium-mediated transformation with the plasmid pCrtZW-N8idi-crtEBIY, which contains seven enzyme genes under the regulation of the CaMV 35S promoter. In the transformants, ketocarotenoids were detected in both calli and leaves, which showed a strong orange color. In transgenic calli, the total amount of carotenoids [133.3 ${\mu}g/g$ fresh weight (FW)] was 26.1-fold higher than in wild-type calli. The chlorophyll content and photosynthetic efficiency in transgenic orange plantlets were significantly lowered; however, after several months of subculture, they had turned into plantlets with green leaves that showed significant increases in chlorophyll and photosynthetic efficiency. The total carotenoid contents in leaves of transgenic orange and green plantlets were quantified at 102.9 and 135.2 ${\mu}g/g$ FW, respectively, corresponding to 5.6- and 7.4-fold increases over the levels in the wild-type. Ketocarotenoids such as echinenone, canthaxanthin, 3'-hydroxyechinenone, 3-hydroxyechinenone, and astaxanthin were detected in both transgenic calli and orange leaves. A significant change in the type and composition of ketocarotenoids was observed during the transition from orange transgenic plantlets to green plantlets. Although 3'-hydroxyechinenone, 3-hydroxyechinenone, astaxanthin, and adonirubin were absent, and echinenone and canthaxanthin were present at lower levels, interestingly, the upregulation of carotenoid biosynthesis led to an increase in the total carotenoid concentration (+31.4%) in leaves of the transgenic green plantlets.

• 미생물학회지
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• 제20권1호
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• pp.27-40
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• 1982

The effects of heavy metals on the growth rate and phosphate metabolism of Chlorella elliposidea cells were investigated. Chlorella cells were cultured in the media treated with Hg(0.3, 0.7, 0.9 ppm), Cd(1, 5, 15ppm), and Zn(1, 5, 50ppm) for 6days. Aliquots cells were taken out at the inoculation and at intervals during the culture, and measured packed cell vlolume and optical density. The inhibitions of heavy metals on the growth rate and chlorophyll contents were traced. Also after 6 days culture, the amounts of inorganic phosphate and organic compounds of various fractions in Chlorella cells were observed. The turbid effects of heavy metals on the growth rate and chlorphyll contents of Chlorella cells were in order of Hg>Cd>Zn. Because heavy metals depressed the biosynthesis of inorganic polyphosphates and nucleic acids and turn over of inorganic phosphates, the amounts of various phosphate compounds were decreased. The inhibitory effect of photosynthesis by heavy metals resulted in lower contents of carbohydrate. Due to the turbidity of biosynthesis of amino acids by heavy metals, contents of protein were reduced in comparison with those of control. It is suggested conciusively that the minimum concentrations affected by heavy metals on the growth rate and phosphate metabolism of Chlorella cells were 0.7 ppm Hg, 15ppm Cd, 50ppm Zn.

• 한국잡초학회지
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• 제14권2호
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• pp.81-93
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• 1994

새로 합성된 KC6361 유도체는 기존 디페닐에테르계 화합물에서 보였던 증상(회백색)과는 달리 식물체의 백화를 유기시킨다. 따라서 이들 화합물의 구조상 특징이 무엇이며 식물체에서 어떠한 작용기작을 갖는지를 알기 위하여 본 실험을 수행하였다. 1) 백화를 유기시키기에 비교적 적당한 구조는 B환의 para 위치에 nitro기가 있고 A환의 meta 위치에 탄소수가 3개 이하의 alkyl 또는 allyl기를 가지는 carbamoyl이 치환되는 것이었다. 벼 등은 2kg/ha 수준에서 미미한 약해를 보여 비교적 좋은 선태성을 가졌고 바랭이, 피, 참방동산이, 비름 등은 0.25~0.5kg/ha에서 기타는 0.5~1.0kg/ha에서 거의 방제되었다. 2) 암조건에서 KC6361은 carotenoid 생성을 억제시켰으나 엽록소는 오히려 촉진시켰다. 명조건의 경우 높은 광도에서는 낮은 광도에서 보다, 엽록소보다는 carotenoid가 더욱 저해되었고 $^{4}C$-acetate의 지방성분으로의 혼입 저해정도는 미약하였다. 3) 단은방주의 생장에 미치는 영향이 norflurazon과 동일한 양상을 보였고, KC6361이 처리된 오이, 식용피에 있어서 carotenoid 성분변화를 볼 때 phytoene 및 phytofluene 함량은 증가된 반면 그 이후의 ${\beta}$-carotene은 감소되어 norflurazon과 같은 경향이었다. 따라서 이상의 결과를 종합하여 볼 때 KC6361의 작용점은 norflurazon과 같이 phytoene or/and phytofluene dehydrogenase를 저해하는 것으로 판단된다.

• 한국잡초학회지
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• 제17권3호
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• pp.314-324
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• 1997

우리나라에서 자생하고 있는 실새삼에는 광합성색소 생합성과정이 존재하는지, 있다면 다른 식물에 비하여 어떠한 특징을 가지고 있는지를 알아보고 광합성색소 대사과정에 작용점을 가지는 제초제에 대하여 반응을 나타내는지를 확인하고자 실험하였다. 1. 야외의 자연광 조건에서 자라고 있는 실새삼 생육지의 엽록소함량은 메꽃 줄기와 비교하여 볼 때 9배가 낮았고, 메꽃 잎과 비교하여 볼 때는 약 50배 낮은 경향이었다. 2. 종자로부터 발아된 실새삼 유묘의 경우 선단부위가 색소함량이 가장 높았다. 생육지의 경우는 신장지(extension stem)에서 색소함량이 가장 높았고, 권지(twining stem), 선단 15cm 아래의 절간 순으로 엽록소와 카로티노이드 함량이 낮은 경향이었다. 그리고 생장이 계속됨에 따라 오래된 줄기에서의 엽록체 퇴화가 신속하게 일어나는 경향이었다. 3. 생육지의 색소함량은 광도에 따라 생체중 1g당 엽록소 함량이 20-170${\mu}g$까지, 카로티노이드 함량은 40-120${\mu}g$ 범위까지 변하는 경향이었다. 자연일장조건에서 채취하여 낮은 색소함량을 가진 줄기를 여러 광도에 24시간 둘 경우 91${\mu}Em^{-2}s^{-1}$PAR 내외의 광도까지는 초기색소함량의 3배까지 증가되었고, 광도가 456${\mu}Em^{-2}s^{-1}$PAR 이상에서는 엽록소 함량의 변화가 거의 없었다. 4, 5mM의 ALA를 외부에서 공급할 경우 메꽃의 근경으로부터 나온 신초에서는 Pchlide가 7배 이상 증가되었으나 실새삼 생육지 선단에서는 40% 정도만 증가되었다. 한편 ALA를 공급한 후 저광도에 둘 경우 미미한 엽록소 증가경향만 보여 상대적으로 실새삼은 ALA에 대해 매우 둔감한 특정을 보였다. 5. Paraquat, norflurazon, oxyfluorfen, diuron 등의 제초제를 처리할 경우 모든 처리에서 색소소실이 관찰되었다. 아울러 oxyfluorfen을 처리하면 일반식물에서와 같이 protoporphyrin IX의 축적도 얼어났다. 이상의 결과로 볼 때 실새삼은 낮은 수준이지만 엽록소 및 카로티노이드 생합성과정이 정상적으로 작동되나 조직부위별로 그 수준이 다르고 주변환경의 영향 특히 광도에 따라 크게 조절되고 성장함에 따라 하부조직에서의 엽록체 퇴화가 빠른 특징을 보였다. 색소대사 과정에 작용점을 가지는 제초제들에 대하여 제초반응은 나타내지만 낮은 수준의 광합성색소 생합성 능력과 기주식물로부터의 영양분 탈취라는 특성을 고려하여 볼 때 탁월한 제초효과를 보여주지는 못할 것으로 생각되었다.