scholarly journals Transcriptomic analysis of Chlorella sp. HS2 suggests the overflow of acetyl‐CoA and NADPH cofactor induces high lipid accumulation and halotolerance

2020 ◽  
Author(s):  
Jin‐Ho Yun ◽  
Michaël Pierrelée ◽  
Dae‐Hyun Cho ◽  
Urim Kim ◽  
Jina Heo ◽  
...  
Keyword(s):  
Lipid Accumulation ◽  
Transcriptomic Analysis ◽  
Acetyl Coa ◽  
Chlorella Sp ◽  
High Lipid

scholarly journals Initial study of lipid accumulation in green algal Haematococcus pluvialis Flotow cultured in liquid Bold’s Basal medium aerated

2019 ◽  
Vol 3 (3) ◽  
pp. 144-149
Author(s):  
Nguyen Tran Dong Phuong ◽  
Le Huyen Ai Thuy ◽  
Bui Trang Viet
Keyword(s):  
Lipid Accumulation ◽  
Fatty Acid Biosynthesis ◽  
Haematococcus Pluvialis ◽  
Acyl Carrier Protein ◽  
Nile Red ◽  
Basal Medium ◽  
Initial Study ◽  
Rt Pcr ◽  
Green Algal ◽  
High Lipid

The fresh green algal Haematococcus pluvialis Flotow was proved to be the starting material for the production of biofuel, high lipid content along with astaxanthin, a high value colorant. In this study, lipid accumulation in H. pluvialis cultured in liquid Bold’s Basal medium aerated was investigated for a period of 12 weeks. Lipid accumulation was evaluated through the expression of two genes: BC (biotin carboxylase, initial gene) and FATA (acyl-acyl carrier protein thioesterase, end gene) in the process of fatty acid biosynthesis with Real-time RT-PCR, lipid determination by Nile Red and biodiesel quantifying by transesterification. The results showed that the expression of two BC and FATA genes was recorded at all weeks of culture. However, the expression of BC and FATA genes increased gradually from the week 9 (1.3, 4.1, respectively) to week 11 (1.7, 30.9, respectively). Meanwhile, yellow fluorescence in the microalgal cells showed that lipid appeared from week 6 to week 12. The obtained biodiesel increased slowly from week 8 (0.036 mg/mL) to week 12 (0.041 mg/mL). At week 11, the expression values of both BC gene (1.7) and FATA gene (30.9) were maximized, leading to the highest biodiesel content at the week 12.

Effects of different nitrogen sources and light paths of flat plate photobioreactors on the growth and lipid accumulation of Chlorella sp. GN1 outdoors

2020 ◽  
Vol 301 ◽  
pp. 122762 ◽  
Author(s):  
Pingzhong Feng ◽  
Zhongbin Xu ◽  
Lei Qin ◽  
Md Asraful Alam ◽  
Zhongming Wang ◽  
...  
Keyword(s):  
Flat Plate ◽  
Lipid Accumulation ◽  
Nitrogen Sources ◽  
Chlorella Sp

RNA-Seq-mediated transcriptomic analysis of heat stress response in a polar Chlorella sp. (Trebouxiophyceae, Chlorophyta)

2018 ◽  
Vol 30 (6) ◽  
pp. 3103-3119 ◽  
Author(s):  
Sze-Wan Poong ◽  
Kok-Keong Lee ◽  
Phaik-Eem Lim ◽  
Tun-Wen Pai ◽  
Chiew-Yen Wong ◽  
...  
Keyword(s):  
Heat Stress ◽  
Stress Response ◽  
Transcriptomic Analysis ◽  
Rna Seq ◽  
Heat Stress Response ◽  
Chlorella Sp

Effect of phosphorus on lipid accumulation in freshwater microalga Chlorella sp.

2012 ◽  
Vol 25 (1) ◽  
pp. 311-318 ◽  
Author(s):  
Kehong Liang ◽  
Qinghua Zhang ◽  
Ming Gu ◽  
Wei Cong
Keyword(s):  
Lipid Accumulation ◽  
Chlorella Sp

Comparison in growth, lipid accumulation, and nutrient removal capacities of Chlorella sp. in secondary effluents under sterile and non-sterile conditions

2013 ◽  
Vol 69 (3) ◽  
pp. 573-579 ◽  
Author(s):  
Qiao Zhang ◽  
Yu Hong
Keyword(s):  
Growth Rates ◽  
Nutrient Removal ◽  
Lipid Accumulation ◽  
Algal Biomass ◽  
Algal Growth ◽  
Chlorella Sp ◽  
Algal Lipid ◽  
Secondary Effluents ◽  
Removal Efficiencies ◽  
Biomass Increase

The growth, lipid accumulation and nutrient removal characteristics of an oleaginous microalga Chlorella sp. HQ in two types of secondary effluents (named as X and Q) before/after sterilization were evaluated. The results show that the algal growth rates under sterilization were higher than those under non-sterilization. However, sterilization caused a significant decrease in algal lipid and triacylglycerol (TAG) contents in both X and Q. And the lipid and TAG yields in non-sterile X were as much as 2.7 and 7.7 times higher than those in sterile X, reaching up to 51.3 and 16.1 mg L−1, respectively. However, the sterilization caused algal biomass increase in sample Q. Sterilization or not had almost no effect on the total phosphorus (TP) removal ability of Chlorella sp. HQ and it was found to have similar abilities to remove almost 100.0% TP from samples X and Q. While the total nitrogen (TN) removal efficiencies were promoted slightly under non-sterilization, increasing from 88.5 to 89.7% in X and from 13.3 to 17.2% in Q. Hence, non-sterile circumstances are basically beneficial for Chlorella sp. HQ to accumulate its lipid (TAGs) and remove nutrients from wastewater.

scholarly journals A Mathematical Model of Neutral Lipid Content in terms of Initial Nitrogen Concentration and Validation in Coelastrum sp. HA-1 and Application in Chlorella sorokiniana

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Zhenhua Yang ◽  
Yue Zhao ◽  
Zhiyong Liu ◽  
Chenfeng Liu ◽  
Zhipeng Hu ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Lipid Content ◽  
Lipid Accumulation ◽  
Nitrogen Concentration ◽  
Lipid Production ◽  
Lipid Synthesis ◽  
Quantitative Relationship ◽  
Chlorella Sorokiniana ◽  
High Lipid ◽  
Nitrogen Concentrations

Microalgae are considered to be a potential major biomass feedstock for biofuel due to their high lipid content. However, no correlation equations as a function of initial nitrogen concentration for lipid accumulation have been developed for simplicity to predict lipid production and optimize the lipid production process. In this study, a lipid accumulation model was developed with simple parameters based on the assumption protein synthesis shift to lipid synthesis by a linear function of nitrogen quota. The model predictions fitted well for the growth, lipid content, and nitrogen consumption of Coelastrum sp. HA-1 under various initial nitrogen concentrations. Then the model was applied successfully in Chlorella sorokiniana to predict the lipid content with different light intensities. The quantitative relationship between initial nitrogen concentrations and the final lipid content with sensitivity analysis of the model were also discussed. Based on the model results, the conversion efficiency from protein synthesis to lipid synthesis is higher and higher in microalgae metabolism process as nitrogen decreases; however, the carbohydrate composition content remains basically unchanged neither in HA-1 nor in C. sorokiniana.

scholarly journals Phosphorylation of Acetyl-CoA Carboxylase by AMPK Reduces Renal Fibrosis and Is Essential for the Anti-Fibrotic Effect of Metformin

2018 ◽  
Vol 29 (9) ◽  
pp. 2326-2336 ◽  
Author(s):  
Mardiana Lee ◽  
Marina Katerelos ◽  
Kurt Gleich ◽  
Sandra Galic ◽  
Bruce E. Kemp ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Epithelial Cells ◽  
Lipid Accumulation ◽  
Acid Oxidation ◽  
Acetyl Coa Carboxylase ◽  
Tubular Epithelial Cells ◽  
Acetyl Coa ◽  
Expression Of Genes ◽  
Energy Sensing ◽  
Unilateral Ureteric Obstruction

BackgroundExpression of genes regulating fatty acid metabolism is reduced in tubular epithelial cells from kidneys with tubulointerstitial fibrosis (TIF), thus decreasing the energy produced by fatty acid oxidation (FAO). Acetyl-CoA carboxylase (ACC), a target for the energy-sensing AMP-activating protein kinase (AMPK), is the major controller of the rate of FAO within cells. Metformin has a well described antifibrotic effect, and increases phosphorylation of ACC by AMPK, thereby increasing FAO.MethodsWe evaluated phosphorylation of ACC in cell and mouse nephropathy models, as well as the effects of metformin administration in mice with and without mutations that reduce ACC phosphorylation.ResultsReduced phosphorylation of ACC on the AMPK site Ser79 occurred in both tubular epithelial cells treated with folate to mimic cellular injury and in wild-type (WT) mice after induction of the folic acid nephropathy model. When this effect was exaggerated in mice with knock-in (KI) Ser to Ala mutations of the phosphorylation sites in ACC, lipid accumulation and fibrosis increased significantly compared with WT. The effect of ACC phosphorylation on fibrosis was confirmed in the unilateral ureteric obstruction model, which showed significantly increased lipid accumulation and fibrosis in the KI mice. Metformin use was associated with significantly reduced fibrosis and lipid accumulation in WT mice. In contrast, in the KI mice, the drug was associated with worsened fibrosis.ConclusionsThese data indicate that reduced phosphorylation of ACC after renal injury contributes to the development of TIF, and that phosphorylation of ACC is required for metformin’s antifibrotic action in the kidney.

scholarly journals Molecular Mechanism of Citrate Efflux by the Mitochondrial Citrate Transporter CT in Filamentous Fungus Mucor circinelloides WJ11

2021 ◽  
Vol 12 ◽  
Author(s):  
Wu Yang ◽  
Shiqi Dong ◽  
Junhuan Yang ◽  
Hassan Mohamed ◽  
Aabid Manzoor Shah ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Filamentous Fungus ◽  
Lipid Accumulation ◽  
High Efficiency ◽  
Mucor Circinelloides ◽  
Transport Activity ◽  
Citrate Transport ◽  
Citrate Transporter ◽  
High Lipid ◽  
Citrate Efflux

The mitochondrial citrate transporter (MCT) plays an important role in citrate efflux from the mitochondria in eukaryotes, and hence provides a direct correlation between carbohydrate metabolism and lipid synthesis. Our previous studies on transporters confirmed the presence of two MCTs (TCT and CT) in oleaginous Mucor circinelloides WJ11 associated with high lipid accumulation. However, the molecular mechanism of citrate efflux from the mitochondria by MCT in M. circinelloides is still unclear. To study the citrate transport mechanism of CT, the citrate transporter gene was expressed in Escherichia coli, and its product was purified. The citrate transport activity of the protein was studied in CT reconstituted liposomes. Our results showed high efficiency of CT for [14C] citrate/citrate exchange with Km 0.01 mM at 25°C. Besides citrate, other molecules such as oxaloacetate, malate, fumarate, succinate aconitate, oxoadipate, isocitrate, and glutamate also promote citrate transport. In addition, the ct overexpression and knockout plasmids were constructed and transferred into M. circinelloides WJ11, and the mitochondria were isolated, and the transport activity was studied. Our findings showed that in the presence of 10 mM malate, the mitochondria of ct-overexpressing transformant showed 51% increase in the efflux rate of [14C] citrate, whereas the mitochondria of the ct-knockout transformant showed 18% decrease in citrate efflux compared to the mitochondria of wild-type WJ11. This study provided the first mechanistic evidence of citrate efflux from the mitochondria by citrate transporter in oleaginous filamentous fungus M. circinelloides, which is associated with high lipid accumulation.

scholarly journals Synthesis of neutral lipids in chlorella sp. under different light and carbonate conditions

2011 ◽  
Vol 4 (4) ◽  
pp. 47-57 ◽  
Author(s):  
Jazmín-Vanessa Pérez-Pazos ◽  
Pablo Fernández-Izquierdo
Keyword(s):  
Neutral Lipids ◽  
Lipid Production ◽  
Red Light ◽  
Lipid Synthesis ◽  
Basal Medium ◽  
Chlorella Sp ◽  
High Lipid ◽  
The Right ◽  
Two Stages ◽  
Physical And Chemical

Lipids are biomolecules of great scientific and biotechnological interest due to their extensive applications. Microalgae are potential biological systems used in the synthesis of lipids, particularly Chlorella sp., which is characterized by its high lipid content and for having the right profile for the obtainment of biofuel. Lipid production in microalgae is influenced by several physical and chemical factors. Any modification thereof can cause a stress response represented by changes in synthesized lipid composition, varying from one species to another. This paper evaluates the effect of different light wavelengths, photoperiods and calcium carbonate (CaCO3) supply in lipid synthesis in Chlorella sp. In order to do so, the microalgae was grown in Bold's Basal Medium (BBM) at 20ºC with constant aeration and subject to low blue (470 nm) and red (700 nm) light wavelengths, 0,5 g.L-1 and 1,5 g.L-1 concentrations of CaCO3 and 6-hour light, 18-hour darkness (6:18) and 18-hour light, 6-hour darkness (18:6) photoperiods. The results indicate a higher growth rate for microalgae under red light, 0,5 g.L-1 of CaCO3 and a photoperiod of 6:18. On the other hand, lipid production is higher under blue light, 1,5 g.L-1 of CaCO3 and an18:6 photoperiod. Analysis by gas chromatography indicate that the fatty acids in the samples are oleic, linoleic and palmitoleic, which are of recognized importance in the biodiesel industry. This suggests that neutral lipid synthesis can be optimized in two stages: first, by promoting growth and subsequently, by inducing lipid production.

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