scholarly journals Effects of light intensity on growth and lipid production in microalgae grown in wastewater

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Jean Claude Nzayisenga ◽  
Xavier Farge ◽  
Sophia Leticia Groll ◽  
Anita Sellstedt
Keyword(s):  
Fatty Acid ◽  
Light Intensity ◽  
Acid Content ◽  
Acid Production ◽  
Fatty Acid Content ◽  
Lipid Production ◽  
Scenedesmus Obliquus ◽  
Biodiesel Production ◽  
Fatty Acid Production ◽  
Light Intensities

Abstract Background Cultivation of microalgae in wastewater could significantly contribute to wastewater treatment, biodiesel production, and thus the transition to renewable energy. However, more information on effects of environmental factors, including light intensity, on their growth and composition (particularly fatty acid contents) is required. Therefore, we investigated the biomass and fatty acid production of four microalgal species, isolated in the Northern hemisphere and grown at three light intensities (50, 150 and 300 μE m−2 s−1). Results Increases in light intensities resulted in higher biomass of all four species and, importantly, raised fatty acid contents of both Desmodesmus sp. and Scenedesmus obliquus. Fourier-transform IR spectrometry analysis showed that the increases in fatty acid content were associated with reductions in protein, but not carbohydrate, contents. Assessment of fatty acid composition revealed that increasing light intensity led to higher and lower contents of oleic (18:1) and linolenic (18:3) acids, respectively. The microalgae consumed more than 75% of the nitrogen and phosphorus present in the wastewater used as growth medium. Conclusion The results show the importance of optimizing light intensities to improve fatty acid production by microalgae and their quality as sources of biodiesel. In addition, increase in fatty acid content is associated with decrease in protein content.

Effect of light intensity on the ultrastructure of the filamentous cyanobacterium, Anabaena variabilis

1988 ◽  
Vol 46 ◽  
pp. 300-301
Author(s):  
C. S. Bricker ◽  
S. R. Barnum ◽  
B. Huang ◽  
J. G. Jaworskl
Keyword(s):  
Fatty Acid ◽  
Light Intensity ◽  
Acid Content ◽  
Fatty Acid Content ◽  
Anabaena Variabilis ◽  
Chloroplast Envelope ◽  
Major Constituent ◽  
Filamentous Cyanobacterium ◽  
Photosynthetic Membrane ◽  
Effect Of Light

Cyanobacteria are Gram negative prokaryotes that are capable of oxygenic photosynthesis. Although there are many similarities between eukaryotes and cyanobacteria in electron transfer and phosphorylation during photosynthesis, there are two features of the photosynthetic apparatus in cyanobacteria which distinguishes them from plants. Cyanobacteria contain phycobiliproteins organized in phycobilisomes on the surface of photosynthetic membrane. Another difference is in the organization of the photosynthetic membranes. Instead of stacked thylakolds within a chloroplast envelope membrane, as seen In eukaryotes, IntracytopIasmlc membranes generally are arranged in three to six concentric layers. Environmental factors such as temperature, nutrition and light fluency can significantly affect the physiology and morphology of cells. The effect of light Intensity shifts on the ultrastructure of Internal membrane in Anabaena variabilis grown under controlled environmental conditions was examined. Since a major constituent of cyanobacterial thylakolds are lipids, the fatty acid content also was measured and correlated with uItrastructural changes. The regulation of fatty acid synthesis in cyanobacteria ultimately can be studied if the fatty acid content can be manipulated.

scholarly journals Activating de novo triacylglycerol synthesis in oleaginous yeast for improved bio-diesel quality

2018 ◽  
Vol 4 (2) ◽  
pp. 16-24
Author(s):  
Farha Deeba ◽  
Ruchir Priyadarshi ◽  
Vikas Pruthi ◽  
Yuvraj Singh Negi
Keyword(s):  
Fatty Acid ◽  
Sodium Bicarbonate ◽  
Acid Content ◽  
Oleaginous Yeast ◽  
De Novo ◽  
Fatty Acid Content ◽  
Biodiesel Production ◽  
Nitrogen Base ◽  
Triacylglycerol Synthesis ◽  
Tag Accumulation

The economic production of yeast biofuels requires several strategies, such as multiomics techniques to gain insights into lipid biosynthesis pathway. Hence, metabolomic studies for amelioration of triacylglycerol (TAG) accumulation in oleaginous yeast strain to reveal potential targets in fatty acid synthesis pathway should be explored. The aim of this research experiment was to boost TAG agglomeration in novel isolated oleaginous yeast Cryptococcus psychrotolerans IITRFD using sodium bicarbonate as supplement for biodiesel production. Enhanced biomass productivity (83.5 ± 0.32 mg/L/h) and lipid productivity (56.8 ± 0.34 mg/L/h) have been estimated as compared to yeast nitrogen base media (YNB) used as control. Also, the bicarbonate supplementation (25 mM) leads to decrease in phospholipids (23.6 %) while increase in TAG amount (75.4 %) signifying that it redirects the phospholipids synthesis pathway in the direction of de novo TAG pathway. The fatty acid profile obtained revealed rise in monounsaturated fatty acid content and decrease in polyunsaturated fatty acid content demonstrating better oxidative stability (19 h) and cold flow behaviour (- 12 °C) of biodiesel produced. This novel strategy of utilizing bicarbonate as a triggering system may possibly revamp the commercial use of C. psychrotolerans IITRFD for high quality biodiesel production. This is the first study to augment TAG accumulation in this oleaginous yeast using sodium bicarbonate with improved fuel properties.

scholarly journals Characterization of NAD+/NADP+-Specific Isocitrate Dehydrogenases From Oleaginous Fungus Mortierella alpina Involved in Lipid Accumulation

2021 ◽  
Vol 8 ◽  
Author(s):  
Xin Tang ◽  
Xiaoqi Sun ◽  
Xuxu Wang ◽  
Hao Zhang ◽  
Yong Q. Chen ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Accumulation ◽  
Acid Content ◽  
Carbon Flux ◽  
Tricarboxylic Acid Cycle ◽  
Fatty Acid Content ◽  
Lipid Production ◽  
Reducing Power ◽  
Total Lipid Content ◽  
Mortierella Alpina

Mortierella alpina has a strong capacity for lipid accumulation. Isocitrate dehydrogenase (IDH) plays an important role in affecting the flow of intracellular carbon sources and reducing power NADPH for lipid biosynthesis. In this study, the effect of various IDHs (NAD+- and NADP+-specific) in M. alpina on the lipid accumulation was investigated through homologous overexpression. The results showed that the transcription level and enzyme activity of the IDHs from M. alpina (MaIDHs) in homologous overexpressing strains were higher than those of the control strain, but that their biomass was not significantly different. Among the various NAD+-specific MaIDH1/2/3 overexpression, NAD+-MaIDH3 reduced total lipid content by 12.5%, whereas overexpression NAD+-MaIDH1 and NAD+-MaIDH2 had no effect on fatty acid content. Intracellular metabolites analysis indicated that the overexpression NAD+-MaIDH3 strain had reduced the fatty acid accumulation, due to its greater carbon flux with the tricarboxylic acid cycle and less carbon flux with fatty acid biosynthesis. For the NADP+-MaIDH4/5/6 recombinant strains overexpressing only NADP+-MaIDH4 enhanced the total fatty acid content by 8.2%. NADPH analysis suggested that this increase in lipid accumulation may have been due to the great reducing power NADPH is produced in this recombinant strain. This study provides theoretical basis and guidance for the analysis of the mechanism of IDH function and the potential to improve lipid production in M. alpina.

Incomplete fatty acid oxidation by ischemic heart: beta-hydroxy fatty acid production

1980 ◽  
Vol 239 (2) ◽  
pp. H257-H265 ◽  
Author(s):  
K. H. Moore ◽  
J. F. Radloff ◽  
F. E. Hull ◽  
C. C. Sweeley
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Acid Production ◽  
Hydroxy Fatty Acid ◽  
Oxygen Deficiency ◽  
Fatty Acid Content ◽  
Hydroxy Fatty Acids ◽  
Ischemic Heart ◽  
Fatty Acid Production ◽  
Exogenous Fatty Acid

A quantitative gas chromatography-mass spectrometry (GC/MS) method was developed to measure nanomolar quantities of long-chain saturated beta-hydroxy fatty acids (12, 14, 16, and 18 carbons long) produced by isolated ischemic heart. Only beta-hydroxymyristate (25-40 nmol/g dry) was found in fresh heart. Isolated rabbit heart perfused with fatty acid by the nonrecirculating Langendorff technique produced negligible beta-hydroxy fatty acids. Ischemic perfusion with 0.25-0.75 mM palmitate prompted heart beta-hydroxy fatty acid accumulation, beta-hydroxypalmitate greater than beta-hydroxystearate, up to 100 nmol x g dry-1 x 10 min-1. beta-Hydroxy fatty acid production was proportional to coronary effluent lactate-to pyruvate ratio, did not continue beyond 10 min of ischemia, was dependent on exogenous fatty acid, and was inhibited by coperfusion with 10 mM acetate. Reperfusion for 5-10 min dissipated accumulated beta-hydroxypalmitate. Hypoxic perfusion prompted beta-hydroxy fatty acid production comparable to that with severe ischemia. These data show that during oxygen deficiency heart fatty acid beta-oxidation is not only depressed but is also incomplete; beta-hydroxy fatty acyl intermediates accumulate and contribute to the increased intracellular fatty acid content characteristic of the ischemic myocardium.

Sign in / Sign up

Export Citation Format

Share Document