Green Light-emitting Diode Light Research Articles

Efficient Photodegradation of Eriochrome Black-T by a Trimetallic Magnetic Self-Synthesized Nanophotocatalyst Based on Zn/Au/Fe-Embedded Poly(vinyl alcohol).

This study presents a novel photocatalytic system for photocatalytic degradation of Eriochrome black-T (EBT) dye via green light-emitting diode (LED) light exposure. This photocatalyst is comprised of nanoscale components, i.e., poly(vinyl alcohol) (PVA), magnetic iron oxide nanoparticles (Fe3O4 NPs), gold NPs (Au NPs), and zinc oxide nanorods (ZnO NRs), rendering an active high surface area. The most highlighted property from the structural facet is the superparamagnetic behavior of Fe3O4 NPs, which provides a facile collection of magnetic photocatalyst NPs from the reaction flask and is successfully recycled eight times without considerable reduction in catalytic behavior. Briefly, the photocatalytic degradation at its highest efficiency reached 51.4% (10 ppm dye solution, 5.0 mL) and 64.75% (8 ppm dye solution, 5.0 mL) utilizing 10 mg of the designed photocatalyst (formulated as Fe3O4@PVA-Au/ZnO), a magnetic photocatalytic system under green LED light (7 W, 526 nm) exposure for 60 min. Besides, the photocatalytic degradation mechanism of the EBT dye by the as-prepared photocatalyst was proposed. Based on the obtained results, the presented photocatalytic method was recommended for scaling up and large-scale exploitation for the purification of the water resources.

Influence of Different Light-Emitting Diode Colors on Growth and Phycobiliprotein Generation of Arthrospira platensis.

Light-emitting diodes (LED) can be utilized as tailorable artificial light sources for the cultivation of cyanobacteria such as Arthrospira platensis (AP). To study the influence of different LED light colors on phototrophic growth and biomass composition, AP was cultured in closed bioreactors and exposed to red, green, blue, or white LED lights. The illumination with red LED light resulted in the highest cell growth and highest cell densities compared to all other light sources (order of cell densities: red > white > green > blue LED light). In contrast, the highest phycocyanin concentrations were found when AP was cultured under blue LED light (e.g., order of concentrations: blue > white > red > green LED light). LED-blue light stimulated the accumulation of nitrogen compounds in the form of phycobiliproteins at the expense of cell growth. The results of the study revealed that exposure to different LED light colors can improve the quality and quantity of the biomass gained in AP cultures.

The effects of light colour on female rabbit reproductive performance and the expression of key genes in follicular development.

The purpose of this study was to analyse the effects of light colour on rabbit reproductive performance and the expression of key follicular development genes. Rabbits (n = 1,068, 5 months old, 3.6–4.4 kg live body weight) were divided randomly into four groups, housed individually in wire mesh cages and exposed to red, green, blue, and white light-emitting diode (LED) light (control). The lighting schedule was 16 L : 8 D-15 d / 150 lx / 6:00 am–22:00 pm (3 d preartificial insemination to 12 d postartificial insemination). Red light and white light affected the conception rate and kindling rate and increased the total litter size at birth (p < 0.05). The effects of red light on litter size at weaning, litter weight at weaning, and individual weight at weaning increased compared with the green and blue groups. The effects of red light on live litter size at birth were increased compared with those in the blue group (p < 0.05). Compared to white light, green and blue light reduced the number of secondary follicles (p < 0.05). Compared to red light, green and blue light reduced the number of tertiary follicles (p < 0.05). Compared with white light, red LED light resulted in greater ovarian follicle stimulating hormone receptor and luteinizing hormone receptor mRNA expression (p < 0.05). Compared with green and blue LED light, red LED light resulted in greater B-cell lymphom-2 mRNA expression (p < 0.05). Compared with green LED light, red LED light inhibited FOXO1 mRNA expression in rabbit ovaries (p < 0.05). Red light can affect the reproductive performance of female rabbits and the expression of key genes for follicular development.

Effects of green light emitting diode light during incubation and dietary organic macro and trace minerals during rearing on tibia characteristics of broiler chickens at slaughter age

This study was designed to evaluate the effects of green light emitting diode (LED) light during incubation and dietary organic macro and trace minerals during rearing on tibia morphological, biophysical, and mechanical characteristics of broiler chickens at slaughter age. The experiment was setup as a 2 × 2 × 2 factorial arrangement, with the following treatments: 1) light during incubation (green LED light or darkness), 2) macro mineral source during rearing (organic or inorganic Ca and P), and 3) trace mineral source during rearing (organic or inorganic Fe, Cu, Mn, Zn, and Se). A total of 2,400 eggs (Ross 308) were either incubated under green LED light (16L:8D) or in complete darkness. After hatch, a total of 864 male broiler chickens were reared until slaughter age (day 42) and provided with 1 of 4 diets, differing in macro and/or trace mineral source. During rearing, the experiment had a complete randomized block design with 9 replicate pens per treatment and 12 chickens per pen. At slaughter age (day 42), 2 chickens per replicate were randomly selected and tibia bones were obtained. Tibia weight, length, thickness, osseous volume, pore volume, total volume, mineral content, mineral density, ultimate strength, and stiffness were determined. Green LED light during incubation did not affect any of the tibia characteristics. Dietary organic macro minerals positively affected most of the tibia morphological, biophysical, and mechanical characteristics compared to the inorganic macro minerals, whereas trace mineral sources did not affect tibia characteristics. It can be concluded that dietary organic macro minerals Ca and P stimulated tibia characteristics, whereas green LED light during incubation and dietary trace minerals during rearing did not affect tibia characteristics, locomotion, or leg disorders.

Effect of several factors on the phototactic response of the oriental armyworm, Mythimna separata (Lepidoptera: Noctuidae)

Abstract Recently, light traps equipped with light-emitting diode (LED) lights have been used to monitor and control nocturnal insect pests. The oriental armyworm, Mythimna separata Walker, is an important cosmopolitan agriculture pest. The phototactic responses of nocturnal insects, including moths are influenced by abiotic and biological factors. The present study aimed to evaluate the phototactic response to different wavelength LED lights to determine the wavelength to which M. separata adults are most sensitive, and then identify the effects of several factors on the phototactic response. Our experiments revealed that M. separata adult moths had a significantly higher attraction rate to the green (520 nm) LED light compared with other LED lights, the green LED light was 1.28 times more attractive the moths than the commercial double-wave light used as a control. The phototactic response of the adult moths was significantly influenced by several factors, including adaption time in darkness, age, mating status and sexuality. These findings suggest that using a green LED light as a light source in trap could be effective in monitoring or controlling M. separata moths. Our results may provide a theoretical and scientific basis for improving the light trap technique for M. separata moths.

Photobiological (LED light)-mediated fermentation of blueberry (Vaccinium corymbosum L.) fruit with probiotic bacteria to yield bioactive compounds

The aim of this study was to investigate if fermentation of blueberry fruit by Bacillus amyloliquefaciens and Lactobacillus brevis under green, red, blue, and white light emitting diode (LED) illumination or sunlight could yield functionalized products for biomedical applications. Fermentation by both bacterial species under white and green LED light and sunlight resulted in increased viable cell count of the bacteria as well as total phenol and flavonoid contents over 72 h of fermentation. Blue and red LED light fermentation and that in darkness resulted in fermented samples with moderate anti-bacterial activity based on minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) as well as antioxidant and cytotoxic assays compared to fermentations under other light sources. In addition, Fourier transform infrared spectroscopy (FT-IR) was performed to determine the functional groups in the non-fermented (control) and fermented products. Sunlight and white, red, and green LED light-fermented extracts contained alcohol, acid, and phenol groups, as well as aliphatic amines. The results of this study clearly indicate that fermentation of blueberries with probiotic bacteria under various LED light sources can yield compounds that can be used in cosmetic and value-added food products.

Growth Responses of Potato Plantlets Cultured In Vitro under Different Colors Light-Emitting Diodes (LEDs)

This exploration work target was to upgrade the micropropagation of potato cultivars through the utilizationof new light sources in the development rooms. The experiment consisted of two potato cultivars (Diamant and agria),and five light sources (white, blue, green and red LEDs; and white fluorescent lights). The explants comprised of nodalsegments containing one bud, segregated from plantlets developed in vitro. The experimental design was completelyrandomized arranged in a 2x5 factorial, with 4 replications. Each experimental unit consisted of a flask with fiveexplants. Three 28-day successive subcultures were done in MS medium and incubated under controlled conditions(temperature = 25+2oC; photoperiod = 16 hours; light intensity = 20 μmol m-2 s-1). Toward the finish of everysubculture, plantlet length, number of nodes per plantlet, internode length and plantlet fresh weight were assessed. Afterthe second subculture, differences were found among the two potato cultivars developed in vitro: Agria performedbetter than Diamant in most plantlet growth parameters. Different light sources influenced the potato plantletdevelopment: red and green LEDs were the most and least prescribed for plantlet advancement respectively, in view ofthe after effects of bud number per plantlet, plantlet length. Photosynthetic pigment contents were significantly differentunder the different light treatments. Chlorophyll a, b and carotenoids were higher in plantlets grown under Red, and lessin plantlets under green LED light.

Light-Emitting Diode Spectral Sensitivity Relationship with Growth, Feed Intake, Meat, and Manure Characteristics in Broilers

Abstract. Light-emitting diode (LED) light sources have high potential for replacing traditional incandescent lamps in broiler production. LEDs with short wavelengths (480 and 560 nm) have been reported to stimulate broiler growth. However, short-wavelength stimuli might also have potential negative effects on husbandry workers, which has restricted the application of LED technology to broiler production. In this study, we investigated the effect of human-friendly yellow LED light (580 nm), which is close to the wavelength of 560 nm and acceptable for humans, on broiler growth response. We further evaluated the effects of various LED lights on the feed intake and manure characteristics of broilers. The following seven light treatments were tested: red LED light (R group), yellow LED light (Y group), green LED light (G group), blue LED light (B group), purple LED light (P group), white LED light (W group), and incandescent bulb light (I group). We used a 12:12 light:dark cycle, as described in our previous study. The feed and water usage of each group were recorded daily, while body weight and manure weight were determined weekly. Manure from each group was sampled for subsequent analysis. We found that the effects of the LEDs on broiler growth were age-related. Broilers in the Y, G, and B groups had similar body weights. However, the relative body weight gain ratio of broilers in the Y group was always greater than those of broilers in the other groups, particularly those in the I group (p = 0.003). The mass ratio of water usage to feed consumption was highest in the R group, whereas the Y group had the lowest mass ratio. Analysis of manure characteristics showed that manure production was positively correlated with feed intake, and broilers in the Y group produced the lowest amount of manure. The water intake of the broilers and the moisture content of the manure were also positively correlated, suggesting that the lower moisture content of the Y group manure might be caused by decreased water intake. These findings suggest that human-friendly yellow LED light might be a good alternative to green LED, blue LED, and incandescent lamps and can successfully be applied to broiler production.

Enhanced biomass production and lipid accumulation of Picochlorum atomus using light-emitting diodes (LEDs)

The effects of light-emitting diode (LED) wavelength, light intensity, nitrate concentration, and time of exposure to different LED wavelength stresses in a two-phase culture on lipid production were evaluated in the microalga, Picochlorum atomus. The biomass produced by red LED light was higher than that produced by purple, blue, green, or yellow LED and fluorescent lights from first phase of two-phase culture. The highest lipid production of P. atomus was 50.3% (w/w) with green LED light at 2days of second phase as light stress. Fatty acid analysis of the microalgae showed that palmitic acid (C16:0) and linolenic acid (C18:3) accounted for 84–88% (w/w) of total fatty acids from P. atomus. The two-phase culture of P. atomus is suitable for biofuel production due to higher lipid productivity and favorable fatty acid composition.

Variations in the antioxidant system and circadian rhythms of goldfish, Carassius auratus, exposed to ammonia: profile of the effects of green LED spectra

The present study evaluated effects of green light emitting diode (LED) spectra on oxidative stress and circadian rhythms in goldfish exposed to various concentrations (0.25 and 0.5 mg/L) of NH3, under a white fluorescent bulb (control; simulated natural period) and green LED light. We measured mRNA expression and activity of antioxidant enzymes (superoxide dismutase and catalase) and mRNA expression of circadian rhythms (period 2), in addition to levels of plasma hydrogen peroxide, cortisol and melatonin. Damage to nuclear DNA was assessed using the comet assay. All stress indicators and melatonin were significantly lower in the green LED group than in the control group. With an increase in the concentration of ammonia, the observed effects became even more significant and generally increased with time. Comparatively, damage to the nuclear DNA was greater in the 0.5 mg/L NH3 group, and lower in the green LED group. The Period 2 mRNA expression reduced as increasing ammonia treatment but increased as green LED exposed. We have suggested that Green LED reduced levels of oxidative stress, which suggests an antioxidant effect against NH3 toxicity. Additionally, ammonia is affected the circadian rhythms and the green LED wavelength is able to regulate effectively the circadian rhythm.

Effect of Light Intensity and Wavelength on Diurnal Activity of the Banded Coral Shrimp Stenopus hispidus (Decapoda, Stenopodidae): A Possible Adaptation for a Cleaner Shrimp in Reef Environments

Most decapod crustaceans are nocturnal. However, because cleaner shrimp at cleaning stations act in concert with their hosts, they clean debris and parasites off the body surfaces of diurnal hosts during daytime. It is not known how cleaner shrimp physiologically accommodate diurnal environments and perform cleaning behaviors. We examined the effect of light cues on the daily rhythmicity of the banded coral shrimp Stenopus hispidus (Decapoda, Stenopodidae), a cleaner shrimp in coral reefs. Shrimp were individually kept in aquaria under conditions of 12-hr light and 12-hr darkness (LD) and constant darkness (DD). Double-plotted actogram analyses revealed that shrimp under LD were active during scotophase and inactive during photophase. Locomotor rhythms were observed in most shrimp under DD. Periodogram analyses showed a weak circadian rhythm in shrimp under DD. Our results show that this species is nocturnal and that its locomotor activity is controlled primarily by the LD cycle. Day-night differences in locomotor activity were reduced in shrimp under LD with weak irradiance, and they remained active during photophase. Shrimp under LD using blue or green light-emitting diode light, but not red light-emitting diode light, showed a day-inactive and night-active rhythmicity. These results indicate that this species can be active under environments with low green and blue spectra—for example, during twilight hours, at depth, or on cloudy days—even during daytime, and this weakness of the circadian clock may be advantageous in their role as cleaner shrimp. It is concluded that in addition to the presence of visiting hosts, light conditions at cleaning stations are likely to influence cleaning activity.

Erythrosine-Mediated Photodynamic Inactivation of Bacteria and Yeast Using Green Light-Emitting Diode Light

Erythrosine, also known as FD & C Red No. 3, is a synthetic dye that has been used for food coloring and dental plaque detection. The objective of this study was to evaluate erythrosine as a viable photosensitizer in photodynamic inactivation (PDI) of bacteria and yeast. Cells were treated with erythrosine with or without acetic acid in the presence and absence of light. Erythrosine in the absence of light did not show any activity against the microorganisms. When treated with light, erythrosine was efficient in eradicating non-adherent (planktonic) Gram (+) bacteria and yeast. However, Gram (-) bacteria were less responsive to PDI. Addition of acetic acid was found to enhance the activity of erythrosine and significantly lower the survival of Gram (-) bacteria. This study demonstrated the potential applications of erythrosine in PDI and the potentiating effects of acetic acid.

LED Light Spectrum Affects the Photosynthetic Performance of Houttuynia Cordata Seedlings

We investigated the effects of light-emitting diodes (LED) with various light spectrum (white, red, yellow, green and blue) on photosynthesis of Houttuynia cordata seedlings. The seedlings were either cultivated under florescent lamp or under various LED lights. The leaves were collected and chlorophyll fluorescence parameters, the contents of chlorophyll, soluble sugar and relative water were measured, chloroplasts were observed as well. The results showed chlorophyll fluorescence parameters as Fv/Fm, qP and qY values were the highest under blue LED light and the values were the lowest under green LED light. Red LED light resulted in the enhanced chlorophyll content compared with the other LED lights, and the chl a/chl b ratio did not change significantly among LED treatments. The soluble sugar content was not significantly different among the treatments. The red LED increased relative water content and the green LED decreased the water content. Observation of chloroplasts in the leaves of Houttuynia cordata seedlings showed chloroplast number and distribution were altered by various light spectrum where chloroplasts were smaller under blue LED, and appeared to be more scattered under red LED. Our results indicated that photosynthesis of Houttuynia cordata seedlings respond differently to various light spectrum emitted by florescent lamp and LED

Impact of lighting on poultry reproduction and recent advances.

Abstract Different wavelengths of visible light spectrum influence the reproductive system of domestic avian species. Light perceived by the retina is involved in growth and behaviour whereas light perceived by the hypothalamus is involved in reproduction through photosensitive cells in the brain (extra-retinal photoreceptors) and it varies with intensity of different wavelengths of light. Red spectrum of light with 675 nm of wavelengths is more gonadostimulatory than shorter wavelengths of 450-475 nm of light. Recent studies indicate that the hypothalamic opsins are involved in avian photoreception. Non-mammalian vertebrates detect light by deep brain photoreceptors that lie outside the retina and pineal gland to regulate seasonal cycle of reproduction. It was reported that opsin is a deep-brain photoreceptive molecule in the avian brain that regulate seasonal reproduction in birds. Lighting recommendations should be based on local environmental conditions, house type, light requirements for pullets, growers, broilers, layers and overall stockman objectives. Lighting programmes that are inappropriately employed may impair average daily gain and compromise flock performance. Careful observations of flock performance, nutrient density and intake are also important in designing lighting programmes in broilers. Layer and broiler lighting programmes in concert with the proper genetics, environment, nutrition and management create the best in welfare for the animal and performance for the integrator. Light-emitting diode (LED) lighting in poultry facilities is cost effective and could increase egg production in layers and early body weight gain in broilers exposed to red and green LED light, respectively.

The effect of various wavelengths of light from light-emitting diodes on the antioxidant system of marine cyanobacteria, Synechococcus sp.

This study investigated the antioxidant system and the growth of marine cyanobacteria, Synechococcus sp., illuminated by white (350–700 nm), red (630 nm), green (530 nm) and blue (450 nm) light-emitting diodes (LEDs) during 8 days of cultivation. We measured dry weight, total lipid concentration, antioxidant enzyme (superoxide dismutase, catalase and glutathione peroxidase) activities, lipid peroxidation and H2O2 levels. In red and green LED light, dry weight and total lipid concentration were significantly higher than under other light spectra. Furthermore, antioxidant enzyme activities were significantly higher in red light than in the other light spectra evaluated. However, the H2O2 level in red light was significantly lower than that found under other light spectra. These results indicated that red LEDs inhibit oxidative stress and enhance antioxidant function in cultured Synechococcus sp.

Effect of green light wavelength and intensity on photomorphogenesis and photosynthesis in Lactuca sativa

In this study, the effects of green light-emitting diodes (LEDs) with different peak wavelengths and light intensities on lettuce growth and photosynthesis were evaluated. The green LEDs used were G510 (peak wavelength: 510 nm; band width at half peak height: 18 nm), G520 (524 nm; 30 nm) and G530 (532 nm; 36 nm) at a photosynthetic photon flux (PPF) of 100, 200 and 300 μmol m −2 s −1, respectively (maximum output of G530 was PPF 260). Shoot and root growth in lettuce plants irradiated with green LED light at PPF 100 decreased compared with white fluorescent light, but root growth of plants irradiated with green LED light at PPF 200 increased, and shoot growth of plants grown under G510 at PPF 300 was the highest of all light sources. Leaf photosynthetic rate (Pn) of plants irradiated with green LED light at PPF 200 was dramatically higher than that at PPF 100, and the Pn of plants irradiated with G510 was the highest of all light sources. These results indicated that high-intensity green LED light was effective to promote plant growth and, in particular, short-wavelength green light was available for active plant growth.