Ultrastructure of Differently Pigmented Synechococcus Cells

1981 ◽  
Vol 36 (9-10) ◽  
pp. 907-909
Author(s):  
Günter Döhler ◽  
Ralf Barckhausen ◽  
Manfred Ruppel
Keyword(s):  
White Light ◽  
Red Light ◽  
Culture Conditions ◽  
Anacystis Nidulans ◽  
Light Conditions ◽  
Pigment Composition ◽  
Pigment Ratios ◽  
Polyhedral Bodies ◽  
Storage Carbohydrates

Abstract Synechococcus (Anacystis nidulans, strain L 1402-1) were grown at + 37 °C in an atmosphere of 0.04 vol.% CO2 using different light conditions. Changing the culture conditions caused alterations in pigment ratios and ultrastructure of Synechococcus. In comparison to the low white and red light grown cells under strong white light the number of thylakoids decreased and an accumulation of storage carbohydrates could be observed. The number of the polyhedral bodies also varied with culture conditions. The results are discussed with reference to the pigment composition and the function of the polyhedral bodies.

Presence of Both Hemidiscoidal and Hemiellipsoidal Phycobilisomes in a Phormidium Species (Cyanobacteria)

1993 ◽  
Vol 48 (1-2) ◽  
pp. 28-34 ◽  
Author(s):  
Martin Westermann ◽  
Wolfgang Reuter ◽  
Christine Schimek ◽  
Werner Wehrmeyer
Keyword(s):  
White Light ◽  
Red Light ◽  
Green Light ◽  
Pigment Ratios ◽  
Light Cells ◽  
Sedimentation Value ◽  
In Cells

Hemidiscoidal and hemiellipsoidal phycobilisomes have been determined in cells of the complementary chromatically adapting cyanobacterium Phormidium sp. C86 . They could be isolated from red and green light-adapted cells, respectively. Hemidiscoidal red light phycobilisomes show molar pigment ratios of allophycocyanin: phycocyanin of 1:4.5 with phycoerythrin lacking. Hemiellipsoidal phycobilisomes induced by green light present allophycocyanin: phycocyanin: phycoerythrin ratios of 1:1:6.8. The differences between the two phycobilisome types could additionally be demonstrated by their ultrastructure and sedimentation values. Isolated red light phycobilisomes have six rods, show dimensions of 70×30×15nm and a sedimentation value of 66 S whereas green light phycobilisomes are nearly twice larger. They contain ten rods and present dimensions of 70×40×25nm and a sedimentation value of 98 S. The number of phycobilisomes in red light cells is almost twice as large as in green light cells. There is evidence that cells grown under white light contain both types as well as “intermediate” forms.

scholarly journals Far-Red Light Acclimation for Improved Mass Cultivation of Cyanobacteria

Metabolites ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 170 ◽  
Author(s):  
Alla Silkina ◽  
Bethan Kultschar ◽  
Carole A. Llewellyn
Keyword(s):  
Biomass Production ◽  
White Light ◽  
Light Emitting Diode ◽  
Red Light ◽  
Industrial Biotechnology ◽  
Light Conditions ◽  
Light Emitting ◽  
Mass Cultivation ◽  
Chlorogloeopsis Fritschii ◽  
Bioactive Product

Improving mass cultivation of cyanobacteria is a goal for industrial biotechnology. In this study, the mass cultivation of the thermophilic cyanobacterium Chlorogloeopsis fritschii was assessed for biomass production under light-emitting diode white light (LEDWL), far-red light (FRL), and combined white light and far-red light (WLFRL) adaptation. The induction of chl f was confirmed at 24 h after the transfer of culture from LEDWL to FRL. Using combined light (WLFRL), chl f, a, and d, maintained the same level of concentration in comparison to FRL conditions. However, phycocyanin and xanthophylls (echinone, caloxanthin, myxoxanthin, nostoxanthin) concentration increased 2.7–4.7 times compared to LEDWL conditions. The productivity of culture was double under WLFRL compared with LEDWL conditions. No significant changes in lipid, protein, and carbohydrate concentrations were found in the two different light conditions. The results are important for informing on optimum biomass cultivation of this species for biomass production and bioactive product development.

scholarly journals Green and Red Light Reduces the Disease Severity by Pseudomonas cichorii JBC1 in Tomato Plants via Upregulation of Defense-Related Gene Expression

2015 ◽  
Vol 105 (4) ◽  
pp. 412-418 ◽  
Author(s):  
Rajalingam Nagendran ◽  
Yong Hoon Lee
Keyword(s):  
Disease Severity ◽  
White Light ◽  
Disease Incidence ◽  
Red Light ◽  
Light Conditions ◽  
Pseudomonas Cichorii ◽  
Tomato Plants ◽  
Tomato Seedlings ◽  
Pathogenesis Related Protein ◽  
Dark Conditions

Light influences many physiological processes in most organisms. To investigate the influence of light on plant and pathogen interaction, we challenged tomato seedlings with Pseudomonas cichorii JBC1 by flood inoculation and incubated the seedlings under different light conditions. Tomato seedlings exposed to green or red light showed a significant reduction in disease incidence compared with those grown under white light or dark conditions. To understand the underlying mechanisms, we investigated the effects of each light wavelength on P. cichorii JBC1 and tomato plants. Treatment with various light wavelengths at 120 µmol m–2s–1 revealed no significant difference in growth, swarming motility, or biofilm formation of the pathogen. In addition, when we vacuum-infiltrated P. cichorii JBC1 into tomato plants, green and red light also suppressed disease incidence which indicated that the reduced disease severity was not from direct influence of light on the pathogen. Significant upregulation of the defense-related genes, phenylalanine ammonia-lyase (PAL) and pathogenesis-related protein 1a (PR-1a) was observed in P. cichorii JBC1-infected tomato seedlings grown under green or red light compared with seedlings grown under white light or dark conditions. The results of this study indicate that light conditions can influence plant defense mechanisms. In particular, green and red light increase the resistance of tomato plants to infection by P. cichorii.

scholarly journals Ecophysiology of seed germination in Mediterranean geophytes. 1. Muscari spp

2002 ◽  
Vol 12 (3) ◽  
pp. 193-201 ◽  
Author(s):  
Maria A. Doussi ◽  
Costas A. Thanos
Keyword(s):  
Seed Germination ◽  
White Light ◽  
Mediterranean Climate ◽  
Germination Rate ◽  
Red Light ◽  
Rainfall Regime ◽  
Light Conditions ◽  
Rainy Period ◽  
Germination Characteristics ◽  
The Mediterranean

Ecophysiological aspects of seed germination were investigated in four Mediterranean geophytes of the genus Muscari (Liliaceae): M. comosum (tassel hyacinth), M. neglectum (common grape hyacinth), M. commutatum and M. weissii. Experiments were performed at constant temperatures in the dark and under temperature and light conditions simulating those prevailing in nature during November–January, i.e. well into the rainy season of the Mediterranean climate. In all species, no primary dormancy was revealed, and germination occurred in a rather narrow range of cool temperatures (optimum at 10 or 15°C) and at a remarkably slow rate; both germination characteristics seem to be associated with autumn/winter seed germination and seedling establishment. Such a postulated strategy is ecologically advantageous within an unpredictable rainfall regime, known to prevail during the start of the rainy period of the Mediterranean climate. This strategy may also explain the spread of germination of M. comosum seeds over two consecutive years, observed by Theophrastus. Far-red light, simulating light conditions under a dense canopy, resulted in only a slight delay of germination compared to dark controls. Diurnal white light, qualitatively simulating natural daylight, caused a significant decrease of the germination rate in all four species studied. Moreover, white light was found to suppress considerably final seed germination (photoinhibition) in M. weissii and M. neglectum; in the latter species, prolonged imbibition under white light also led to the induction of secondary dormancy.

scholarly journals Illumination Policies for Stichococcus sp. Cultures in an Optimally Operating Lab-Scale PBR toward the Directed Photosynthetic Production of Desired Products

2021 ◽  
Vol 13 (5) ◽  
pp. 2489
Author(s):  
Paraskevi Psachoulia ◽  
Christos Chatzidoukas
Keyword(s):  
Blue Light ◽  
White Light ◽  
Red Light ◽  
Biomass Concentration ◽  
Biomass Productivity ◽  
Metabolite Profile ◽  
Culture Conditions ◽  
Light Spectrum ◽  
Led Light ◽  
Red Led

The light spectrum effect on the cultivation efficiency of the microalgae strain Stichococcus sp. is explored, as a means of potentially intensifying the biomass productivity and regulating the cellular composition. Stichococcus sp. batch culture experiments, within a 3 L bench-top photobioreactor (PBR), are designed and implemented under different light spectrum profiles (i.e., cool white light (WL), cool white combined with red light (WRL), and cool white combined with blue light, (WBL)). The obtained results indicate that the studied strain is capable of adapting its metabolite profile to the light field to which it is exposed. The highest biomass concentration (3.5 g/L), combined with intense carbohydrate accumulation activity, resulting in a respective final concentration of 1.15 g/L was achieved within 17 days using exclusively cool white light of increasing intensity. The addition of blue light emitting diodes (LED) light, combined with appropriately selected culture conditions, contributed significantly to the massive synthesis and accumulation of lipids, resulting in a concentration of 1.43 g/L and a respective content of 46.13% w/w, with a distinct impact on biomass, carbohydrates and proteins productivity. Finally, a beneficial contribution of red LED light to the protein synthesis is recognized and this can be conditionally amplified provided nitrogen sufficiency in the culture medium.

Photosynthetic Adaptation in Synechococcus Cells

1982 ◽  
Vol 37 (11-12) ◽  
pp. 1075-1080 ◽  
Author(s):  
Günter Döhler ◽  
Jean-Claude Leclerc
Keyword(s):  
Chlorophyll A ◽  
Oxygen Evolution ◽  
Quantum Efficiency ◽  
Photosynthetic Pigments ◽  
White Light ◽  
Anacystis Nidulans ◽  
Total Chlorophyll ◽  
Light Conditions ◽  
Quantum Requirement ◽  
Photosynthetic Adaptation

Abstract The cyanobacterium Synechococcus (Anacystis nidulans, strain L 1401-1) grown under different light conditions showed variations in pigmentation. Ratios of photosynthetic pigments and the effect on quantum requirement and oxygen evolution were studied. An increase in the ratio of chlorophyll a forms with absorption maxima in the far red regime to total chlorophyll a forms was observed in cells grown in strong white light. The quantum efficiency of orange light (637 nm) - absorbed by phycocyanin - was higher after growth of Synechococcus in white than

Effects of light and temperature on germination of heteromorphic achenes of Bidens odorata (Asteraceae)

1991 ◽  
Vol 69 (3) ◽  
pp. 574-579 ◽  
Author(s):  
Lea Corkidi ◽  
Emmanuel Rincon ◽  
Carlos Vazquez-Yanes
Keyword(s):  
Key Words ◽  
White Light ◽  
Laboratory Experiments ◽  
Red Light ◽  
Germination Percentage ◽  
Light Conditions ◽  
Light Requirement ◽  
Physiological Basis ◽  
Dry Storage ◽  
Percent Germination

Bidens odorata Cav. (Asteraceae) is an annual weed with heteromorphic achenes that differ in size, weight, and shape within each capitulum. To investigate if the variability of the achene size was correlated with differences in the germination response, achenes were classified in three categories based on size (4, 5–6, and 7 mm), and laboratory experiments were conducted with freshly harvested and dry-stored seeds under several light and temperature conditions. For all conditions tested with fresh seeds, 7-mm achenes germinated faster and with a higher final germination percentage than 4-mm achenes. Germination was inhibited by darkness and far-red light conditions. Experiments conducted with different times of exposure to white light (1 min, 10 min, and 12 h) showed that 4-mm achenes required longer time of exposure to light to maximize their percent germination. However, 7-mm achenes reached similar total percent germination without regard to the period of illumination. Dry storage increased the percent germination significantly in the shorter achenes and altered the light requirement for germination differentially among the morphs. The results suggest a physiological basis of achene heteromorphism that might be related to colonization of different microenvironments. Key words: Bidens odorata, germination, heteromorphism, light, temperature.

scholarly journals The Preferences of Different Cultivars of Lettuce Seedlings (Lactuca sativa L.) for the Spectral Composition of Light

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1211
Author(s):  
Barbara Frąszczak ◽  
Monika Kula-Maximenko
Keyword(s):  
Chlorophyll Content ◽  
Blue Light ◽  
White Light ◽  
Leaf Shape ◽  
Red Light ◽  
Spectral Composition ◽  
Fresh Weight ◽  
Light Spectrum ◽  
Dark Green ◽  
Relative Chlorophyll Content

The spectrum of light significantly influences the growth of plants cultivated in closed systems. Five lettuce cultivars with different leaf colours were grown under white light (W, 170 μmol m−2 s−1) and under white light with the addition of red (W + R) or blue light (W + B) (230 μmol m−2 s−1). The plants were grown until they reached the seedling phase (30 days). Each cultivar reacted differently to the light spectrum applied. The red-leaved cultivar exhibited the strongest plasticity in response to the spectrum. The blue light stimulated the growth of the leaf surface in all the plants. The red light negatively influenced the length of leaves in the cultivars, but it positively affected their number in red and dark-green lettuce. It also increased the relative chlorophyll content and fresh weight gain in the cultivars containing anthocyanins. When the cultivars were grown under white light, they had longer leaves and higher value of the leaf shape index. The light-green cultivars had a greater fresh weight. Both the addition of blue and red light significantly increased the relative chlorophyll content in the dark-green cultivar. The spectrum enhanced with blue light had positive influence on most of the parameters under analysis in butter lettuce cultivars. These cultivars were also characterised by the highest absorbance of blue light.

Effects of electron-withdrawing groups in imidazole-phenanthroline ligands and their influence on the photophysical properties of EuIII complexes for white light-emitting diodes

2017 ◽  
Vol 41 (18) ◽  
pp. 9826-9839 ◽  
Author(s):  
Boddula Rajamouli ◽  
Rachna Devi ◽  
Abhijeet Mohanty ◽  
Venkata Krishnan ◽  
Sivakumar Vaidyanathan
Keyword(s):  
Thin Film ◽  
Quantum Yield ◽  
White Light ◽  
Light Emitting Diode ◽  
Photophysical Properties ◽  
Red Light ◽  
Europium Complexes ◽  
Light Emitting ◽  
White Light Emitting Diodes ◽  
Phenanthroline Ligands

The red light emitting diode (LED) was fabricated by using europium complexes with InGaN LED (395 nm) and shown digital images, corresponding CIE color coordinates (red region) as well as obtained highest quantum yield of the thin film (78.7%).

(K0.5Na0.5)NbO3:Eu3+/Bi3+: a novel, highly efficient, red light-emitting material with superior water resistance behavior

RSC Advances ◽  
2015 ◽  
Vol 5 (6) ◽  
pp. 4707-4715 ◽  
Author(s):  
Qiwei Zhang ◽  
Haiqin Sun ◽  
Tao Kuang ◽  
Ruiguang Xing ◽  
Xihong Hao
Keyword(s):  
Blue Light ◽  
White Light ◽  
High Performance ◽  
Water Resistance ◽  
Light Emitting Diodes ◽  
Red Light ◽  
Light Emitting ◽  
Highly Efficient ◽  
White Light Emitting Diodes

Materials emitting red light (∼611 nm) under excitation with blue light (440–470 nm) are highly desired for fabricating high-performance white light-emitting diodes (LEDs).

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