scholarly journals Identification of Six Thiolases and their Effects on Fatty Acid and Ergosterol Biosynthesis in Aspergillus oryzae

2021 ◽  
Author(s):  
Hui Huang ◽  
Yali Niu ◽  
Qi Jin ◽  
Kunhai Qin ◽  
Li Wang ◽  
...  

AbstractThiolase plays important roles in lipid metabolism. It can be divided into degradative thiolases (Thioase I) and biosynthetic thiolases (thiolases II), which are involved in fatty acid β-oxidation and acetoacetyl-CoA biosynthesis, respectively. The Saccharomyces cerevisiae (S. cerevisiae) genome harbors only one gene each for thioase I and thiolase II, namely, Pot1 and Erg10, respectively. In this study, six thiolases (named AoErg10A−AoErg10F) were identified in Aspergillus oryzae (A. oryzae) genome using bioinformatics analysis. Quantitative reverse transcription–PCR (qRT-PCR) indicated that the expression of these six thiolases varied at different growth stages and under different forms of abiotic stress. Subcellular localization analysis showed that AoErg10A was located in the cytoplasm, AoErg10B and AoErg10C in the mitochondria, and AoErg10D-AoErg10F in the peroxisome. Yeast heterologous complementation assays revealed that AoErg10A, AoErg10D, AoErg10E, AoErg10F and cytoplasmic AoErg10B (AoErg10BΔMTS) recovered the phenotypes of S. cerevisiae erg10 weak and lethal mutants, and that only AoErg10D-F recovered the phenotype of the pot1 mutant that cannot use oleic acid as the carbon source. Overexpression of AoErg10s either affected the growth speed or sporulation of the transgenic strains. In addition, the fatty acid and ergosterol content changed in all the AoErg10-overexpressing strains. This study revealed the function of six thiolases in A. oryzae and their effect on growth, and fatty acid and ergosterol biosynthesis, which may lay the foundation for genetic engineering for lipid metabolism in A. oryzae or other fungi.ImportanceThiolase including thioase I and thiolase II, plays important roles in lipid metabolism. A. oryzae, one of the most industrially important filamentous fungi, has been widely used for manufacturing oriental fermented food such as sauce, miso, and sake for a long time. Besides, A. oryzae has a high capability in production of high lipid content and has been used for lipid production. Thus, it is very important to investiagte the function of thiolases in A. oryzae. In this study, six thiolase (named AoErg10A-AoErg10F) were identified by bioinformatics analysis. Unlike other reported thiolases in fungi, three of the six thiolases showed dual function of thioase I and thiolase II in S. cerevisiae, indicating the lipid metabolism is more complex in A. oryzae. The reveal of founction of these thiolases in A. oryzae can lay the foundation for genetic engineering for lipid metabolism in A. oryzae or other fungi.

2019 ◽  
Vol 7 (9) ◽  
pp. 342
Author(s):  
Hu ◽  
Huang ◽  
Sun ◽  
Niu ◽  
Xu ◽  
...  

Mevalonate diphosphate decarboxylase MVD/Erg19 is required for ergosterol biosynthesis, growth, sporulation, and stress tolerance in Aspergillus oryzae. In this study, RNA-seq was used to analyze the gene transcription profile in AoErg19 overexpression (OE) and RNAi strains. There were 256 and 74 differentially expressed genes (DEGs) in AoErg19 OE and RNAi strains, respectively, compared with the control strain (CK). The most common DEGs were transport- and metabolism-related genes. Only 22 DEGs were obtained that were regulated in both OE and RNAi strains. The transcriptomic comparison between CK and AoErg19 overexpression strain (CK vs. OE), and between CK and AoErg19 RNAi strain (CK vs. RNAi) revealed that the greatest difference existed in the number of genes belonging to the cytochrome P450 family; 12 were found in CK vs. OE, whereas 1 was found in CK vs. RNAi. The expression patterns of lipid biosynthesis and metabolism related genes were altered in OE and RNAi strains, either by gene induction or suppression. Moreover, the total fatty acid content in the RNAi strain was 12.1% greater than the control strain, but no difference in total acid content was found between the overexpression strain and the control strain. Therefore, this study highlights the gene expression regulation within mevalonate (MVA), ergosterol biosynthesis, and fatty acid biosynthesis pathways.


2019 ◽  
Author(s):  
Jeong-Won Nam ◽  
Lauren M. Jenkins ◽  
Jia Li ◽  
Bradley S. Evans ◽  
Jan G. Jaworski ◽  
...  

ABSTRACTAcyl carrier proteins (ACPs) are the scaffolds for fatty acid biosynthesis in living systems, rendering them essential to a comprehensive understanding of lipid metabolism; however, accurate quantitative methods to assess individual acyl-ACPs do not exist. A robust method was developed to quantify acyl-ACPs at picogram levels. Acyl-ACP elongation intermediates (3-hydroxyacyl-ACPs and 2, 3-trans-enoyl-ACPs), and unexpected medium chain (C10:1, C14:1) and polyunsaturated long chain acyl-ACPs (C16:3) were also identified, indicating the sensitivity of the method and that descriptions of lipid metabolism and ACP function are incomplete. Such ACPs are likely important to medium chain lipid production for fuels and highlight poorly understood lipid remodeling events in the chloroplast. The approach is broadly applicable to Type II FAS systems found in plants, bacteria, and mitochondria of animal and fungal systems because it uses a strategy that capitalizes on a highly conserved Asp-Ser-Leu-Asp (DSLD) amino acid sequence in ACPs to which acyl groups are attached. This allows for sensitive quantification using LC-MS/MS with de novo generated standards and an isotopic dilution strategy and will fill a gap in understanding, providing insights through quantitative exploration of fatty acid biosynthesis processes for optimal biofuels, renewable feed stocks, and medical studies in health and disease.


Author(s):  
Ikumi Umetani ◽  
Eshetu Janka ◽  
Michal Sposób ◽  
Chris J. Hulatt ◽  
Synne Kleiven ◽  
...  

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.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zheng Ma ◽  
Na Luo ◽  
Lu Liu ◽  
Huanxian Cui ◽  
Jing Li ◽  
...  

Abstract Background A body distribution with high intramuscular fat and low abdominal fat is the ideal goal for broiler breeding. Preadipocytes with different origins have differences in terms of metabolism and gene expression. The transcriptome analysis performed in this study of intramuscular preadipocytes (DIMFPs) and adipose tissue-derived preadipocytes (DAFPs) aimed to explore the characteristics of lipid deposition in different chicken preadipocytes by dedifferentiation in vitro. Results Compared with DAFPs, the total lipid content in DIMFPs was reduced (P < 0.05). Moreover, 72 DEGs related to lipid metabolism were screened, which were involved in adipocyte differentiation, fatty acid transport and fatty acid synthesis, lipid stabilization, and lipolysis. Among the 72 DEGs, 19 DEGs were enriched in the PPAR signaling pathway, indicating its main contribution to the regulation of the difference in lipid deposition between DAFPs and DIMFPs. Among these 19 genes, the representative APOA1, ADIPOQ, FABP3, FABP4, FABP7, HMGCS2, LPL and RXRG genes were downregulated, but the ACSL1, FABP5, PCK2, PDPK1, PPARG, SCD, SCD5, and SLC27A6 genes were upregulated (P < 0.05 or P < 0.01) in the DIMFPs. In addition, the well-known pathways affecting lipid metabolism (MAPK, TGF-beta and calcium) and the pathways related to cell communication were enriched, which may also contribute to the regulation of lipid deposition. Finally, the regulatory network for the difference in lipid deposition between chicken DAFPs and DIMFPs was proposed based on the above information. Conclusions Our data suggested a difference in lipid deposition between DIMFPs and DAFPs of chickens in vitro and proposed a molecular regulatory network for the difference in lipid deposition between chicken DAFPs and DIMFPs. The lipid content was significantly increased in DAFPs by the direct mediation of PPAR signaling pathways. These findings provide new insights into the regulation of tissue-specific fat deposition and the optimization of body fat distribution in broilers.


1961 ◽  
Vol 200 (4) ◽  
pp. 847-850 ◽  
Author(s):  
Judith K. Patkin ◽  
E. J. Masoro

Cold acclimation is known to alter hepatic lipid metabolism. Liver slices from cold-acclimated rats have a greatly depressed capacity to synthesize long-chain fatty acids from acctate-1-C14. Since adipose tissue is the major site of lipogenic activity in the intact animal, its fatty acid synthetic capacity was studied. In contrast to the liver, it was found that adipose tissue from the cold-acclimated rat synthesized three to six times as much long-chain fatty acids per milligram of tissue protein as the adipose tissue from the control rat living at 25°C. Evidence is presented indicating that adipose tissue from cold-acclimated and control rats esterify long-chain fatty acids at the same rate. The ability of adipose tissue to oxidize palmitic acid to CO2 was found to be unaltered by cold acclimation. The fate of the large amount of fatty acid synthesized in the adipose tissue of cold-acclimated rats is discussed.


Author(s):  
Manoharan Balachandiran ◽  
Zachariah Bobby ◽  
Gowri Dorairajan ◽  
Sajini Elizabeth Jacob ◽  
Victorraj Gladwin ◽  
...  

Abstract Introduction Gestational diabetes mellitus (GDM) exhibit altered placental lipid metabolism. The molecular basis of this altered metabolism is not clear. Altered placental expression of proteins of lipogenesis and fatty acid oxidation may be involved in the placental accumulation of triacylglycerols (TG). The present study was aimed at investigating the differential expressions of placental proteins related to lipid metabolism among GDM women in comparison with control pregnant women (CPW) and to correlate them with maternal and fetal lipid parameters as well as altered fetal growth. Materials and Methods Maternal blood, cord blood, and placental samples were collected from GDM and CPW. The biochemical parameters, glucose, lipid profile and free fatty acids (FFA) were measured. The placental TG content was measured. Differential placental expressions of proteins; phosphatidylinositol-3-kinase (PI3K) p85α, PI3K p110α,liver X receptor alpha (LXRα), sterol regulatory element binding protein1(SREBP1), fatty acid synthase (FAS), stearyl CoA desaturase1 (SCD1), lipoprotein lipase (LPL),Peroxisome proliferator-activated receptor (PPAR)α and PPARγ were analysed by western blotting and immunohistochemistry. Results Placental protein expressions of PI3K p110α, LXRα, FAS, SCD1, and LPL were found to be significantly higher, whereas PPARα and PPARγ were lower in GDM women compared with CPW. The placental TG content and cord plasma FFA were increased in GDM women compared with CPW. The placental TG content positively correlated with Ponderal index of GDM new-borns. Conclusion Differential expressions of placental proteins related to lipid metabolism in GDM might have led to placental TG accumulation. This might have contributed to the fetal overgrowth in GDM.


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