Effects of high irradiance and iron concentration on pigment and fatty acid composition in the cyanobacterium Microcystis aeruginosa

1998 ◽  
Vol 49 (5) ◽  
pp. 399 ◽  
Author(s):  
Kathryn Walsh ◽  
Gary J. Jones ◽  
R. Hugh Dunstan

Microcystis aeruginosa Kuetzing emend. was exposed to sunlight and artificial illumination at low (1 µM) and high (31 µM) iron concentrations over a 9 h period. With sunlight and low iron, cellular carotenoid and chlorophyll a concentrations decreased linearly with time, and membrane polyunsaturated fatty acids were reduced after 9 h. With sunlight and high iron, there was near-complete loss of all pigments and reduced concentrations of all major fatty acids within 3 h, presumably due to photooxidation; almost all phytol, poly- and monounsaturated fatty acids were absent after 9 h exposure in the high iron medium, indicating total destruction of membranes by iron-enhanced photooxidation. Although caution is required in extrapolating results from laboratory grown cultures to field populations, it is conceivable that high irradiance can influence the composition of cyanobacterial membranes during natural surface blooms. The subsequent survival and regeneration of cyanobacterial cells may be affected under the high iron concentrations which can occur in Australian inland lakes and rivers.

2004 ◽  
pp. 27-32
Author(s):  
László Lévai

The amounts of Fe, and Zn were measured in maize seedlings infected by smut gall tumour (Ustilago maydis Dc. Cda.) and in healthy seedlings five days after infection. The amount of elements was also measured under different stress intensities. Due to the infection, as a biotic stress, the amount and distribution of examined elements have been changed. On the bases of the differences in the Fe distribution between the symptoms less and tumorial leaf parts, we have come to the conclusion that the infection also effects the mobilisation of Fe and Zn inside the plants. The Fe uptake was much higher in the infected plants and the tumour development also had an effect on the uptake and distribution of the examined elements. The experiments of infecting maize seedlings by monosporidial strain of crown gall tumour showed no tumour development. We found that the monosporidial strain also acts as a biotic stress and has an effect of iron and zinc distribution. We observed a slight difference in the iron and zinc contents in the roots of corn seedlings infected by different monosporidial sporidium concentrations, while the iron and zinc contents in the shoots were increased by the intensity of the infection. The roots do not form tumours. There is no difference between the roots of the infected and healthy corn seedlings. Since the Fe and Zn contents of the shoots of infected plants depend on the intensity of the infection, we have come to the conclusion that there must exist a „special” communication system regulating the transportation of the examined elements.In the experiments with infected maize seedlings, it became necessary to get the iron chlorosis before the disease reaches the lethal phase. Although most of the iron reserves are located in the embryo, to accelerate the chlorosis, the endosperm was removed, and it was observed, that the iron chlorosis appears later in maize seedlings when the endosperm is removed. The relative chlorophyll content of the first and second leaves was measured in iron efficient and iron deficient maize seedlings at different times.The higher IAA content of tumorial plant tissues is already known. The treatment with IAA decreases the iron concentration in the shoots and in the roots of +Fe precultured plants and increases at -Fe precultured ones. The TIBA retards the shoot-to-root transport of IAA. When the seedlings were treated simultaneously with IAA and TIBA, higher iron concentrations were observed in the shoots and in the roots of corn seedlings.We found extremely high iron concentrations in the roots of infected seedlings and, in line with this, serious damage to the roots was observed that this can be caused by the high iron content generated free radicals. The results demonstrate that IAA has a role in the shoot to root communication.


Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 389
Author(s):  
Piotr Kraska ◽  
Sylwia Andruszczak ◽  
Urszula Gawlik-Dziki ◽  
Dariusz Dziki ◽  
Ewa Kwiecińska-Poppe

The aim of this study was to evaluate the nutritional value of wholemeal bread prepared from the flour of spelt wheat (Triticum aestivum ssp. spelta) that was enriched by the addition of freeze-dried spelt grain (at proportions of 4%, 8%, and 12%, respectively, in relation to the flour weight). The spelt grain used in the study was harvested at the milk dough stage (the so-called green grain). Green spelt grain was characterized by a significantly higher content of minerals namely P, Mg, Ca and Zn compared to ripe spelt grain. Additionally, it contained significantly higher amounts of amino acids (Asp, Thr, Ser, Gly, Ala, Cys, Val, Met, Ile, Leu, Phe, Lys), lipids, as well as monounsaturated fatty acids (MUFA), and omega-3 and omega-9 acids. However, it had a lower content of palmitic, stearic, and linoleic acids, polyunsaturated fatty acids (PUFA), and omega-6 acids. The results showed that the nutritional value of bread was improved by the green spelt grain, however the ω6/ω3 ratio in bread enriched with green spelt grain was slightly less favorable than in control bread. Among all the products tested, bread enriched with a 12% proportion of green spelt grain was characterized by the highest content of almost all the amino acids (except for Pro, Cys, and Met), as well as in Mg, Zn, Mn, Cu and Fe. In addition, overall acceptability of this bread was the highest. Bread enriched with 8% of green grain contained the highest amount of P, Ca, Pro, linoleic acid, PUFA, and ω 6 acids, while bread enriched with 4% of green spelt grain had the highest content of palmitic acid and saturated fatty acids.


Diabetes ◽  
1996 ◽  
Vol 45 (5) ◽  
pp. 569-575 ◽  
Author(s):  
C. C. Low ◽  
E. B. Grossman ◽  
B. Gumbiner

2020 ◽  
Vol 16 (2) ◽  
pp. 142-154 ◽  
Author(s):  
Hadi Emamat ◽  
Zahra Yari ◽  
Hossein Farhadnejad ◽  
Parvin Mirmiran

Recent evidence has highlighted that fat accumulation, particularly abdominal fat distribution, is strongly associated with metabolic disturbance. It is also well-recognized that the metabolic responses to variations in macronutrients intake can affect body composition. Previous studies suggest that the quality of dietary fats can be considered as the main determinant of body-fat deposition, fat distribution, and body composition without altering the total body weight; however, the effects of dietary fats on body composition have controversial results. There is substantial evidence to suggest that saturated fatty acids are more obesogen than unsaturated fatty acids, and with the exception of some isomers like conjugate linoleic acid, most dietary trans fatty acids are adiposity enhancers, but there is no consensus on it yet. On the other hand, there is little evidence to indicate that higher intake of the n-3 and the n-6 polyunsaturated fatty acids can be beneficial in attenuating adiposity, and the effect of monounsaturated fatty acids on body composition is contradictory. Accordingly, the content of this review summarizes the current body of knowledge on the potential effects of the different types of dietary fatty acids on body composition and adiposity. It also refers to the putative mechanisms underlying this association and reflects on the controversy of this topic.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Goc ◽  
Aleksandra Niedzwiecki ◽  
Matthias Rath

AbstractThe strain SARS-CoV-2, newly emerged in late 2019, has been identified as the cause of COVID-19 and the pandemic declared by WHO in early 2020. Although lipids have been shown to possess antiviral efficacy, little is currently known about lipid compounds with anti-SARS-CoV-2 binding and entry properties. To address this issue, we screened, overall, 17 polyunsaturated fatty acids, monounsaturated fatty acids and saturated fatty acids, as wells as lipid-soluble vitamins. In performing target-based ligand screening utilizing the RBD-SARS-CoV-2 sequence, we observed that polyunsaturated fatty acids most effectively interfere with binding to hACE2, the receptor for SARS-CoV-2. Using a spike protein pseudo-virus, we also found that linolenic acid and eicosapentaenoic acid significantly block the entry of SARS-CoV-2. In addition, eicosapentaenoic acid showed higher efficacy than linolenic acid in reducing activity of TMPRSS2 and cathepsin L proteases, but neither of the fatty acids affected their expression at the protein level. Also, neither reduction of hACE2 activity nor binding to the hACE2 receptor upon treatment with these two fatty acids was observed. Although further in vivo experiments are warranted to validate the current findings, our study provides a new insight into the role of lipids as antiviral compounds against the SARS-CoV-2 strain.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1831
Author(s):  
Natalia Herrera ◽  
Fernando Echeverri

Although several theories have been postulated to explain cyanobacterial blooms, their biochemical origin has not yet been found. In this work, we explore the existence of bacterial communication, called quorum sensing, in Microcystis aeruginosa and Cylindrospermopsis raciborskii. Thus, the application of several known acylhomoserine lactones to cultures of both cyanobacteria causes profound metabolic. At 72 h post-application, some of them produced substantial increases in cell proliferation, while others were inhibitors. There was a correlation with colony-forming activity for most of them. According to ELISA analysis, the microcystin levels were increased with some lactones. However, there was a clear difference between M. aeruginosa and C. raciborskii culture since, in the first one, there was an inducing effect on cell proliferation, while in C. raciborskii, the effects were minor. Besides, there were compound inhibitors and inducers of microcystins production in M. aeruginosa, but almost all compounds were only inducers of saxitoxin production in C. raciborskii. Moreover, each lactone appears to be involved in a specific quorum sensing process. From these results, the formation of cyanobacterial blooms in dams and reservoirs could be explained since lactones may come from cyanobacteria and other sources as bacterial microflora-associated or exogenous compounds structurally unrelated to lactones, such as drugs, industrial effluents, and agrochemicals.


Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 1003
Author(s):  
Elena Vega-Martín ◽  
Marta Gil-Ortega ◽  
Raquel González-Blázquez ◽  
Sara Benedito ◽  
Jesús Fernández-Felipe ◽  
...  

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.


2009 ◽  
Vol 4 (10) ◽  
pp. 1934578X0900401 ◽  
Author(s):  
Christel Brunschwig ◽  
François Xavier Collard ◽  
Jean-Pierre Bianchini ◽  
Phila Raharivelomanana

In order to establish a chemical fingerprint of vanilla diversity, thirty samples of V. planifolia J. W. Moore and V. tahitensis G. Jackson cured beans from seven producing countries were examined for their aroma and fatty acid contents. Both fatty acid and aroma compositions were found to vary between vanilla species and origins. Vanillin was found in higher amounts in V. planifolia (1.7-3.6% of dry matter) than in V. tahitensis (1.0-2.0%), and anisyl compounds were found in lower amounts in V. planifolia (0.05%) than in V. tahitensis (1.4%-2.1%). Ten common and long chain monounsaturated fatty acids (LCFA) were identified and were found to be characteristic of the vanilla origin. LCFA derived from secondary metabolites have discriminating compositions as they reach 5.9% and 15.8% of total fatty acids, respectively in V. tahitensis and V. planifolia. This study highlights the role of the curing method as vanilla cured beans of two different species cultivated in the same country were found to have quite similar fatty acid compositions.


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