scholarly journals Functional genomics of lipid metabolism in the oleaginous yeast Rhodosporidium toruloides

2017 ◽  
Author(s):  
Samuel T Coradetti ◽  
Dominic Pinel ◽  
Gina Geiselman ◽  
Masakazu Ito ◽  
Stephen Mondo ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Functional Genomics ◽  
Lipid Accumulation ◽  
Protein Modification ◽  
Carbon Sources ◽  
Acid Synthesis ◽  
Rhodosporidium Toruloides ◽  
Chemical Production ◽  
Amino Acid Synthesis

AbstractThe basidomycete yeast Rhodosporidium toruloides (a.k.a. Rhodotorula toruloides) accumulates high concentrations of lipids and carotenoids from diverse carbon sources. It has great potential as a model for the cellular biology of lipid droplets and for sustainable chemical production. We developed a method for high-throughput genetics (RB-TDNAseq), using sequence-barcoded Agrobacterium tumefaciens T-DNA insertions into the R. toruloides genome. We identified 1337 putative essential genes with low T-DNA insertion rates. We functionally profiled genes required for fatty acid catabolism and lipid accumulation, validating results with 35 targeted deletion strains. We found that both mitochondrial and peroxisomal enzymes were required for growth on fatty acids, with different peroxisomal enzymes required on different fatty acids. We identified a high-confidence set of 150 genes affecting lipid accumulation, including genes with predicted function in signaling cascades, gene expression, protein modification and vesicular trafficking, autophagy, amino acid synthesis and tRNA modification, as well as genes of unknown function. These results greatly advance our understanding of lipid metabolism in this oleaginous species, identify key biological processes to be further explored and optimized for production of lipid-based bioproducts, and demonstrate a general approach for barcoded mutagenesis that should enable functional genomics in diverse fungi.

scholarly journals Functional genomics of lipid metabolism in the oleaginous yeast Rhodosporidium toruloides

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Samuel T Coradetti ◽  
Dominic Pinel ◽  
Gina M Geiselman ◽  
Masakazu Ito ◽  
Stephen J Mondo ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Functional Genomics ◽  
Lipid Accumulation ◽  
Protein Modification ◽  
Carbon Sources ◽  
Acid Synthesis ◽  
Rhodosporidium Toruloides ◽  
Chemical Production ◽  
Amino Acid Synthesis ◽  
High Concentrations

The basidiomycete yeast Rhodosporidium toruloides (also known as Rhodotorula toruloides) accumulates high concentrations of lipids and carotenoids from diverse carbon sources. It has great potential as a model for the cellular biology of lipid droplets and for sustainable chemical production. We developed a method for high-throughput genetics (RB-TDNAseq), using sequence-barcoded Agrobacterium tumefaciens T-DNA insertions. We identified 1,337 putative essential genes with low T-DNA insertion rates. We functionally profiled genes required for fatty acid catabolism and lipid accumulation, validating results with 35 targeted deletion strains. We identified a high-confidence set of 150 genes affecting lipid accumulation, including genes with predicted function in signaling cascades, gene expression, protein modification and vesicular trafficking, autophagy, amino acid synthesis and tRNA modification, and genes of unknown function. These results greatly advance our understanding of lipid metabolism in this oleaginous species and demonstrate a general approach for barcoded mutagenesis that should enable functional genomics in diverse fungi.

scholarly journals Synthesis of fatty acids in the perfused mouse liver

1974 ◽  
Vol 142 (3) ◽  
pp. 611-618 ◽  
Author(s):  
D. Michael W. Salmon ◽  
Neil L. Bowen ◽  
Douglas A. Hems
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
De Novo ◽  
Saturated Fatty Acids ◽  
Carbon Sources ◽  
Acid Synthesis ◽  
Hepatic Glycogen ◽  
Total Rate ◽  
Glucose Carbon

1. Fatty acid synthesis de novo was measured in the perfused liver of fed mice. 2. The total rate, measured by the incorporation into fatty acid of3H from3H2O (1–7μmol of fatty acid/h per g of fresh liver), resembled the rate found in the liver of intact mice. 3. Perfusions with l-[U-14C]lactic acid and [U-14C]glucose showed that circulating glucose at concentrations less than about 17mm was not a major carbon source for newly synthesized fatty acid, whereas lactate (10mm) markedly stimulated fatty acid synthesis, and contributed extensive carbon to lipogenesis. 4. The identification of 50% of the carbon converted into newly synthesized fatty acid lends further credibility to the use of3H2O to measure hepatic fatty acid synthesis. 5. The total rate of fatty acid synthesis, and the contribution of glucose carbon to lipogenesis, were directly proportional to the initial hepatic glycogen concentration. 6. The proportion of total newly synthesized lipid that was released into the perfusion medium was 12–16%. 7. The major products of lipogenesis were saturated fatty acids in triglyceride and phospholipid. 8. The rate of cholesterol synthesis, also measured with3H2O, expressed as acetyl residues consumed, was about one-fourth of the basal rate of fatty acid synthesis. 9. These results are discussed in terms of the carbon sources of hepatic newly synthesized fatty acids, and the effect of glucose, glycogen and lactate in stimulating lipogenesis, independently of their role as precursors.

scholarly journals Effect of Pyruvate Carboxylase Overexpression on the Physiology of Corynebacterium glutamicum

2002 ◽  
Vol 68 (11) ◽  
pp. 5422-5428 ◽  
Author(s):  
Mattheos A. G. Koffas ◽  
Gyoo Yeol Jung ◽  
Juan C. Aon ◽  
Gregory Stephanopoulos
Keyword(s):  
Corynebacterium Glutamicum ◽  
Pyruvate Carboxylase ◽  
Carbon Sources ◽  
Acid Synthesis ◽  
Aspartate Kinase ◽  
Growth Enhancement ◽  
Lysine Production ◽  
Carboxylase Activity ◽  
Amino Acid Synthesis ◽  
Permeabilized Cells

ABSTRACT Pyruvate carboxylase was recently sequenced in Corynebacterium glutamicum and shown to play an important role of anaplerosis in the central carbon metabolism and amino acid synthesis of these bacteria. In this study we investigate the effect of the overexpression of the gene for pyruvate carboxylase (pyc) on the physiology of C. glutamicum ATCC 21253 and ATCC 21799 grown on defined media with two different carbon sources, glucose and lactate. In general, the physiological effects of pyc overexpression in Corynebacteria depend on the genetic background of the particular strain studied and are determined to a large extent by the interplay between pyruvate carboxylase and aspartate kinase activities. If the pyruvate carboxylase activity is not properly matched by the aspartate kinase activity, pyc overexpression results in growth enhancement instead of greater lysine production, despite its central role in anaplerosis and aspartic acid biosynthesis. Aspartate kinase regulation by lysine and threonine, pyruvate carboxylase inhibition by aspartate (shown in this study using permeabilized cells), as well as well-established activation of pyruvate carboxylase by lactate and acetyl coenzyme A are the key factors in determining the effect of pyc overexpression on Corynebacteria physiology.

scholarly journals Heterologous Expression of Two Malate Transporters From an Oleaginous Fungus Mucor circinelloides Improved the Lipid Accumulation in Mucor lusitanicus

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiuwen Wang ◽  
Hassan Mohamed ◽  
Yonghong Bao ◽  
Chen Wu ◽  
Wenyue Shi ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Accumulation ◽  
Carbon Sources ◽  
Reducing Power ◽  
Acid Synthesis ◽  
Mucor Circinelloides ◽  
Microbial Lipids ◽  
Intracellular Lipid ◽  
Engineering Technology ◽  
Oleaginous Fungus

The fungus, Mucor lusitanicus, is of great interest for microbial lipids, because of its ability to accumulate intracellular lipid using various carbon sources. The biosynthesis of fatty acid requires the reducing power NADPH, and acetyl-CoA, which is produced by the cleavage of citrate in cytosol. In this study, we employed different strategies to increase lipid accumulation in the low lipid-producing fungi via metabolic engineering technology. Hence, we constructed the engineered strain of M. lusitanicus CBS 277.49 by using malate transporter (mt) and 2-oxoglutarate: malate antiporter (sodit) from M. circinelloides WJ11. In comparison with the control strain, the lipid content of the overexpressed strains of mt and sodit genes were increased by 24.6 and 33.8%, respectively. These results showed that mt and sodit can affect the distribution of malate in mitochondria and cytosol, provide the substrates for the synthesis of citrate in the mitochondria, and accelerate the transfer of citrate from mitochondria to cytosol, which could play a significant regulatory role in fatty acid synthesis leading to lipids over accumulation.

EFFECTS OF HIGH LEVELS OF DIETARY COPPER ON ENDOGENOUS LIPID METABOLISM IN THE PIG

1972 ◽  
Vol 52 (1) ◽  
pp. 113-123 ◽  
Author(s):  
A. W. MYRES ◽  
J. P. BOWLAND
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Unsaturated Fatty Acids ◽  
Acid Synthesis ◽  
Dietary Copper ◽  
Plasma Triglycerides ◽  
Plasma Fraction ◽  
Endogenous Lipid

Two experiments were carried out to study the effects of dietary copper on the performance and lipid metabolism of pigs. In experiment 1 the addition of 250 ppm copper had no significant effect on performance but resulted in a more unsaturated depot fat. It was postulated that the latter effect could be caused by a preferential mobilization of saturated fatty acid (SFA) from adipose tissue, but examination of the fasting free fatty acid (FFA) plasma fraction revealed no evidence for any preferential mobilization, although the concentration of total FFA was increased in the copper-fed animals. The objective of experiment 2 was to investigate whether dietary copper resulted in an increased synthesis of unsaturated fatty acids (UFA) in adipose tissue. Uptake of plasma triglycerides was prevented by prior injection of Triton WR-1339 to give an uncomplicated picture of fatty acid synthesis. The results showed that copper did alter the distribution of 14C activity in adipose tissue fatty acids but shifted the pattern to one of a more saturated nature, which clearly invalidated the hypothesis that copper increases synthesis of UFA.

scholarly journals Author response: Functional genomics of lipid metabolism in the oleaginous yeast Rhodosporidium toruloides

2018 ◽  
Author(s):  
Samuel T Coradetti ◽  
Dominic Pinel ◽  
Gina M Geiselman ◽  
Masakazu Ito ◽  
Stephen J Mondo ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Functional Genomics ◽  
Oleaginous Yeast ◽  
Rhodosporidium Toruloides ◽  
Author Response
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