scholarly journals Combined artificial high-silicate medium and LED illumination promote carotenoid accumulation in the marine diatom Phaeodactylum tricornutum

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Zhiqian Yi ◽  
Yixi Su ◽  
Paulina Cherek ◽  
David R. Nelson ◽  
Jianping Lin ◽  
...  
Keyword(s):  
Light Intensity ◽  
Phaeodactylum Tricornutum ◽  
Red Light ◽  
Monochromatic Light ◽  
Biomass Productivity ◽  
Marine Diatom ◽  
Light Illumination ◽  
Scale Production ◽  
Red Led ◽  
High Silicate

Abstract Background Diatoms, which can accumulate large amounts of carotenoids, are a major group of microalgae and the dominant primary producer in marine environments. Phaeodactylum tricornutum, a model diatom species, acquires little silicon for its growth although silicon is known to contribute to gene regulation and play an important role in diatom intracellular metabolism. In this study, we explored the effects of artificial high-silicate medium (i.e. 3.0 mM sodium metasilicate) and LED illumination conditions on the growth rate and pigment accumulation in P. tricornutum, which is the only known species so far that can grow without silicate. It’s well known that light-emitting diodes (LEDs) as novel illuminants are emerging to be superior monochromatic light sources for algal cultivation with defined and efficient red and blue lights. Results Firstly, we cultivated P. tricornutum in a synthetic medium supplemented with either 0.3 mM or 3.0 mM silicate. The morphology and size of diatom cells were examined: the proportion of the oval and triradiate cells decreased while the fusiform cells increased with more silicate addition in high-silicate medium; the average length of fusiform cells also slightly changed from 14.33 µm in 0.3 mM silicate medium to 12.20 µm in 3.0 mM silicate medium. Then we cultivated P. tricornutum under various intensities of red light in combination with the two different levels of silicate in the medium. Higher biomass productivity also achieved in 3.0 mM silicate medium than in 0.3 mM silicate medium under red LED light irradiation at 128 μmol/m2/s or higher light intensity. Increasing silicate reversed the down-regulation of fucoxanthin and chlorophyll a under high red-light illumination (i.e. 255 μmol/m2/s). When doubling the light intensity, fucoxanthin content decreased under red light but increased under combined red and blue (50:50) lights while chlorophyll a content reduced under both conditions. Fucoxanthin accumulation and biomass productivity increased with enhanced red and blue (50:50) lights. Conclusion High-silicate medium and blue light increased biomass and fucoxanthin production in P. tricornutum under high light conditions and this strategy may be beneficial for large-scale production of fucoxanthin in diatoms.

Pilot-scale production of antibacterial substances by the marine diatom Phaeodactylum tricornutum Bohlin

2018 ◽  
Vol 32 ◽  
pp. 113-120 ◽  
Author(s):  
Song Wang ◽  
Inamullah Hakeem Said ◽  
Candice Thorstenson ◽  
Claudia Thomsen ◽  
Matthias S. Ullrich ◽  
...  
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Pilot Scale ◽  
Marine Diatom ◽  
Scale Production ◽  
Pilot Scale Production

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.

scholarly journals Growth, biomass and lipid productivity of a newly isolated tropical marine diatom, Skeletonema sp. UHO29, under different light intensities

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Indrayani Indrayani ◽  
Haslianti Haslianti ◽  
Asmariani Asmariani ◽  
Wellem Muskita ◽  
Abdul Muis Balubi
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
High Growth ◽  
Biomass Productivity ◽  
Dry Weight ◽  
High Light Intensity ◽  
High Growth Rate ◽  
Lipid Productivity ◽  
Marine Diatom ◽  
Light Intensities

Abstract. Indrayani I, Haslianti H, Asmariani A, Muskita WH, Balubi M. 2020. Growth, biomass and lipid productivity of a newly isolated tropical marine diatom, Skeletonema sp. UHO29, under different light intensities. Biodiversitas 21: 1498-1503. Light is one of the important factors affecting growth and biochemical composition of microalgae. The aim of this study was to determine growth, biomass and lipid productivity of a newly isolated marine diatom, Skeletonema sp.UHO29 under different light intensities. The Skeletonema sp. was cultured in 300 mL conical flasks containing 150 mL of f/2 medium under three different light intensities (28, 60 and 110 μmol photons m-2 s-1 ) with three replications. The cultures were incubated under ambient room temperatures, and a cycle of 12 hours light and 12 hours dark, in batch modes for two weeks. The results showed that the highest specific growth rate (0.56 d-1) was achieved at the highest light intensity (110 μmol photons m-2 s-1) and the lowest (0.11 d-1) was obtained at the lowest light intensity (28 μmol photons m-2 s-1). The highest biomass yield (0.62 g L-1) and biomass productivity (0.34 g L-1 d-1) was achieved at the highest light intensity. However, the highest lipid yield (0.175 g L-1), lipid content (28.78% ash-free dry weight) and lipid productivity (0.067 g L-1 d-1) were achieved at medium light intensity. The alga prefers high light intensity for higher growth rate and biomass productivity but it produces more lipids at medium light intensity. This study indicated that the Skeletonema sp.UHO29 is a potential species for outdoor mass cultivation and is a promising microalgal strain for use as a biodiesel feedstock due to its high growth rate, high biomass and lipid productivity.

An Investigation Into the Optothermal Behavior of a High Power Red Light Emitting Diode: Impact of an Optical Path

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Ahmet Mete Muslu ◽  
Burak Ozluk ◽  
Mehmet Arik
Keyword(s):  
Computational Models ◽  
Red Light ◽  
Monochromatic Light ◽  
Junction Temperature ◽  
Normal Operation ◽  
Imaging Method ◽  
Light Emitting ◽  
Wide Range ◽  
Red Led ◽  
The Impact

Abstract Monochromatic light emitting diodes (LEDs) are getting more attention day by day for a very wide range of applications such as general lighting, signage, automotive lighting, display, water purification, and skin imaging. While they are taking place in a large number of applications, thermal challenges associated with the operation of LEDs have become a significant issue to address since their performance is greatly affected by thermal conditions. Thus, this study focuses on identifying thermal, optical, and electrical characteristics of an AlGaInP-based red LED considering the impact of the LED dome on the chip performance. The junction temperature measurement results obtained with forward voltage change method were validated with thermal imaging method (TIM) and computational models. It was observed that the LED dome may critically affect the thermal, optical, and electrical behaviors of the LED chip. In fact, a 3.7% increase in junction temperature and a 6.1% drop in optical conversion efficiency were found at the normal operation of the red LED after the LED dome was removed. The results were also compared with a blue LED, and lower junction temperatures were measured for the red LED at each driving current. The difference in junction temperature became even more noticeable at higher driving currents. Results have shown a good agreement between three different methods with a maximum variation of 6.9%.

scholarly journals Morphological and Physiological Responses of Cucumber Seedlings to Supplemental LED Light under Extremely Low Irradiance

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1698
Author(s):  
Yiting Zhang ◽  
Hao Dong ◽  
Shiwei Song ◽  
Wei Su ◽  
Houcheng Liu
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Soluble Sugar ◽  
Red Light ◽  
Seedling Stage ◽  
Stem Diameter ◽  
Growth Stages ◽  
Led Light ◽  
Cucumber Seedlings ◽  
Red Led

In order to inhibit spindling growth and improve quality of cucumber seedlings under low irradiance, effects of supplemental light-emitting diodes (LED) light (SL) on morphological and physiological characteristics of cucumber seedlings at different growth stages under extremely low irradiance (ELI) were investigated. Supplementary monochromatic, dichromatic and trichromatic LED light on cucumber seedlings were conducted in experiment one, and supplements of combination ratios and intensity of blue and red LED light (RB) were conducted in experiment two. The morphological and physiological parameters of cucumber seedlings were promoted effectively by supplemental monochromatic red light or dichromatic containing red light (RB and RG) under ELI as early as one-leaf seedling stage, as demonstrated by suppressed length of hypocotyl and first internode, increased stem diameter and biomass, higher net photosynthetic rate (Pn) and soluble sugar content. Monochromatic or additional green light was not beneficial to cucumber seedlings under the ELI. The length of shoot and hypocotyl decreased, while stem diameter and leaf area increased as early as one-leaf seedling stage by RB SL. Root activities, root–shoot ratio, activities of catalase (CAT) and peroxidase (POD), as well as palisade–spongy ratio in the leaf of cucumber seedlings were promoted effectively by increasing blue light proportion (1R1B/1R2B). Increasing light intensity (50/75) enhanced soluble sugar accumulation in leaves. There were synergistic effects of RB ratio and light intensity on increasing stem diameter, leaf area, seedling index and decreasing hypocotyl cell area of the vertical section. In conclusion, 1R2B-75 may be the optimal SL to inhibit spindling growth of cucumber seedlings under ELI condition.

scholarly journals System Responses to Equal Doses of Photosynthetically Usable Radiation of Blue, Green, and Red Light in the Marine Diatom Phaeodactylum tricornutum

PLoS ONE ◽  
2014 ◽  
Vol 9 (12) ◽  
pp. e114211 ◽  
Author(s):  
Kristin Collier Valle ◽  
Marianne Nymark ◽  
Inga Aamot ◽  
Kasper Hancke ◽  
Per Winge ◽  
...  
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Red Light ◽  
Marine Diatom

scholarly journals Growth of Haematococcus pluvialis on a Small-Scale Angled Porous Substrate Photobioreactor for Green Stage Biomass

2021 ◽  
Vol 11 (4) ◽  
pp. 1788
Author(s):  
Thanh-Tri Do ◽  
Binh-Nguyen Ong ◽  
Tuan-Loc Le ◽  
Thanh-Cong Nguyen ◽  
Bich-Huy Tran-Thi ◽  
...  
Keyword(s):  
Light Intensity ◽  
Algal Biomass ◽  
Haematococcus Pluvialis ◽  
Biomass Productivity ◽  
Pilot Scale ◽  
Small Scale ◽  
Porous Substrate ◽  
Low Light ◽  
Green Algal ◽  
Green Stage

In the production of astaxanthin from Haematococcus pluvialis, the process of growing algal biomass in the vegetative green stage is an indispensable step in both suspended and immobilized cultivations. The green algal biomass is usually cultured in a suspension under a low light intensity. However, for astaxanthin accumulation, the microalgae need to be centrifuged and transferred to a new medium or culture system, a significant difficulty when upscaling astaxanthin production. In this research, a small-scale angled twin-layer porous substrate photobioreactor (TL-PSBR) was used to cultivate green stage biomass of H. pluvialis. Under low light intensities of 20–80 µmol photons m−2·s−1, algae in the biofilm consisted exclusively of non-motile vegetative cells (green palmella cells) after ten days of culturing. The optimal initial biomass density was 6.5 g·m−2, and the dry biomass productivity at a light intensity of 80 µmol photons m−2·s−1 was 6.5 g·m−2·d−1. The green stage biomass of H. pluvialis created in this small-scale angled TL-PSBR can be easily harvested and directly used as the source of material for the inoculation of a pilot-scale TL-PSBR for the production of astaxanthin.

scholarly journals Artificial complementary chromatic acclimation gene expression system in Escherichia coli

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Dwi Ariyanti ◽  
Kazunori Ikebukuro ◽  
Koji Sode
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Light Exposure ◽  
Expression System ◽  
Red Light ◽  
Green Light ◽  
Light Illumination ◽  
Multiple Gene ◽  
Gene Expression System ◽  
Chromatic Acclimation

Abstract Background The development of multiple gene expression systems, especially those based on the physical signals, such as multiple color light irradiations, is challenging. Complementary chromatic acclimation (CCA), a photoreversible process that facilitates the control of cellular expression using light of different wavelengths in cyanobacteria, is one example. In this study, an artificial CCA systems, inspired by type III CCA light-regulated gene expression, was designed by employing a single photosensor system, the CcaS/CcaR green light gene expression system derived from Synechocystis sp. PCC6803, combined with G-box (the regulator recognized by activated CcaR), the cognate cpcG2 promoter, and the constitutively transcribed promoter, the PtrcΔLacO promoter. Results One G-box was inserted upstream of the cpcG2 promoter and a reporter gene, the rfp gene (green light-induced gene expression), and the other G-box was inserted between the PtrcΔLacO promoter and a reporter gene, the bfp gene (red light-induced gene expression). The Escherichia coli transformants with plasmid-encoded genes were evaluated at the transcriptional and translational levels under red or green light illumination. Under green light illumination, the transcription and translation of the rfp gene were observed, whereas the expression of the bfp gene was repressed. Under red light illumination, the transcription and translation of the bfp gene were observed, whereas the expression of the rfp gene was repressed. During the red and green light exposure cycles at every 6 h, BFP expression increased under red light exposure while RFP expression was repressed, and RFP expression increased under green light exposure while BFP expression was repressed. Conclusion An artificial CCA system was developed to realize a multiple gene expression system, which was regulated by two colors, red and green lights, using a single photosensor system, the CcaS/CcaR system derived from Synechocystis sp. PCC6803, in E. coli. The artificial CCA system functioned repeatedly during red and green light exposure cycles. These results demonstrate the potential application of this CCA gene expression system for the production of multiple metabolites in a variety of microorganisms, such as cyanobacteria.

Sign in / Sign up

Export Citation Format

Share Document