scholarly journals Engineering the Unicellular Alga Phaeodactylum tricornutum for Enhancing Carotenoid Production

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 757 ◽  
Author(s):  
Francesco Manfellotto ◽  
Giulio Rocco Stella ◽  
Angela Falciatore ◽  
Christophe Brunet ◽  
Maria Immacolata Ferrante
Keyword(s):  
Phaeodactylum Tricornutum ◽  
High Performance ◽  
Biosynthetic Pathway ◽  
Carotenoid Content ◽  
Market Demand ◽  
Protein Levels ◽  
Transgenic Lines ◽  
Golden Color ◽  
Valuable Compounds ◽  
Carotenoid Biosynthetic Pathway

Microalgae represent a promising resource for the production of beneficial natural compounds due to their richness in secondary metabolites and easy cultivation. Carotenoids feature among distinctive compounds of many microalgae, including diatoms, which owe their golden color to the xanthophyll fucoxanthin. Carotenoids have antioxidant, anti-obesity and anti-inflammatory properties, and there is a considerable market demand for these compounds. Here, with the aim to increase the carotenoid content in the model diatom Phaeodactylum tricornutum, we exploited genetic transformation to overexpress genes involved in the carotenoid biosynthetic pathway. We produced transgenic lines over-expressing simultaneously one, two or three carotenoid biosynthetic genes, and evaluated changes in pigment content with high-performance liquid chromatography. Two triple transformants over-expressing the genes Violaxanthin de-epoxidase (Vde), Vde-related (Vdr) and Zeaxanthin epoxidase 3 (Zep3) showed an accumulation of carotenoids, with an increase in the fucoxanthin content up to four fold. Vde, Vdr and Zep3 mRNA and protein levels in the triple transformants were coherently increased. The exact role of these enzymes in the diatom carotenoid biosynthetic pathway is not completely elucidated nevertheless our strategy successfully modulated the carotenoid metabolism leading to an accumulation of valuable compounds, leading the way toward improved utilization of microalgae in the field of antioxidants.

scholarly journals Genotype × Environment Interactions for Potato Tuber Carotenoid Content

2010 ◽  
Vol 135 (3) ◽  
pp. 250-258 ◽  
Author(s):  
Kathleen G. Haynes ◽  
Beverly A. Clevidence ◽  
David Rao ◽  
Bryan T. Vinyard ◽  
J. Marion White
Keyword(s):  
High Performance Liquid Chromatography ◽  
Genetic Variation ◽  
High Performance ◽  
Biosynthetic Pathway ◽  
Carotenoid Content ◽  
Total Carotenoid ◽  
Fresh Weight ◽  
Total Carotenoid Content ◽  
The Stability ◽  
Carotenoid Biosynthetic Pathway

Consumption of carotenoid-containing foods can promote human health. Although yellow-fleshed potatoes (Solanum tuberosum) have a higher carotenoid content than white-fleshed potatoes, little is known about how growing environments may affect individual and total carotenoid content in different potato clones. The purposes of this study were to estimate the amount of genetic variability in potato for five xanthophyll carotenoids, their concentration, and to determine the stability of these carotenoids across environments. Nine white- or yellow-fleshed tetraploid clones were grown in Maine and Florida for 2 years. Carotenoids were extracted in acetone and analyzed by high-performance liquid chromatography. There were significant differences among clones for zeaxanthin, antheraxanthin, lutein, and total carotenoid content. There were significant clone × environment interactions for zeaxanthin, antheraxanthin, violaxanthin, neoxanthin, lutein, and total carotenoid. Broad-sense heritabilities (and their 95% confidence intervals) were 0.89 (0.79–0.98) for zeaxanthin, 0.93 (0.87–0.99) for antheraxanthin, 0.68 (0.14–0.92) for violaxanthin, 0.51 (0.00–0.88) for neoxanthin, 0.85 (0.70–0.97) for lutein, and 0.96 (0.89–0.99) for total carotenoid. Clonal mean total carotenoid content ranged from 101 to 511 μg/100 g fresh weight. A higher proportion of carotenoids were produced by the lycopene epsilon cyclase branch of the carotenoid biosynthetic pathway in white-fleshed than yellow-fleshed clones. Total carotenoid content in B2333-5 was significantly greater than in ‘Yukon Gold’. With genetic variation for individual and total carotenoid content in potatoes, improving the levels of carotenoids has been and should continue to be feasible; however, concentrations are likely to vary in different environments.

scholarly journals Arabidopsis OR proteins are the major posttranscriptional regulators of phytoene synthase in controlling carotenoid biosynthesis

2015 ◽  
Vol 112 (11) ◽  
pp. 3558-3563 ◽  
Author(s):  
Xiangjun Zhou ◽  
Ralf Welsch ◽  
Yong Yang ◽  
Daniel Álvarez ◽  
Matthias Riediger ◽  
...  
Keyword(s):  
Posttranscriptional Regulation ◽  
Biosynthetic Pathway ◽  
Carotenoid Biosynthesis ◽  
Transcript Abundance ◽  
Phytoene Synthase ◽  
Carotenoid Content ◽  
Compensatory Mechanism ◽  
Protein Levels ◽  
Mutual Regulation ◽  
Rate Limiting

Carotenoids are indispensable natural pigments to plants and humans. Phytoene synthase (PSY), the rate-limiting enzyme in the carotenoid biosynthetic pathway, and ORANGE (OR), a regulator of chromoplast differentiation and enhancer of carotenoid biosynthesis, represent two key proteins that control carotenoid biosynthesis and accumulation in plants. However, little is known about the mechanisms underlying their posttranscriptional regulation. Here we report that PSY and OR family proteins [Arabidopsis thaliana OR (AtOR) and AtOR-like] physically interacted with each other in plastids. We found that alteration of OR expression in Arabidopsis exerted minimal effect on PSY transcript abundance. However, overexpression of AtOR significantly increased the amount of enzymatically active PSY, whereas an ator ator-like double mutant exhibited a dramatically reduced PSY level. The results indicate that the OR proteins serve as the major posttranscriptional regulators of PSY. The ator or ator-like single mutant had little effect on PSY protein levels, which involves a compensatory mechanism and suggests partial functional redundancy. In addition, modification of PSY expression resulted in altered AtOR protein levels, corroborating a mutual regulation of PSY and OR. Carotenoid content showed a correlated change with OR-mediated PSY level, demonstrating the function of OR in controlling carotenoid biosynthesis by regulating PSY. Our findings reveal a novel mechanism by which carotenoid biosynthesis is controlled via posttranscriptional regulation of PSY in plants.

scholarly journals Impact of Environmental Factors on Stilbene Biosynthesis

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 90
Author(s):  
Alessio Valletta ◽  
Lorenzo Maria Iozia ◽  
Francesca Leonelli
Keyword(s):  
Environmental Factors ◽  
Biosynthetic Pathway ◽  
In Planta ◽  
Organ Cultures ◽  
Related Plant ◽  
Valuable Compounds ◽  
Stilbene Compounds ◽  
Stilbene Biosynthesis ◽  
Abiotic Environmental Factors

Stilbenes are a small family of polyphenolic secondary metabolites that can be found in several distantly related plant species. These compounds act as phytoalexins, playing a crucial role in plant defense against phytopathogens, as well as being involved in the adaptation of plants to abiotic environmental factors. Among stilbenes, trans-resveratrol is certainly the most popular and extensively studied for its health properties. In recent years, an increasing number of stilbene compounds were subjected to investigations concerning their bioactivity. This review presents the most updated knowledge of the stilbene biosynthetic pathway, also focusing on the role of several environmental factors in eliciting stilbenes biosynthesis. The effects of ultraviolet radiation, visible light, ultrasonication, mechanical stress, salt stress, drought, temperature, ozone, and biotic stress are reviewed in the context of enhancing stilbene biosynthesis, both in planta and in plant cell and organ cultures. This knowledge may shed some light on stilbene biological roles and represents a useful tool to increase the accumulation of these valuable compounds.

scholarly journals N-protein presents early in blood, dried blood and saliva during asymptomatic and symptomatic SARS-CoV-2 infection

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dandan Shan ◽  
Joseph M. Johnson ◽  
Syrena C. Fernandes ◽  
Hannah Suib ◽  
Soyoon Hwang ◽  
...  
Keyword(s):  
Single Molecule ◽  
High Performance ◽  
Point Of Care ◽  
Capillary Blood ◽  
Molecular Testing ◽  
Sample Collection ◽  
Protein Assay ◽  
N Protein ◽  
Protein Levels ◽  
Percent Agreement

AbstractThe COVID-19 pandemic continues to have an unprecedented impact on societies and economies worldwide. There remains an ongoing need for high-performance SARS-CoV-2 tests which may be broadly deployed for infection monitoring. Here we report a highly sensitive single molecule array (Simoa) immunoassay in development for detection of SARS-CoV-2 nucleocapsid protein (N-protein) in venous and capillary blood and saliva. In all matrices in the studies conducted to date we observe >98% negative percent agreement and >90% positive percent agreement with molecular testing for days 1–7 in symptomatic, asymptomatic, and pre-symptomatic PCR+ individuals. N-protein load decreases as anti-SARS-CoV-2 spike-IgG increases, and N-protein levels correlate with RT-PCR Ct-values in saliva, and between matched saliva and capillary blood samples. This Simoa SARS-CoV-2 N-protein assay effectively detects SARS-CoV-2 infection via measurement of antigen levels in blood or saliva, using non-invasive, swab-independent collection methods, offering potential for at home and point of care sample collection.

scholarly journals Low Dose of Fluoride in the Culture Medium of Cordyceps militaris Promotes Its Growth and Enhances Bioactives with Antioxidant and Anticancer Properties

2021 ◽  
Vol 7 (5) ◽  
pp. 342
Author(s):  
Xiaoshuai Li ◽  
Jia Wang ◽  
Huayue Zhang ◽  
Long Xiao ◽  
Zhongfang Lei ◽  
...  
Keyword(s):  
Low Dose ◽  
Radical Scavenging ◽  
Potassium Fluoride ◽  
Cordyceps Militaris ◽  
Carotenoid Content ◽  
Market Demand ◽  
Fruiting Bodies ◽  
Human Osteosarcoma Cells ◽  
Wide Range ◽  
Bioactive Ingredients

Cordyceps militaris possesses several compounds with medicinal properties, and is commonly used in traditional Chinese functional food and medicine for a variety of health benefits. Because of its rare occurrence in nature, the market demand for artificial C. militaris is on the rise. Furthermore, efforts to increase its bioactive ingredients have also been considered in research. In this study, we aimed to investigate the effect of fluoride on the growth and enrichment of bioactive compounds in C. militaris. A wide range of potassium fluoride concentrations (0, 0.001, 0.01, 0.1, and 1 mM) were added to the culture media as a source of fluoride during the cultivation of C. militaris fruiting bodies. The contents of fluorine and bioactive substances of the fruiting bodies in normal (NM) and fluorine-supplemented (FM) media were measured and compared. C. militaris raised in the growth medium supplemented with 0.01 mM potassium fluoride led to a 44.86% (1.55 ± 0.14 g/bottle) increase in biomass and a 23.43% (3161.38 ± 35.71 µg/g) increase in total carotenoid content in the fruiting bodies. Furthermore, a remarkable increase in superoxide dismutase-like activity (84.75 U/mg) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (IC50 = 2.59 mg/mL) was recorded. In human cancer cell-based assays, C. militaris raised in FM caused stronger cytotoxicity, apoptosis, and cell cycle arrest in human osteosarcoma cells. These results demonstrated that a low dose of fluoride could stimulate the growth of C. militaris fruiting bodies and enhance the production of bioactive ingredients that possess useful antioxidant and anticancer activities.

scholarly journals Palm Oil Carotenoids

1994 ◽  
Vol 15 (2) ◽  
pp. 1-8 ◽  
Author(s):  
Choo Yuen May
Keyword(s):  
Palm Oil ◽  
High Performance ◽  
Elaeis Guineensis ◽  
Provitamin A ◽  
Carotenoid Content ◽  
Crude Palm Oil ◽  
Alkyl Esters ◽  
Red Palm Oil ◽  
Potential Applications ◽  
Nutritional Effects

Crude palm oil is the richest natural plant source of carotenoids in terms of retinol (provitamin A) equivalent. This article reports on » the carotenoids found in palm oil, its fractions, byproducts, and derivatives from the Elaeis guineensis and E. oleifera palms, including their hybrids and a back-cross, as well as the carotenoids of pressed palm fibres, second-pressed oil, palm leaves, and palm-derived alkyl esters; » two novel procedures for preparing highly concentrated sources of carotenoids (>80,000 ppm), by recovery by palm alkyl esters, and by retention and concentration in deacidified and deodorized red palm oil; » the carotenoid content and profiles of the above sources obtained by high-performance liquid chromatography; and » nutritional effects of palm oil carotenoids and their potential applications for health promotion and disease prevention.

scholarly journals Differential Synthesis of Peritoxins and Precursors by Pathogenic Strains of the Fungus Periconia circinata

2001 ◽  
Vol 67 (12) ◽  
pp. 5721-5728 ◽  
Author(s):  
Alice C. L. Churchill ◽  
Larry D. Dunkle ◽  
Walter Silbert ◽  
Kevin J. Kennedy ◽  
Vlado Macko
Keyword(s):  
High Performance ◽  
Biosynthetic Pathway ◽  
Culture Conditions ◽  
Selective Toxicity ◽  
Photodiode Array Detection ◽  
Hybrid Molecules ◽  
Metabolite Profiles ◽  
Photodiode Array ◽  
Array Detection ◽  
Periconia Circinata

ABSTRACT Pathogenic strains of the soilborne fungus Periconia circinata produce peritoxins with host-selective toxicity against susceptible genotypes of sorghum. The peritoxins are low-molecular-weight, hybrid molecules consisting of a peptide and a chlorinated polyketide. Culture fluids from pathogenic, toxin-producing (Tox+) and nonpathogenic, non-toxin-producing (Tox−) strains were analyzed directly by gradient high-performance liquid chromatography (HPLC) with photodiode array detection and HPLC-mass spectrometry to detect intermediates and final products of the biosynthetic pathway. This approach allowed us to compare the metabolite profiles of Tox+ and Tox− strains. Peritoxins A and B and the biologically inactive intermediates,N-3-(E-pentenyl)-glutaroyl-aspartate, circinatin, and 7-chlorocircinatin, were detected only in culture fluids of the Tox+ strains. The latter two compounds were produced consistently by Tox+ strains regardless of the amount of peritoxins produced under various culture conditions. In summary, none of the known peritoxin-related metabolites were detected in Tox− strains, which suggests that these strains may lack one or more functional genes required for peritoxin biosynthesis.

scholarly journals Chemical Mutagenesis and Fluorescence-Based High-Throughput Screening for Enhanced Accumulation of Carotenoids in a Model Marine Diatom Phaeodactylum tricornutum

Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 272 ◽  
Author(s):  
Zhiqian Yi ◽  
Yixi Su ◽  
Maonian Xu ◽  
Andreas Bergmann ◽  
Saevar Ingthorsson ◽  
...  
Keyword(s):  
High Throughput ◽  
Metabolic Pathways ◽  
Phaeodactylum Tricornutum ◽  
Mass Spectrometry Data ◽  
Marine Diatom ◽  
Chemical Mutagenesis ◽  
Carotenoid Content ◽  
Enzymatic Reactions ◽  
Wild Type ◽  
A Genome

Diatoms are a major group of unicellular algae that are rich in lipids and carotenoids. However, sustained research efforts are needed to improve the strain performance for high product yields towards commercialization. In this study, we generated a number of mutants of the model diatom Phaeodactylum tricornutum, a cosmopolitan species that has also been found in Nordic region, using the chemical mutagens ethyl methanesulfonate (EMS) and N-methyl-N′-nitro-N-nitrosoguanidine (NTG). We found that both chlorophyll a and neutral lipids had a significant correlation with carotenoid content and these correlations were better during exponential growth than in the stationary growth phase. Then, we studied P. tricornutum common metabolic pathways and analyzed correlated enzymatic reactions between fucoxanthin synthesis and pigmentation or lipid metabolism through a genome-scale metabolic model. The integration of the computational results with liquid chromatography-mass spectrometry data revealed key compounds underlying the correlative metabolic pathways. Approximately 1000 strains were screened using fluorescence-based high-throughput method and five mutants selected had 33% or higher total carotenoids than the wild type, in which four strains remained stable in the long term and the top mutant exhibited an increase of 69.3% in fucoxanthin content compared to the wild type. The platform described in this study may be applied to the screening of other high performing diatom strains for industrial applications.

scholarly journals Determination of carotenoids in flowers and food supplements by HPLC-DAD

2020 ◽  
Vol 13 (1) ◽  
pp. 6-12
Author(s):  
Petra Pavelková ◽  
Aleš Krmela ◽  
Věra Schulzová
Keyword(s):  
Alkaline Hydrolysis ◽  
High Performance ◽  
Dry Matter ◽  
Food Supplements ◽  
Carotenoid Content ◽  
Tagetes Patula ◽  
Calendula Officinalis ◽  
Limit Of Quantification ◽  
Array Detection

AbstractMarigold flowers (Tagetes patula and Calendula officinalis) were chosen for analysis because they are the most often used source of lutein and its isomer zeaxanthin for the production of food supplements on the Czech market. Direct extraction and extraction with alkaline hydrolysis were compared to detect free or bound carotenoids. For carotenoid separation, C18 and C30 columns were used. A new method for determination of carotenoid content in food supplements in form of capsules has been developed and validated. All matrices were analysed by high-performance liquid chromatography with diode array detection (HPLC-DAD). It has been found that alkaline hydrolysis is required for both Marigold flowers and food supplements to release lutein from ester bonds to fatty acids. In Calendula officinalis lutein in the concentration of 807—1472 mg·kg−1 of dry matter was detected. Tagetes patula has been identified as a better lutein source with the content of 5906—8677 mg·kg−1 of dry matter. It has been found that the content of lutein and zeaxanthin in commercial food supplements (Lutein Complex Premium and Occutein Brillant) is consistent with the declared quantity. Linearity of the HPLC-DAD method ranged from 0.1—20 μg·mL−1 with the limit of quantification (LOQ) of 1.7 mg·kg−1 for lutein in Marigold flowers and 200 mg·kg−1 in food supplements. Repeatability was 2.3 % for lutein in all tested matrices.

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