Influence of Light Conditions on Microalgae Growth and Content of Lipids, Carotenoids, and Fatty Acid Composition

Microalgae are a valuable natural resource for a variety of value-added products. The growth of microalgae is determined by the impact of many factors, but, from the point of view of the implementation of autotrophic growth, light is of primary importance. This work presents an overview of the influence of light conditions on the growth of microalgae, the content of lipids, carotenoids, and the composition of fatty acids in their biomass, taking into account parameters such as the intensity, duration of lighting, and use of rays of different spectral composition. The optimal light intensity for the growth of microalgae lies in the following range: 26−400 µmol photons m−2 s−1. An increase in light intensity leads to an activation of lipid synthesis. For maximum lipid productivity, various microalgae species and strains need lighting of different intensities: from 60 to 700 µmol photons m−2 s−1. Strong light preferentially increases the triacylglyceride content. The intensity of lighting has a regulating effect on the synthesis of fatty acids, carotenoids, including β-carotene, lutein and astaxanthin. In intense lighting conditions, saturated fatty acids usually accumulate, as well as monounsaturated ones, and the number of polyunsaturated fatty acids decreases. Red as well as blue LED lighting improves the biomass productivity of microalgae of various taxonomic groups. Changing the duration of the photoperiod, the use of pulsed light can stimulate microalgae growth, the production of lipids, and carotenoids. The simultaneous use of light and other stresses contributes to a stronger effect on the productivity of algae.

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Differential Deleterious Impact of Highly Saturated Versus Monounsaturated Fat Intake on Vascular Function, Structure, and Mechanics in Mice

Nutrients ◽

10.3390/nu13031003 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1003

Author(s):

Elena Vega-Martín ◽

Marta Gil-Ortega ◽

Raquel González-Blázquez ◽

Sara Benedito ◽

Jesús Fernández-Felipe ◽

...

Keyword(s):

Fatty Acids ◽

Arterial Stiffness ◽

Thoracic Aorta ◽

Vascular Function ◽

Saturated Fatty Acids ◽

Vascular Wall ◽

Monounsaturated Fatty Acids ◽

Mesenteric Arteries ◽

Monounsaturated Fat ◽

The Impact

Vegetable oils such as palm oil (enriched in saturated fatty acids, SFA) and high-oleic-acid sunflower oil (HOSO, containing mainly monounsaturated fatty acids, MUFA) have emerged as the most common replacements for trans-fats in the food industry. The aim of this study is to analyze the impact of SFA and MUFA-enriched high-fat (HF) diets on endothelial function, vascular remodeling, and arterial stiffness compared to commercial HF diets. Five-week-old male C57BL6J mice were fed a standard (SD), a HF diet enriched with SFA (saturated oil-enriched Food, SOLF), a HF diet enriched with MUFA (unsaturated oil-enriched Food, UOLF), or a commercial HF diet for 8 weeks. Vascular function was analyzed in the thoracic aorta. Structural and mechanical parameters were assessed in mesenteric arteries by pressure myography. SOLF, UOLF, and HF diet reduced contractile responses to phenylephrine and induced endothelial dysfunction in the thoracic aorta. A significant increase in the β-index, and thus in arterial stiffness, was also detected in mesenteric arteries from the three HF groups, due to enhanced deposition of collagen in the vascular wall. SOLF also induced hypotrophic inward remodeling. In conclusion, these data demonstrate a deleterious effect of HF feeding on obesity-related vascular alterations that is exacerbated by SFA.

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Dairy Fat Consumption and the Risk of Metabolic Syndrome: An Examination of the Saturated Fatty Acids in Dairy

Nutrients ◽

10.3390/nu11092200 ◽

2019 ◽

Vol 11 (9) ◽

pp. 2200 ◽

Cited By ~ 8

Author(s):

Unger ◽

Torres-Gonzalez ◽

Kraft

Keyword(s):

Metabolic Syndrome ◽

Fatty Acids ◽

Disease Risk ◽

Saturated Fatty Acids ◽

Saturated Fat ◽

Dietary Guidelines ◽

The Body ◽

Specific Chemical ◽

Dairy Consumption ◽

The Impact

Lifestyle is a key modifiable risk factor involved in the manifestation of metabolic syndrome and, in particular, diet plays a pivotal role in its prevention and development. Current dietary guidelines discourage the consumption of saturated fat and dietary sources rich in saturated fat, such as dairy products, despite data suggesting that full-fat dairy consumption is protective against metabolic syndrome. This narrative review assessed the recent epidemiological and clinical research that examined the consumption of dairy-derived saturated fatty acids (SFA) on metabolic syndrome risk. In addition, this review evaluated studies of individual SFA to gain insight into the potential mechanisms at play with intake of a diet enriched with these dairy-derived fatty acids. This work underscores that SFA are a heterogenous class of fatty acids that can differ considerably in their biological activity within the body depending on their length and specific chemical structure. In summary, previous work on the impact of dairy-derived SFA consumption on disease risk suggests that there is currently insufficient evidence to support current dietary guidelines which consolidate all dietary SFA into a single group of nutrients whose consumption should be reduced, regardless of dietary source, food matrix, and composition.

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Chemical Composition of Cynara cardunculus L. var. altilis Bracts Cultivated in Central Greece: The Impact of Harvesting Time

Agronomy ◽

10.3390/agronomy10121976 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1976

Author(s):

Filipa Mandim ◽

Spyridon A. Petropoulos ◽

Kyriakos D. Giannoulis ◽

Celestino Santos-Buelga ◽

Isabel C. F. R. Ferreira ◽

...

Keyword(s):

Fatty Acids ◽

Chemical Composition ◽

Organic Acids ◽

Saturated Fatty Acids ◽

Dry Weight ◽

Monounsaturated Fatty Acids ◽

Maturity Stage ◽

Harvesting Time ◽

Late Maturity ◽

The Impact

The present study evaluated the effect of maturity stage on the chemical composition of cardoon bracts. Plant material was collected in Greece at eight different maturation stages (C1–C8) and the chemical composition was analyzed in regard to lipidic fraction and the content in fatty acids, tocopherols, organic acids, and free sugars. Samples of late maturity (C6–C8) revealed the lowest lipidic content, while a total of 29 fatty acids was identified in all the samples, with palmitic, stearic, oleic, and eicosatrienoic acids present in the highest levels depending on harvesting time. Immature (C1) and mature (C8) bracts were more abundant in saturated fatty acids (SFA) than bracts of medium-to-late maturity (C5, C6), where the monounsaturated fatty acids (MUFA) were the prevalent class. The α- and γ-tocopherols were the only identified isoforms of vitamin E, while the highest content was observed in sample C8 (199 µg/100 g dry weight (dw). The detected organic acids were oxalic, quinic, malic, citric, and fumaric acids, while fructose, glucose, sucrose, trehalose, and raffinose were the main detected sugars. The results of the present study allowed us to reveal the effect of maturity stage on cardoon bracts chemical composition and further valorize this byproduct by improving its bioactive compounds content.

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Nutritional quality, safety and sensory properties of smoked tench (Tinca tinca) pâté from Trasimeno Lake, Italy

Italian Journal of Food Safety ◽

10.4081/ijfs.2019.8130 ◽

2019 ◽

Vol 8 (3) ◽

Cited By ~ 2

Author(s):

Raffaella Branciari ◽

Rossana Roila ◽

Andrea Valiani ◽

David Ranucci ◽

Roberta Ortenzi ◽

...

Keyword(s):

Fatty Acids ◽

Olive Oil ◽

Saturated Fatty Acids ◽

Challenge Test ◽

Value Added ◽

Monounsaturated Fatty Acids ◽

Sensory Properties ◽

Sensory Profile ◽

Tinca Tinca ◽

Tench Tinca Tinca

The present study evaluated the safety, nutritional and sensory properties of fish pâtés made from smoked tench (Tinca tinca) pulp. Two formulations of tench pâté were produced, one of which included olive oil and the other contained mascarpone cheese. The prepared pâté jars were thermally treated according to the method applied in the canning industry. The inactivation of Clostridium botulinum during thermal treatment was determined through a challenge test study, demonstrating the complete depletion of targeted bacteria. Tench pâtés showed high nutritional properties, especially the formulation with olive oil, which was characterised by lower contents of cholesterol and saturated fatty acids and a high level of monounsaturated fatty acids. The two experimental formulations possessed a specific sensory profile, due to the ingredients incorporated into the products. Consumers’ evaluation established differences in the acceptance of the two products: the formulation with added olive oil was more appreciated by consumers, who displayed a higher purchase intent for this product. The study suggests that minced smoked tench is not only a promising ingredient for pâté production but that it also represents a value-added product able to contribute to freshwater food consumption.

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Porcine Hepatic Response to Fumonisin B1 in a Short Exposure Period: Fatty Acid Profile and Clinical Investigations

Toxins ◽

10.3390/toxins11110655 ◽

2019 ◽

Vol 11 (11) ◽

pp. 655 ◽

Cited By ~ 2

Author(s):

Omeralfaroug Ali ◽

Judit Szabó-Fodor ◽

Hedvig Fébel ◽

Miklós Mézes ◽

Krisztián Balogh ◽

...

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Saturated Fatty Acids ◽

Fumonisin B1 ◽

Exposure Period ◽

Short Exposure ◽

Lung Edema ◽

Fungal Culture ◽

Arachidonic Acids ◽

The Impact

Scarce studies have investigated the impact of fumonisin B1 (FB1) on the hepatic tissue fatty acid (FA) profile, and no study is available on piglets. A 10-day in vivo experiment was performed on seven piglets/group: control and FB1-fed animals (diet was contaminated with fungal culture: 20 mg FB1/kg diet). Independent sample t-test was carried out at p < 0.05 as the significance level. Neither growth, nor feed efficiency, was affected. The hepatic phospholipid (PL) fatty acids (FAs) were more susceptible for FB1, while triglyceride (TG) was less responsive. The impact of FB1 on hepatic PL polyunsaturated fatty acids (PUFAs) was more pronounced than on saturated fatty acids. Among all PUFAs, predominant ones in response were docosapentaenoicacid (DPA) (↓), docosahexaenoic DHA (↓) and arachidonic acids (↑). This led to a higher omega-6:omega-3 ratio, whereas a similar finding was noted in TGs. Neither total saturation (SFA) nor total monousaturation (MUFA) were affected by the FB1 administration. The liver showed an increase in malondialdehyde, as well as antioxidant capacity (reduced glutathione and glutathione peroxidase). The plasma enzymatic assessment revealed an increase in alkaline phosphatase (ALP), while alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH), and gamma-glutamyltransferase (GGT) were not influenced. The microscopic sections provided evidence of vacuolar degeneration of the hepatocytes’ cytoplasm, but it was not severe. Furthermore, the lung edema was developed, while the kidney was not affected. In conclusion, regarding FB1-mediated hepatotoxicity in piglets, the potential effect of slight hepatotoxicity did not compromise growth performance, at least at the dose and exposure period applied.

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Fatty acid and phytosterol contents of some Romanian wild and cultivated berry pomaces

Chemical Papers ◽

10.2478/s11696-012-0156-0 ◽

2012 ◽

Vol 66 (10) ◽

Cited By ~ 17

Author(s):

Francisc Dulf ◽

Sanda Andrei ◽

Andrea Bunea ◽

Carmen Socaciu

Keyword(s):

Fatty Acids ◽

Saturated Fatty Acids ◽

Value Added ◽

Rubus Idaeus ◽

Sterol Esters ◽

Aronia Melanocarpa ◽

Waste Oils ◽

Black Chokeberry ◽

Total Oil ◽

Layer Chromatography

AbstractThe total oil content and composition of fatty acids and phytosterols of five Transylvanian (Romania) pomaces of wild and cultivated blueberries (Vaccinium myrtillus), wild cowberry (Vaccinium vitis-idaea) and raspberry (Rubus idaeus), and cultivated black chokeberry (Aronia melanocarpa), were determined by capillary gas chromatography. Out of the five pomace oils, the percentages of polyunsaturated fatty acids (PUFAs) ranged from 37 % to 69 %. The lipid classes analysed (PLs — polar lipids, TGs — triacylglycerols, SEs — sterol esters) were separated and identified using thin-layer chromatography. TGs showed the highest PUFAs content (ranging from 41.9 % to 72.5 %) and PUFAs/SFAs (saturated fatty acids) ratios (in the range of 5.8–33.1 %). In the case of PL and SE fractions, the levels of SFA were significantly higher than in TGs. The total amount of sterols was in the range of 101.6–168.2 mg per 100 g of lipids of the pomaces analysed. The predominant phytosterols were β-sitosterol, stigmastanol + isofucosterol, and campesterol. The results indicated that the investigated pomace oils, due to their good balance between n-6 and n-3 fatty acids (except for chokeberry) and high β-sitosterol content, could be excellent sources of PUFAs and phytosterols, thus suggesting potential value-added utilisation of berry waste oils for preparing functional foods or food supplements.

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Chemical Composition of Cynara Cardunculus L. var. altilis Heads: The Impact of Harvesting Time

Agronomy ◽

10.3390/agronomy10081088 ◽

2020 ◽

Vol 10 (8) ◽

pp. 1088 ◽

Cited By ~ 1

Author(s):

Filipa Mandim ◽

Spyridon A. Petropoulos ◽

Ângela Fernandes ◽

Celestino Santos-Buelga ◽

Isabel C. F. R. Ferreira ◽

...

Keyword(s):

Fatty Acids ◽

Chemical Composition ◽

Organic Acids ◽

Saturated Fatty Acids ◽

Industrial Applications ◽

Added Value ◽

Maturation Stage ◽

Literature Study ◽

Harvesting Time ◽

The Impact

Cardoon is a multi-purpose crop with several industrial applications, while the heads (capitula) are edible and commonly used in various dishes of the Mediterranean diet. Several reports in the literature study the chemical composition of the various plants parts (leaves, flower stalks, bracts, seeds) aiming to industrial applications of crop bio-waste, whereas for the heads, most of the studies are limited to the chemical composition and bioactive properties at the edible stage. In the present study, cardoon heads were collected at six different maturation stages and their chemical composition was evaluated in order to determine the effect of harvesting stage and examine the potential of alternative uses in the food and nutraceutical industries. Lipidic fraction and the content in fatty acids, tocopherols, organic acids, and free sugars were determined. Lipidic content decreases with the maturation process, while 22 fatty acids were detected in total, with palmitic, oleic, and linoleic acids being those with the highest abundance depending on harvesting time. In particular, immature heads have a higher abundance in saturated fatty acids (SFA), whereas the samples of mature heads were the richest in monounsaturated fatty acids (MUFA). The α-tocopherol was the only isoform detected being present in higher amounts in sample Car B (619 µg/100 g dw). Oxalic, quinic, malic, citric and fumaric acids were the detected organic acids, and the higher content was observed in sample Car E (15.7 g/100 g dw). The detected sugars were fructose, glucose, sucrose, trehalose and raffinose, while the highest content (7.4 g/100 g dw) was recorded in sample Car C. In conclusion, the maturation stage of cardoon heads influences their chemical composition and harvesting time could be a useful means to increase the quality and the added value of the final product by introducing this material in the food and nutraceutical industries.

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Switching LPS to LED Streetlight May Dramatically Reduce Activity and Foraging of Bats

Diversity ◽

10.3390/d12040165 ◽

2020 ◽

Vol 12 (4) ◽

pp. 165 ◽

Cited By ~ 2

Author(s):

Christian Kerbiriou ◽

Kévin Barré ◽

Léa Mariton ◽

Julie Pauwels ◽

Georges Zissis ◽

...

Keyword(s):

Light Intensity ◽

New Technologies ◽

Spectral Composition ◽

Developed Countries ◽

Interactive Effects ◽

Street Lighting ◽

Bat Activity ◽

Reduce Activity ◽

The Uk ◽

The Impact

Artificial light at night is considered a major threat to biodiversity, especially for nocturnal species, as it reduces habitat availability, quality, and functionality. Since the recent evolution in light technologies in improving luminous efficacy, developed countries are experiencing a renewal of their lighting equipment that reaches its end-of-life, from conventional lighting technologies to light emitting diodes (LEDs). Despite potential cascading impacts of such a shift on nocturnal fauna, few studies have so far dealt with the impact of the renewal of street lighting by new technologies. Specifically, only one study, by Rowse et al.2016, examined the effects of switching from widely used low pressure sodium (LPS) lamps to LEDs, using bats as biological models. This study was based on a before-after-control-impact paired design (BACIP) at 12 pairs in the UK, each including one control and one experimental streetlight. If Rowse et al. 2016 showed no effect of switching to LEDs streetlights on bat activity, the effects of respective changes in light intensity and spectrum were not disentangled when testing switch effects. Here, we conduct a retrospective analysis of their data to include these covariates in statistical models with the aim of disentangling the relative effects of these light characteristics. Our re-analysis clearly indicates that the switches in spectrum and in intensity with replacement of LPS with LED lamps have significant additive and interactive effects, on bat activity. We also show that bat activity and buzz ratio decrease with increasing LED intensity while an opposite effect is observed with LPS lamps. Hence, the loss or the gain in bat activity when lamp types, i.e., spectrum, are switched strongly depends on the initial and new lamp intensities. Our results stress the need to consider simultaneously the effects of changes in the different lights characteristics when street lighting changes. Because switches from LPS to LED lamps can lead to an increase in light intensity, such technological changes may involve a reduction of bat activity in numerous cases, especially at high LED intensities. Since we are currently at an important crossroad in lighting management, we recommend to limit LED intensity and improve its spectral composition toward warmer colors to limit potential deleterious impacts on bat activity.

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Docosahexaenoic and Eicosapentaenoic Acids Prevent Altered-Muc2 Secretion Induced by Palmitic Acid by Alleviating Endoplasmic Reticulum Stress in LS174T Goblet Cells

Nutrients ◽

10.3390/nu11092179 ◽

2019 ◽

Vol 11 (9) ◽

pp. 2179

Author(s):

Quentin Escoula ◽

Sandrine Bellenger ◽

Michel Narce ◽

Jérôme Bellenger

Keyword(s):

Fatty Acids ◽

Endoplasmic Reticulum ◽

Palmitic Acid ◽

Er Stress ◽

Unsaturated Fatty Acids ◽

Saturated Fatty Acids ◽

Goblet Cells ◽

The Impact

Diets high in saturated fatty acids (FA) represent a risk factor for the development of obesity and associated metabolic disorders, partly through their impact on the epithelial cell barrier integrity. We hypothesized that unsaturated FA could alleviate saturated FA-induced endoplasmic reticulum (ER) stress occurring in intestinal secretory goblet cells, and consequently the reduced synthesis and secretion of mucins that form the protective mucus barrier. To investigate this hypothesis, we treated well-differentiated human colonic LS174T goblet cells with palmitic acid (PAL)—the most commonly used inducer of lipotoxicity in in vitro systems—or n-9, n-6, or n-3 unsaturated fatty acids alone or in co-treatment with PAL, and measured the impact of such treatments on ER stress and Muc2 production. Our results showed that only eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids protect goblet cells against ER stress-mediated altered Muc2 secretion induced by PAL, whereas neither linolenic acid nor n-9 and n-6 FA are able to provide such protection. We conclude that EPA and DHA could represent potential therapeutic nutrients against the detrimental lipotoxicity of saturated fatty acids, associated with type 2 diabetes and obesity or inflammatory bowel disease. These in vitro data remain to be explored in vivo in a context of dietary obesity.

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Cultivating Microalgae in Desert Conditions: Evaluation of the Effect of Light-Temperature Summer Conditions on the Growth and Metabolism of Nannochloropsis QU130

Applied Sciences ◽

10.3390/app11093799 ◽

2021 ◽

Vol 11 (9) ◽

pp. 3799

Author(s):

Hareb Al Jabri ◽

Aumaya Taleb ◽

Raphaelle Touchard ◽

Iman Saadaoui ◽

Vincent Goetz ◽

...

Keyword(s):

Light Intensity ◽

Large Scale ◽

Cell Function ◽

Biomass Productivity ◽

Interactive Effects ◽

Cell Membrane Permeability ◽

Outdoor Cultivation ◽

Cultivation Conditions ◽

Light Fluctuations ◽

The Impact

Temperature and light are two of the most crucial factors for microalgae production. Variations in these factors alter their growth kinetics, macromolecular composition and physiological properties, including cell membrane permeability and fluidity. The variations define the adaptation mechanisms adopted by the microalgae to withstand changes in these environmental factors. In the Qatar desert the temperature varies widely, typically between 10° and 45 °C There are also wide variations in light intensity, with values of over 1500 μmolhν.m−2s−1 in summer. A study of the effects of these thermal and light fluctuations is therefore essential for large-scale outdoor production systems, especially during the summer when temperature and light fluctuations are at their highest. The aim of this work is to study the impact of temperature and light intensity variations as encountered in summer period on the Nannochloropsis QU130 strain, which was selected for its suitability for outdoor cultivation in the harsh conditions of the Qatar desert. It was carried out using lab-scale photobioreactors enabling simulation of both constant and dynamic temperature and light regimes. Biomass productivity, cell morphology and biochemical compositions were examined first in constant conditions, then in typical outdoor cultivation conditions to elucidate the adjustments in cell function in respect of fluctuations. The dynamic light and temperature were shown to have interactive effects. The application of temperature cycles under constant light led to a 13.6% increase in biomass productivity, while a 45% decrease was observed under light and temperature regimes due to the combined stress. In all cases, the results proved that N. sp. QU130 has a high level of adaptation to the wide fluctuations in light and temperature stress. This was shown through its ability to easily change its physiology (cell size) and metabolic process in response to different cultivation conditions.

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