scholarly journals Time-resolved carotenoid profiling and transcriptomic analysis reveal mechanism of carotenogenesis for astaxanthin synthesis in the oleaginous green alga Chromochloris zofingiensis

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Yu Zhang ◽  
Meicheng Shi ◽  
Xuemei Mao ◽  
Yaping Kou ◽  
Jin Liu

Abstract Background Chromochloris zofingiensis is emerging as an industrially relevant alga given its robust growth for the production of lipids and astaxanthin, a value-added carotenoid with broad applications. Nevertheless, poor understanding of astaxanthin synthesis has limited engineering of this alga for rational improvements. Results To reveal the molecular mechanism underlying astaxanthin accumulation in C. zofingiensis, here we conducted an integrated analysis by combining the time-resolved transcriptomes and carotenoid profiling in response to nitrogen deprivation (ND). A global response was triggered for C. zofingiensis to cope with the ND stress. Albeit the little variation in total carotenoid content, individual carotenoids responded differentially to ND: the primary carotenoids particularly lutein and β-carotene decreased, while the secondary carotenoids increased considerably, with astaxanthin and canthaxanthin being the most increased ones. The carotenogenesis pathways were reconstructed: ND had little effect on the carbon flux to carotenoid precursors, but stimulated astaxanthin biosynthesis while repressing lutein biosynthesis, thereby diverting the carotenoid flux from primary carotenoids to secondary carotenoids particularly astaxanthin. Comparison between C. zofingiensis and Haematococcus pluvialis revealed the distinctive mechanism of astaxanthin synthesis in C. zofingiensis. Furthermore, potential bottlenecks in astaxanthin synthesis were identified and possible engineering strategies were proposed for the alga. Conclusions Collectively, these findings shed light on distinctive mechanism of carotenogenesis for astaxanthin biosynthesis in C. zofingiensis, identify key functional enzymes and regulators with engineering potential and will benefit rational manipulation of this alga for improving nutritional traits.

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 910
Author(s):  
María I. Sáez ◽  
María D. Suárez ◽  
Francisco J. Alarcón ◽  
Tomás F. Martínez

This study evaluates the potential of different algae extracts (Crassiphycus corneus, Cc; Ulva ohnoi, Uo; Arthrospira platensis, Ap; Haematococcus pluvialis, Hp) as additives for the preservation of rainbow trout fillets. The extracts were prepared with different water to ethanol ratios from the four algae species. The highest ferric reducing antioxidant power (FRAP) was observed in Uo extracted in 80% ethanol. Ap aqueous extract also had considerable FRAP activity, in agreement with a high total phenolic content. Radical scavenging activity (DPPH) was higher in Cc 80% ethanol extract, in agreement with a high total carotenoid content. In fact, when the algae aqueous extracts were assayed on the fish fillets, their antioxidant activity exceeded that of ascorbic acid (ASC). All algae extracts delayed microbial growth and lipid oxidation processes in trout fillets throughout the cold storage period compared to controls, and also improved textural parameters, these effects being more evident for Ap and Hp. With respect to the color parameters, the Hp extract prevented the a* values (redness) from decreasing throughout cold storage, a key point when it comes to colored species, not least salmonids. On the other hand, the Ap extract was not as effective as the rest of treatments in avoiding a* and b* decrease throughout the storage period, and thereby the color parameters were impaired. The results obtained, together with the natural origin and the viability for large-scale cultivation, make algae extracts interesting fish preservative agents for the food industry.


2017 ◽  
Vol 47 (3) ◽  
pp. 369-380 ◽  
Author(s):  
Demelash Hailu Mitiku ◽  
Tilahun Abera Teka

Purpose The purpose of this study was to compare the nutrient and antinutrient content of two improved sweet potato varieties released for drought prone areas of eastern Ethiopia. Design/methodology/approach Matured roots of two sweet potato varieties, namely, Berkume and Adu, were collected from Haramaya University, Toni Research Farm, Ethiopia. The sweet potatoes were ground into flour following standard procedure. Thereafter, proximate, dietary minerals and β-carotene were determined by official methods of analysis. The tannin and phytate contents were determined by colorimetric methods. Findings The moisture, protein, fat, fiber, ash, utilizable carbohydrate and gross energy varied from 6.23-6.61 per cent, 2.07-2.76 per cent, 1.25-1.52 per cent, 1.04-1.16 per cent, 3.38- 5.32 per cent, 90.03-91.45 per cent and 382.18-388.07 Kcal/100 g in both the sweet potato varieties. Potassium content (176.17 mg/100 g) was reported to be the highest and registered in Berkume variety, while the lowest mineral content (2.18 mg/100 g) determined was zinc in Adu sweet potato variety. The highest total carotenoid content (3.39mg/100 g) was recorded in Berkume sweet potato variety. The tannin and phytic acid contents ranged from 9.98 to 12.94 mg/100 g and from 0.24 to 0.31 mg/100 g in Berkume and Adu sweet potato varieties, respectively. Originality/value This study showed that the Berkume sweet potato variety has high nutritional potential and less antinutrient contents as compared with the nutritional value of many other roots and tuber crops documented in the FAO database and hence can contribute to reducing malnutrition in resource-poor settings of Ethiopia. Further work needs to be carried out on developing value-added products from Berkume sweet potato variety for its extensive utilization.


2021 ◽  
Vol 7 (4) ◽  
pp. 57-65
Author(s):  
Md. Hafizul Haque Khan ◽  
◽  
Mohammad Mainuddin Molla ◽  
Ashfak Ahmed Sabuz ◽  
Md. Golam Ferdous Chowdhury ◽  
...  

The study explored to find out the possible strategy for the processing of sapota into its value-added shelf-stable products. Therefore, an attempt was made to develop marmalade with different concentrations of orange peel viz. 0 %, 5 %, 10 %, 15 % and 20 % respectively. Sensory evaluation, proximate and nutritional composition was performed on the day of preparation and after storage. Marmalade treated with orange peel and without orange peel was rich source of proximate and nutritional composition. The final TSS of the developed marmalade maintained 65.30±02°B. ß-carotene (12.21±0.01 and 11.93±0.03 µg/100 g), pH (5.05±0.04 and 4.90±0.01), total sugar (21.15±0.04 % and 22.28±0.03 %) and reducing sugar (9.70±0.01 % and 10.15±0.05 %) was superior on the day of storage and after storage in without orange peel treated marmalade (T1). On the day of storage and after storage, the highest total carotenoid and vitamin-C content of the orange peel treated marmalade ranged from 31.92±0.02 to 49.21±0.51 mg/100 g and 23.26±0.02 to 43.39±0.05 mg/100 g, 4.68±0.02 to 5.84±0.03 mg/100 g and 2.36±0.01 to 3.62±0.06 mg/100 g respectively. According to the expert panelist, the highest overall acceptability score was secured by the combination of T2 followed by others in terms of color, aroma, mouth feel and high spreadable capacity. The marketable life of the developed marmalade could be extended 6 months more without any excessive-quality deterioration. This technology could be utilized to fulfill the off-season nutritional requirement and increase the income of the farmers to enhance their productivity. Keywords: Sapota fruit, vitamin-C content, total carotenoid content, ß-carotene content, marketable life, sensory evaluation.


1997 ◽  
Vol 60 (7) ◽  
pp. 853-857 ◽  
Author(s):  
Mª ISABEL MÍNGUEZ-MOSQUERA ◽  
DÁMASO HORNERO-MÉNDEZ

The effect of the industrial processing of peppers for paprika on carotenoids with provitamin A activity has been investigated. The processing consists of two principal steps: drying and milling. The milling step appears to be the more destructive, leading to a loss of 42.7 to 55.2% in the total carotenoid content and 65.2 to 81.4% in that of provitamin A, depending on the variety of the fruit. However, adding seeds from the peppers during this step dilutes the paprika, reducing the carotenoid losses due to the process itself to around 20%. The drying step is less destructive, but its final effect depends markedly on the degree of ripeness of the fruit and the variety of peppers used. Carotenoids with provitamin A value present in Capsicum annuum are β-carotene, β-cryptoxanthin, and cryptocapsin, which are degraded during the process by 67.3 to 82.2%, 59.2 to 78.9%, and 54.1 to 58.1 % respectively, resulting in a loss of provitamin A activity of ca. 65.2 to 81.4%.


Author(s):  
A. K. Veligodska ◽  
O. V. Fedotov ◽  
A. S. Petreeva

<p>The influence of certain nitrogen compounds - components of glucose-peptone medium (GPM) on the accumulation of carotenoids by some strains was investigated by surface cultivating basidiomycetes. The total carotenoid content was set in acetone extracts of mycological material spectrophotometrically and calculated using the Vetshteyn formula.</p> <p>As the nitrogen-containing components used GPM with 9 compounds, such as peptone, DL-valine, L-asparagine, DL-serine, DL-tyrosine, L-proline, L-alanine, urea, NaNO<sub>3</sub>. The effect on the accumulation of specific compounds both in the mycelium and in the culture fluid of carotenoids by culturing certain strains of Basidiomycetes was identified.</p> <p>Adding to standard glucose-peptone medium peptone at 5 g/l causes an increase of carotenoid accumulation by strain <em>L. sulphureus</em> Ls-08, and in a concentration of 4 g/l by strains of <em>F. hepatica </em>Fh-18 and <em>F. fomentarius</em> Ff-1201.</p> <p>In order to increase the accumulation of carotenoids in the mycelium  we suggested to make a standard glucose-peptone medium with proline or valine for cultivating of <em>L. sulphureus</em> Ls- 08 strain; alanine for <em>F. fomentarius</em> Ff-1201 strain; proline, asparagine and serine - for strain Fh-18 of <em>F. hepatica</em>. The results can be implemented in further optimization of the composition of the nutrient medium for culturing strains of Basidiomycetes wich producing carotenoids.</p> <p><em>Keywords: nitrogen-containing substances, Basidiomycetes, mycelium</em><em>,</em><em> culture filtrate, carotenoids</em></p>


2018 ◽  
Author(s):  
Younghwan Cha ◽  
Jung-In Lee ◽  
Panpan Dong ◽  
Xiahui Zhang ◽  
Min-Kyu Song

A novel strategy for the oxidation of Mg-based intermetallic compounds using CO<sub>2</sub> as an oxidizing agent was realized via simple thermal treatment, called ‘CO2-thermic Oxidation Process (CO-OP)’. Furthermore, as a value-added application, electrochemical properties of one of the reaction products (carbon-coated macroporous silicon) was evaluated. Considering the facile tunability of the chemical/physical properties of Mg-based intermetallics, we believe that this route can provide a simple and versatile platform for functional energy materials synthesis as well as CO<sub>2</sub> chemical utilization in an environment-friendly and sustainable way.


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