scholarly journals Potential of New Isolates of Dunaliella salina for Natural β-Carotene Production

2018 ◽  
Author(s):  
Yanan Xu ◽  
Iskander M. Ibrahim ◽  
Chiziezi I. Wosu ◽  
Ami Ben-Amotz ◽  
Patricia J. Harvey
Keyword(s):  
Dunaliella Salina ◽  
Biochemical Characterization ◽  
Light Stress ◽  
Beta Carotene ◽  
High Rate ◽  
Cellular Functions ◽  
Genetic Classification ◽  
Cellular Content ◽  
Grouping Strategy ◽  
Positive Correlations

The halotolerant microalga Dunaliella salina has been widely studied for natural β-carotene production. This work shows biochemical characterization of three newly isolated Dunaliella salina strains DF15, DF17 and DF40 compared with D. salina CCAP 19/30 (confirmed to be D. tertiolecta) and D. salina UTEX 2538 (also known as D. bardawil). Although all three new strains have been genetically characterized as Dunaliella salina strains, their ability to accumulate carotenoids and their capacity for photoprotection against high light stress are different. DF15 and UTEX 2538 reveal great potential for producing large amount of β-carotene and maintained a high rate of photosynthesis under light of high intensity; however, DF17, DF40 and CCAP 19/30 showed increasing photoinhibition with increasing light intensity, and reduced contents of carotenoids, in particular b-carotene, suggesting that the capacity of photoprotection is dependent on the cellular content of carotenoids, in particular β-carotene. Strong positive correlations were found between the cellular content of each of all-trans β-carotene, 9-cis β-carotene, all-trans α-carotene and zeaxanthin but not lutein in the D. salina strains. Lutein was strongly correlated with respiration in photosynthetic cells and strongly related to photosynthesis, chlorophyll and respiration, suggesting an important and not hitherto identified role for lutein in co-ordinated control of the cellular functions of photosynthesis and respiration in response to changes in light conditions, which is broadly conserved in Dunaliella strains. Statistical analysis based on biochemical data revealed a different grouping strategy from the genetic classification of the strains. The significance of these data for strain selection for commercial carotenoid production is discussed.

The effect of audible sound frequency on the growth and beta-carotene production of Dunaliella salina

2021 ◽  
Vol 141 ◽  
pp. 373-382
Author(s):  
Arezoo Keramati ◽  
Farshid Pajoum Shariati ◽  
Omid Tavakoli ◽  
Zahra Akbari ◽  
Mina Rezaei
Keyword(s):  
Dunaliella Salina ◽  
Beta Carotene ◽  
Sound Frequency ◽  
Audible Sound

scholarly journals Oxygen radicals, nitric oxide, and peroxynitrite: Redox pathways in molecular medicine

2018 ◽  
Vol 115 (23) ◽  
pp. 5839-5848 ◽  
Author(s):  
Rafael Radi
Keyword(s):  
Nitric Oxide ◽  
Free Radical ◽  
Mammalian Cells ◽  
Oxygen Radicals ◽  
Biochemical Characterization ◽  
Cell Function ◽  
Molecular Medicine ◽  
Antioxidant Systems ◽  
Cellular Functions ◽  
Cell Degeneration

Oxygen-derived free radicals and related oxidants are ubiquitous and short-lived intermediates formed in aerobic organisms throughout life. These reactive species participate in redox reactions leading to oxidative modifications in biomolecules, among which proteins and lipids are preferential targets. Despite a broad array of enzymatic and nonenzymatic antioxidant systems in mammalian cells and microbes, excess oxidant formation causes accumulation of new products that may compromise cell function and structure leading to cell degeneration and death. Oxidative events are associated with pathological conditions and the process of normal aging. Notably, physiological levels of oxidants also modulate cellular functions via homeostatic redox-sensitive cell signaling cascades. On the other hand, nitric oxide (•NO), a free radical and weak oxidant, represents a master physiological regulator via reversible interactions with heme proteins. The bioavailability and actions of •NO are modulated by its fast reaction with superoxide radical (O2•−), which yields an unusual and reactive peroxide, peroxynitrite, representing the merging of the oxygen radicals and •NO pathways. In this Inaugural Article, I summarize early and remarkable developments in free radical biochemistry and the later evolution of the field toward molecular medicine; this transition includes our contributions disclosing the relationship of •NO with redox intermediates and metabolism. The biochemical characterization, identification, and quantitation of peroxynitrite and its role in disease processes have concentrated much of our attention. Being a mediator of protein oxidation and nitration, lipid peroxidation, mitochondrial dysfunction, and cell death, peroxynitrite represents both a pathophysiologically relevant endogenous cytotoxin and a cytotoxic effector against invading pathogens.

scholarly journals Stereoisomers of Colourless Carotenoids from the Marine Microalga Dunaliella salina

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1880 ◽  
Author(s):  
Laura Mazzucchi ◽  
Yanan Xu ◽  
Patricia Harvey
Keyword(s):  
Dunaliella Salina ◽  
Light Stress ◽  
Red Light ◽  
Chemical Properties ◽  
Phytoene Desaturase ◽  
Cell Factory ◽  
Geranylgeranyl Diphosphate ◽  
Diverse Range ◽  
Marine Microalga ◽  
Β Carotene

Carotenoids comprise a diverse range of naturally occurring stereoisomers, which differ in their physico-chemical properties. Their biosynthesis begins with phytoene, which is a rarity among carotenoids because it is colourless. Phytoene is sought after as a skin protectant against harmful UV range B (290–320 nm) and C (100–290 nm) light, and as a natural skin-whitening agent and is synthesized from geranylgeranyl diphosphate. Geranylgeranyl diphosphate is catalysed by phytoene synthase and phytoene desaturase to phytoene and phytofluene, respectively. The subsequent steps involve desaturation, isomerisation and cyclisation reactions to form α- and β-carotene stereoisomers, via all-trans lycopene. The marine microalga Dunaliella salina is the richest source of β-carotene, but it can accumulate phytoene and phytofluene as well. In the present study, different analytical tools including High-Performance Liquid Chromatography (HPLC), Ultra-Performance Convergence Chromatography (UPC2-MS) and Nuclear Magnetic Resonance (NMR) were used to characterize and quantify the phytoene isomeric configurations in D. salina in order to explore both the feasibility of D. salina as a cell factory for phytoene production and to gain new insight into the carotenoid synthesis pathway in D. salina. D. salina, similar to tomato, produced predominantly 15-cis phytoene isomer (>98%) and a trace amount of all-trans phytoene (<2%). High light stress, red light stress, or use of a phytoene desaturase inhibitor or a mitotic disrupter herbicide led to the accumulation of 15-cis phytoene but not all-trans phytoene. 9-cis phytoene was not detected in any of the extracts of D. salina biomass. Our main findings suggest that 15-cis phytoene is the most abundant isomer in D. salina and that it is subject to a series of isomerisation and desaturation reactions to form all-trans and 9-cis β-carotene.

scholarly journals High Light Stress Regimen on Dunaliella Salina Strains For Carotenoids Induction

2016 ◽  
Vol 3 (4) ◽  
Author(s):  
Anh Nguyen ◽  
Dat Tran ◽  
Minh Ho ◽  
Clifford Louime ◽  
Hanh Tran ◽  
...  
Keyword(s):  
Dunaliella Salina ◽  
Light Stress ◽  
High Light ◽  
High Light Stress

Identification of microRNAs response to high light and salinity that involved in beta-carotene accumulation in microalga Dunaliella salina

2020 ◽  
Vol 48 ◽  
pp. 101925 ◽  
Author(s):  
Sulin Lou ◽  
Xiulan Zhu ◽  
Zhiyong Zeng ◽  
Huina Wang ◽  
Bin Jia ◽  
...  
Keyword(s):  
Dunaliella Salina ◽  
Beta Carotene ◽  
High Light

scholarly journals Effects of phosphorus on the growth and chlorophyll fluorescence of a Dunaliella salina strain isolated from saline soil under nitrate limitation

2016 ◽  
Vol 89 (2) ◽  
Author(s):  
Tassnapa Wongsnansilp ◽  
Niran Juntawong ◽  
Zhe Wu
Keyword(s):  
Dunaliella Salina ◽  
Beta Carotene ◽  
Phosphate Concentration ◽  
Carotene Content ◽  
Ps Ii ◽  
Algae Growth ◽  
Kinetics Of ◽  
Late Growth ◽  
High Phosphate ◽  
Northeastern Thailand

An isolated <em>Dunaliella salina</em> (<em>D. salina</em>) KU XI from saline soils in northeastern Thailand was cultured in f/2 medium in column photobioreactor. The variations of the growth, chlorophyll and beta-carotene content and the maximum quantum yield of PS II photochemistry (F<sub>v</sub>/F<sub>m</sub>) under different NaH<sub>2</sub>PO<sub>4</sub> concentrations were studied. Based on the results, the growth kinetics of <em>D. salina</em> KU XI was established, which could simulate the algae growth rate under different phosphate concentrations and temperatures. The phosphorus could significantly affect the growth and pigments accumulations of this isolated strain. Increasing NaH<sub>2</sub>PO<sub>4</sub> concentration improved the biomass, the total chlorophyll and beta-carotene content, retarded the decrease of F<sub>v</sub>/F<sub>m</sub> value. The optimal phosphate concentration for the growth of <em>D. salina</em> KU XI was above 72.6 μM. The maximum biomass and beta-carotene were 0.24 g L<sup>-1</sup> and 17.4 mg L<sup>-1</sup> respectively when NaH<sub>2</sub>PO<sub>4</sub> was 290.4 μM. The algae growth was restrained by phosphate or nitrate when NaH<sub>2</sub>PO<sub>4</sub> below 12.1 μM or above 72.6 μM. It indicated that properly supplementing nitrate in the late growth stage with high phosphate concentration was favored for enhancing the growth and biomass production.

scholarly journals Facebook Users’ Interactions, Organic Reach, and Engagement in a Smoking Cessation Intervention: Content Analysis

10.2196/27853 ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. e27853
Author(s):  
Dávid Pócs ◽  
Otília Adamovits ◽  
Jezdancher Watti ◽  
Róbert Kovács ◽  
Oguz Kelemen
Keyword(s):  
Public Health ◽  
Smoking Cessation ◽  
Correlation Method ◽  
Significant Negative Correlation ◽  
Health Interventions ◽  
High Rate ◽  
Specific Interactions ◽  
Public Health Interventions ◽  
Positive Correlations ◽  
The Given

Background Facebook can be a suitable platform for public health interventions. Facebook users can express their reaction to the given social media content in many ways using interaction buttons. The analysis of these interactions can be advantageous in increasing reach and engagement of public health interventions. Objective This research aimed at understanding how Facebook users’ interactions correlate with organic reach and engagement regarding the same smoking cessation support contents. Methods The study population consisted of Facebook users who were reached by a public smoking cessation support page without advertising. We included 1025 nonpaid Facebook posts (N=1025) which used smoking cessation strategies based on a motivational interviewing counseling style. The following data were collected from the “Post Details”: the number of people who saw the given nonpaid content (organic reach) which consisted of fan and nonfan reach according to previous “page like” activity; each rate of “engagement indicators” (such as the symbols of “like,” “love,” “haha,” “wow,” “sad,” “angry”; or other interactions: “shares,” “comments,” “clicks”); and the rate of negative Facebook interactions (eg, “post hides” or “unlike of page”). Overall, these data were analyzed with the Spearman correlation method. Results Surprisingly, we found a significant negative correlation between organic reach and the “like” reaction (rs=–0.418; P<.001). The strongest significant positive correlations of organic reach were observed with the “haha” reaction (rs=0.396; P<.001), comments (rs=0.368; P<.001), and the “love” reaction (rs=0.264; P<.001). Furthermore, nonfan reach correlated positively with “shares” (rs=0.388; P<.001) and clicks (rs=0.135; P<.001), while fan reach correlated positively with the “haha” reaction (rs=0.457; P<.001), comments (rs=0.393; P<.001), and the “love” reaction (rs=0.310; P<.001). Contrary to expectations, the “like” reaction was sharply separated by significant negative correlations from “wow” (rs=–0.077; P=.013), “sad” (rs=–0.120; P<.001), “angry” reactions (rs=–0.136; P<.001), and comments (rs=–0.130; P<.001). Additionally, a high rate of negative Facebook interactions was significantly associated with “wow” (rs=0.076; P=.016) and “sad” reactions (rs=0.091; P=.003). Conclusions This study has shown that it is possible to hypothesize a disadvantage of the “like” reaction and advantages of other interactions (eg, the “haha” reaction or “comments”) in content algorithmic ranking on Facebook. In addition, the correlational analysis revealed a need of a further categorization to fan-specific interactions (eg, “haha” or “love” reactions) and nonfan-specific interactions (eg, “shares” and “clicks”). Regarding the direction of the correlations, these findings suggest that some interactions (eg, negative Facebook interactions, “wow,” “sad,” and “angry” reactions) may decrease the engagement, while other interactions (“like,” “love,” “haha” reactions, “shares,” and “clicks”) may increase the engagement during Facebook-based smoking cessation interventions. This hypothesis-generating research offers an important insight into the relationship between organic reach, engagement, and Facebook users’ interactions for public health professionals who design Facebook-based interventions.

scholarly journals Boosting of Antioxidants and Alkaloids in Catharanthus roseus Suspension Cultures Using Silver Nanoparticles with Expression of CrMPK3 and STR Genes

Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2202
Author(s):  
Ahmed Fouad ◽  
Adel E. Hegazy ◽  
Ehab Azab ◽  
Ebtihal Khojah ◽  
Tarek Kapiel
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Catharanthus Roseus ◽  
Crop Yields ◽  
Regulatory Gene ◽  
Suspension Cultures ◽  
Mitogen Activated Protein Kinase ◽  
Cellular Functions ◽  
Mitogen Activated Protein ◽  
Positive Correlations

Global agricultural systems are under unprecedented pressures due to climate change. Advanced nano-engineering can help increase crop yields while ensuring sustainability. Nanotechnology improves agricultural productivity by boosting input efficiency and reducing waste. Alkaloids as one of the numerous secondary metabolites that serve variety of cellular functions essential for physiological processes. This study tests the competence of silver nanoparticles (AgNPs) in boosting alkaloids accumulation in Catharanthus roseus suspension cultures in relation to the expression of C. roseus Mitogen Activated Protein Kinase 3 (CrMPK3) and Strictosidine Synthase (STR) genes. Five concentrations (5, 10, 15, 20 and 25 mg·L−1) of AgNPs were utilized in addition to deionized water as control. Results reflected binary positive correlations among AgNPs concentration, oxidative stress indicated with increase in hydrogen peroxide and malondialdehyde contents, activities of ascorbate peroxidase and superoxide dismutase, expression of the regulatory gene CrMPK3 and the alkaloid biosynthetic gene STR as well as alkaloids accumulation. These correlations add to the growing evidence that AgNPs can trigger the accumulation of alkaloids in plant cells through a signaling pathway that involves hydrogen peroxide and MAPKs, leading to up-regulation of the biosynthetic genes, including STR gene.

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