scholarly journals Fatty Acid Production and Direct Acyl Transfer through Polar Lipids Control TAG Biosynthesis during Nitrogen Deprivation in the Halotolerant Alga Dunaliella tertiolecta

Marine Drugs ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 368
Author(s):  
Omri Avidan ◽  
Sergey Malitsky ◽  
Uri Pick
Keyword(s):  
Fatty Acid ◽  
Dunaliella Tertiolecta ◽  
Acyl Transfer ◽  
Major Polar Lipid ◽  
Nitrogen Deprivation ◽  
Fatty Acid Production ◽  
Time Resolved ◽  
Partial Suppression ◽  
Tag Biosynthesis ◽  
State Concentration

The aims of this work were to evaluate the contribution of the free fatty acid (FA) pool to triacylglyceride (TAG) biosynthesis and to try to characterize the mechanism by which FA are assimilated into TAG in the green alga Dunaliella tertiolecta. A time-resolved lipidomic analysis showed that nitrogen (N) deprivation induces a redistribution of total lipidome, particularly of free FA and major polar lipid (PL), in parallel to enhanced accumulation of polyunsaturated TAG. The steady-state concentration of the FA pool, measured by prolonged 14C-bicarbonate pre-labeling, showed that N deprivation induced a 50% decrease in total FA level within the first 24 h and up to 85% after 96 h. The abundance of oleic acid increased from 50 to 70% of total free FA while polyunsaturated FA (PUFA) disappeared under N deprivation. The FA flux, measured by the rate of incorporation of 14C-palmitic acid (PlA), suggests partial suppression of phosphatidylcholine (PC) acyl editing and an enhanced turnover of the FA pool and of total digalactosyl-diacylglycerol (DGDG) during N deprivation. Taken together, these results imply that FA biosynthesis is a major rate-controlling stage in TAG biosynthesis in D. tertiolecta and that acyl transfer through PL such as PC and DGDG is the major FA assimilation pathway into TAG in that alga and possibly in other green microalgae. Increasing the availability of FA could lead to enhanced TAG biosynthesis and to improved production of high-value products from microalgae.

scholarly journals TILLING-by-Sequencing+ Reveals the Role of Novel Fatty Acid Desaturases (GmFAD2-2s) in Increasing Soybean Seed Oleic Acid Content

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1245
Author(s):  
Naoufal Lakhssassi ◽  
Valéria Stefania Lopes-Caitar ◽  
Dounya Knizia ◽  
Mallory A. Cullen ◽  
Oussama Badad ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Acid Content ◽  
Edible Oils ◽  
Fatty Acid Desaturase ◽  
Soybean Seed ◽  
Oleic Acid Content ◽  
Fatty Acid Production ◽  
Tilling By Sequencing

Soybean is the second largest source of oil worldwide. Developing soybean varieties with high levels of oleic acid is a primary goal of the soybean breeders and industry. Edible oils containing high level of oleic acid and low level of linoleic acid are considered with higher oxidative stability and can be used as a natural antioxidant in food stability. All developed high oleic acid soybeans carry two alleles; GmFAD2-1A and GmFAD2-1B. However, when planted in cold soil, a possible reduction in seed germination was reported when high seed oleic acid derived from GmFAD2-1 alleles were used. Besides the soybean fatty acid desaturase (GmFAD2-1) subfamily, the GmFAD2-2 subfamily is composed of five members, including GmFAD2-2A, GmFAD2-2B, GmFAD2-2C, GmFAD2-2D, and GmFAD2-2E. Segmental duplication of GmFAD2-1A/GmFAD2-1B, GmFAD2-2A/GmFAD2-2C, GmFAD2-2A/GmFAD2-2D, and GmFAD2-2D/GmFAD2-2C have occurred about 10.65, 27.04, 100.81, and 106.55 Mya, respectively. Using TILLING-by-Sequencing+ technology, we successfully identified 12, 8, 10, 9, and 19 EMS mutants at the GmFAD2-2A, GmFAD2-2B, GmFAD2-2C, GmFAD2-2D, and GmFAD2-2E genes, respectively. Functional analyses of newly identified mutants revealed unprecedented role of the five GmFAD2-2A, GmFAD2-2B, GmFAD2-2C, GmFAD2-2D, and GmFAD2-2E members in controlling the seed oleic acid content. Most importantly, unlike GmFAD2-1 members, subcellular localization revealed that members of the GmFAD2-2 subfamily showed a cytoplasmic localization, which may suggest the presence of an alternative fatty acid desaturase pathway in soybean for converting oleic acid content without substantially altering the traditional plastidial/ER fatty acid production.

A Techno-Economic case for Volatile Fatty Acid Production for Increased Sustainability in the Wastewater Treatment Industry

2021 ◽  
Author(s):  
Ganesh K Veluswamy ◽  
Andy Ball ◽  
Richard Dinsdale ◽  
Alan Guwy ◽  
Kalpit Shah
Keyword(s):  
Wastewater Treatment ◽  
Fatty Acid ◽  
Anaerobic Digestion ◽  
Acid Production ◽  
Volatile Fatty Acid ◽  
Fugitive Emissions ◽  
Fatty Acid Production

Methane, the final product of methanogenesis during anaerobic digestion is a low value product (0.1$/m3). Concerns over fugitive emissions from methane coupled with recent reduction in costs of solar and...

Gut microbiome responses to dietary intake of grain-based fibers with the potential to modulate markers of metabolic disease: a systematic literature review

2020 ◽  
Author(s):  
Georgina M Williams ◽  
Linda C Tapsell ◽  
Claire L O’Brien ◽  
Susan M Tosh ◽  
Eden M Barrett ◽  
...  
Keyword(s):  
Systematic Review ◽  
Fatty Acid ◽  
Gut Microbiome ◽  
Acid Production ◽  
Short Chain Fatty Acid ◽  
Chain Fatty Acid ◽  
Fatty Acid Production ◽  
Microbiome Diversity ◽  
Cereal Fiber ◽  
Dietary Data

Abstract Context Cereal fiber modulates the gut microbiome and benefits metabolic health. The potential link between these effects is of interest.0 Objective The aim for this systematic review was to assess evidence surrounding the influence of cereal fiber intake on microbiome composition, microbiome diversity, short-chain fatty acid production, and risk factors for metabolic syndrome. Data Sources and Extraction The MEDLINE, PubMed, CINAHL, and Cochrane Library databases were searched systematically, and quality of studies was assessed using the Cochrane Risk of Bias 2.0 tool. Evidence relating to study design, dietary data collection, and outcomes was qualitatively synthesized on the basis of fiber type. Data Analysis Forty-six primary publications and 2 secondary analyses were included. Cereal fiber modulated the microbiome in most studies; however, taxonomic changes indicated high heterogeneity. Short-chain fatty acid production, microbiome diversity, and metabolic-related outcomes varied and did not always occur in parallel with microbiome changes. Poor dietary data were a further limitation. Conclusions Cereal fiber may modulate the gut microbiome; however, evidence of the link between this and metabolic outcomes is limited. Additional research is required with a focus on robust and consistent methodology. Systematic Review Registration PROSPERO registration no. CRD42018107117

scholarly journals Bicarbonate for microalgae cultivation: a case study in a chlorophyte, Tetradesmus wisconsinensis isolated from a Norwegian lake

2021 ◽  
Author(s):  
Ikumi Umetani ◽  
Eshetu Janka ◽  
Michal Sposób ◽  
Chris J. Hulatt ◽  
Synne Kleiven ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Lipid Production ◽  
Cetane Number ◽  
Fluorescence Analysis ◽  
Dry Weight ◽  
Maximum Growth ◽  
Biodiesel Fuel ◽  
Fatty Acid Production ◽  
Total Fatty Acids

AbstractBicarbonate was evaluated as an alternative carbon source for a green microalga, Tetradesmus wisconsinensis, isolated from Lake Norsjø in Norway. Photosynthesis, growth, and lipid production were studied using four inorganic carbon regimes: (1) aeration only, (2) 20 mM NaHCO3, (3) 5% (v/v) CO2 gas, and (4) combination of 20 mM NaHCO3 and 5% CO2. Variable chlorophyll a fluorescence analysis revealed that the bicarbonate treatment supported effective photosynthesis, while the CO2 treatment led to inefficient photosynthetic activity with a PSII maximum quantum yield as low as 0.31. Conversely, bicarbonate and CO2 treatments gave similar biomass and fatty acid production. The maximum growth rate, the final cell dry weight, and total fatty acids under the bicarbonate-only treatment were 0.33 (± 0.06) day−1, 673 (± 124) mg L−1 and 75 (± 5) mg g−1 dry biomass, respectively. The most abundant fatty acid components were α-linolenic acid and polyunsaturated fatty acids constituting 69% of the total fatty acids. The fatty acid profile eventuated in unsuitable biodiesel fuel properties such as high degree of unsaturation and low cetane number; however, it would be relevant for food and feed applications. We concluded that bicarbonate could give healthy growth and comparative product yields as CO2.

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