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Wei Chen - One of the best experts on this subject based on the ideXlab platform.
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evaluation of metabolome sample preparation and extraction methodologies for Oleaginous filamentous Fungi mortierella alpina
Metabolomics, 2019Co-Authors: Haiqin Chen, Hao Zhang, Xin Tang, Yong Q. Chen, Qin Yang, Wei ChenAbstract:Metabolomics has been successfully applied to guide the rational engineering of industrial strains and improve the performance of bioprocesses. Mortierella alpina has traditionally been one of the most popular industrial strains for the production of polyunsaturated fatty acids. However, a systematic comparison and optimisation of the metabolomic analysis methods of M. alpina has not yet been reported. We sought to identify potential weaknesses that are important for accurate metabolomic analysis. We also aimed to determine an efficient sample preparation protocol for metabolomics studies in the Oleaginous filamentous fungus M. alpina. In this study, using GC-MS, we evaluated three sample preparation protocols and five solvent mixtures by assessment of the metabolite profile differences, the sum of peak intensities and the reproducibility of metabolite quantification. The freeze-dried biomass had better reproducibility and recovery than fresh biomass for metabolite extraction and data normalisation that is part of a metabolomics analysis of filamentous Fungi M. alpina. Methanol:water (1:1) was superior for the profiling of metabolites in Oleaginous Fungi M. alpina. The unbiased metabolite profiling difference between the growth phase and lipids synthesis phase revealed that the degradation of amino acids were critical nodes for the efficient synthesis of lipids in M. alpina. The use of freeze-dried biomass for metabolite extraction and data normalisation was more efficient at measuring the active state of the intracellular metabolites in M. alpina. We recommend extracting the intracellular metabolites with methanol:water (1:1). An important role of amino acid oxidation in the nitrogen limitation-mediated lipid accumulation was found.
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Comparative Proteome Analysis between High Lipid-Producing Strain Mucor circinelloides WJ11 and Low Lipid-Producing Strain CBS 277.49
Journal of agricultural and food chemistry, 2017Co-Authors: Xin Tang, Yuanda Song, Haiqin Chen, Hao Zhang, Yong Q. Chen, Wei ChenAbstract:Mucor circinelloides is one of few Oleaginous Fungi that produces a useful oil rich in γ-linolenic acid, but it usually only produces
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Comparative Proteome Analysis between High Lipid-Producing Strain Mucor circinelloides WJ11 and Low Lipid-Producing Strain CBS 277.49
2017Co-Authors: Xin Tang, Yuanda Song, Haiqin Chen, Hao Zhang, Yong Q. Chen, Wei ChenAbstract:Mucor circinelloides is one of few Oleaginous Fungi that produces a useful oil rich in γ-linolenic acid, but it usually only produces
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Role of malate transporter in lipid accumulation of Oleaginous fungus Mucor circinelloides.
Applied microbiology and biotechnology, 2015Co-Authors: Lina Zhao, Yuanda Song, Haiqin Chen, Wei Chen, Xin Tang, Yong Q. Chen, José T. Cánovas-márquez, Victoriano Garre, Colin RatledgeAbstract:Fatty acid biosynthesis in Oleaginous Fungi requires the supply of reducing power, NADPH, and the precursor of fatty acids, acetyl-CoA, which is generated in the cytosol being produced by ATP: citrate lyase which requires citrate to be, transported from the mitochondrion by the citrate/malate/pyruvate transporter. This transporter, which is within the mitochondrial membrane, transports cytosolic malate into the mitochondrion in exchange for mitochondrial citrate moving into the cytosol (Fig. 1). The role of malate transporter in lipid accumulation in Oleaginous Fungi is not fully understood, however. Therefore, the expression level of the mt gene, coding for a malate transporter, was manipulated in the Oleaginous fungus Mucor circinelloides to analyze its effect on lipid accumulation. The results showed that mt overexpression increased the lipid content for about 70 % (from 13 to 22 % dry cell weight, CDW), whereas the lipid content in mt knockout mutant decreased about 27 % (from 13 to 9.5 % CDW) compared with the control strain. Furthermore, the extracellular malate concentration was decreased in the mt overexpressing strain and increased in the mt knockout strain compared with the wild-type strain. This work suggests that the malate transporter plays an important role in regulating lipid accumulation in Oleaginous fungus M. circinelloides.
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Identification of a critical determinant that enables efficient fatty acid synthesis in Oleaginous Fungi
Scientific reports, 2015Co-Authors: Haiqin Chen, Lei Wang, Hao Zhang, Wei Chen, Hongchao Wang, Guangfei Hao, Liming Liu, Yong Q. ChenAbstract:Microorganisms are valuable resources for lipid production. What makes one microbe but not the other able to efficiently synthesize and accumulate lipids is poorly understood. In the present study, global gene expression prior to and after the onset of lipogenesis was determined by transcriptomics using the Oleaginous fungus Mortierella alpina as a model system. A core of 23 lipogenesis associated genes was identified and their expression patterns shared a high similarity among Oleaginous microbes Chlamydomonas reinhardtii, Mucor circinelloides and Rhizopus oryzae but was dissimilar to the non-Oleaginous Aspergillus nidulans. Unexpectedly, Glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (PGD) in the pentose phosphate pathway (PPP) were found to be the NADPH producers responding to lipogenesis in the Oleaginous microbes. Their role in lipogenesis was confirmed by a knockdown experiment. Our results demonstrate, for the first time, that the PPP plays a significant role during fungal lipogenesis. Up-regulation of NADPH production by the PPP, especially G6PD, may be one of the critical determinants that enables efficiently fatty acid synthesis in Oleaginous microbes.
Haiqin Chen - One of the best experts on this subject based on the ideXlab platform.
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evaluation of metabolome sample preparation and extraction methodologies for Oleaginous filamentous Fungi mortierella alpina
Metabolomics, 2019Co-Authors: Haiqin Chen, Hao Zhang, Xin Tang, Yong Q. Chen, Qin Yang, Wei ChenAbstract:Metabolomics has been successfully applied to guide the rational engineering of industrial strains and improve the performance of bioprocesses. Mortierella alpina has traditionally been one of the most popular industrial strains for the production of polyunsaturated fatty acids. However, a systematic comparison and optimisation of the metabolomic analysis methods of M. alpina has not yet been reported. We sought to identify potential weaknesses that are important for accurate metabolomic analysis. We also aimed to determine an efficient sample preparation protocol for metabolomics studies in the Oleaginous filamentous fungus M. alpina. In this study, using GC-MS, we evaluated three sample preparation protocols and five solvent mixtures by assessment of the metabolite profile differences, the sum of peak intensities and the reproducibility of metabolite quantification. The freeze-dried biomass had better reproducibility and recovery than fresh biomass for metabolite extraction and data normalisation that is part of a metabolomics analysis of filamentous Fungi M. alpina. Methanol:water (1:1) was superior for the profiling of metabolites in Oleaginous Fungi M. alpina. The unbiased metabolite profiling difference between the growth phase and lipids synthesis phase revealed that the degradation of amino acids were critical nodes for the efficient synthesis of lipids in M. alpina. The use of freeze-dried biomass for metabolite extraction and data normalisation was more efficient at measuring the active state of the intracellular metabolites in M. alpina. We recommend extracting the intracellular metabolites with methanol:water (1:1). An important role of amino acid oxidation in the nitrogen limitation-mediated lipid accumulation was found.
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Comparative Proteome Analysis between High Lipid-Producing Strain Mucor circinelloides WJ11 and Low Lipid-Producing Strain CBS 277.49
Journal of agricultural and food chemistry, 2017Co-Authors: Xin Tang, Yuanda Song, Haiqin Chen, Hao Zhang, Yong Q. Chen, Wei ChenAbstract:Mucor circinelloides is one of few Oleaginous Fungi that produces a useful oil rich in γ-linolenic acid, but it usually only produces
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Comparative Proteome Analysis between High Lipid-Producing Strain Mucor circinelloides WJ11 and Low Lipid-Producing Strain CBS 277.49
2017Co-Authors: Xin Tang, Yuanda Song, Haiqin Chen, Hao Zhang, Yong Q. Chen, Wei ChenAbstract:Mucor circinelloides is one of few Oleaginous Fungi that produces a useful oil rich in γ-linolenic acid, but it usually only produces
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Role of malate transporter in lipid accumulation of Oleaginous fungus Mucor circinelloides.
Applied microbiology and biotechnology, 2015Co-Authors: Lina Zhao, Yuanda Song, Haiqin Chen, Wei Chen, Xin Tang, Yong Q. Chen, José T. Cánovas-márquez, Victoriano Garre, Colin RatledgeAbstract:Fatty acid biosynthesis in Oleaginous Fungi requires the supply of reducing power, NADPH, and the precursor of fatty acids, acetyl-CoA, which is generated in the cytosol being produced by ATP: citrate lyase which requires citrate to be, transported from the mitochondrion by the citrate/malate/pyruvate transporter. This transporter, which is within the mitochondrial membrane, transports cytosolic malate into the mitochondrion in exchange for mitochondrial citrate moving into the cytosol (Fig. 1). The role of malate transporter in lipid accumulation in Oleaginous Fungi is not fully understood, however. Therefore, the expression level of the mt gene, coding for a malate transporter, was manipulated in the Oleaginous fungus Mucor circinelloides to analyze its effect on lipid accumulation. The results showed that mt overexpression increased the lipid content for about 70 % (from 13 to 22 % dry cell weight, CDW), whereas the lipid content in mt knockout mutant decreased about 27 % (from 13 to 9.5 % CDW) compared with the control strain. Furthermore, the extracellular malate concentration was decreased in the mt overexpressing strain and increased in the mt knockout strain compared with the wild-type strain. This work suggests that the malate transporter plays an important role in regulating lipid accumulation in Oleaginous fungus M. circinelloides.
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Identification of a critical determinant that enables efficient fatty acid synthesis in Oleaginous Fungi
Scientific reports, 2015Co-Authors: Haiqin Chen, Lei Wang, Hao Zhang, Wei Chen, Hongchao Wang, Guangfei Hao, Liming Liu, Yong Q. ChenAbstract:Microorganisms are valuable resources for lipid production. What makes one microbe but not the other able to efficiently synthesize and accumulate lipids is poorly understood. In the present study, global gene expression prior to and after the onset of lipogenesis was determined by transcriptomics using the Oleaginous fungus Mortierella alpina as a model system. A core of 23 lipogenesis associated genes was identified and their expression patterns shared a high similarity among Oleaginous microbes Chlamydomonas reinhardtii, Mucor circinelloides and Rhizopus oryzae but was dissimilar to the non-Oleaginous Aspergillus nidulans. Unexpectedly, Glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (PGD) in the pentose phosphate pathway (PPP) were found to be the NADPH producers responding to lipogenesis in the Oleaginous microbes. Their role in lipogenesis was confirmed by a knockdown experiment. Our results demonstrate, for the first time, that the PPP plays a significant role during fungal lipogenesis. Up-regulation of NADPH production by the PPP, especially G6PD, may be one of the critical determinants that enables efficiently fatty acid synthesis in Oleaginous microbes.
Yuanda Song - One of the best experts on this subject based on the ideXlab platform.
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Increased Lipid Accumulation in Mucor circinelloides by Overexpression of Mitochondrial Citrate Transporter Genes
2019Co-Authors: Junhuan Yang, Victoriano Garre, Md. Ahsanul Kabir Khan, Wanwipa Vongsangnak, Yuanda SongAbstract:Mucor circinelloides has been commonly used as the model microbe to investigate lipid production as an Oleaginous fungus. Mitochondrial citrate transporter can catalyze the translocation of the citrate, accumulated from TCA cycle, across the mitochondrial inner membrane. The extra-mitochondrial citrate is then cleaved by ATP-citrate lyase to oxaloacetate (OAA) and acetyl-CoA. Acetyl-CoA together with NADPH generated in cytosol is used for fatty acid biosynthesis. Thus, citrate transporters provide a link between TCA cycle in mitochondria and fatty acid biosynthesis in cytosol. However, the role of citrate transporters for lipid accumulation in Oleaginous Fungi is not clear. Two genes coding for citrate transporters, named citrate transporter (ct) and tricarboxylate transporter (tct) respectively, were present in the genome of Oleaginous fungus M. circinelloides WJ11, a high lipid producing strain (36%, lipid/cell dry weight). As the mutant of strain CBS 277.49 (15%, lipid/cell dry weight) has been constructed and its genetic engineering tools are available for gene manipulation, so in this work, we investigated the role of citrate transporters in regulating lipid biosynthesis by overexpressing the citrate transporters of M. circinelloides WJ11 in CBS 277.49. Results: Our results showed that overexpression of ct and tct led to increased lipid accumulation by 44% (from 13.0% to 18.8%, w/w, CDW) and 68% (from 13.0% to 21.8%, w/w, CDW), respectively. Moreover, extracellular citrate concentration in ct-overexpressing strains (4.91 mM) and tct-overexpressing (3.25 mM) were significantly decreased by 20% and 47% respectively compared to the control (6.09 mM). Furthermore, overexpression of the citrate transporter genes activated the downstream steps in lipid biosynthesis, such as ATP citrate lyase (acl gene) and fatty acid synthases (fas1 and fas2 genes), indicating a greater flux of carbon went into fatty acid biosynthesis. Conclusions: This is the first report showing that citrate transporters involved in lipid accumulation in M. circinelloides. Both citrate transporter and tricarboxylate transporter could transport mitochondrial citrate to cytoplasm, which could provide more citrate to be cleaved by increased ACL to provide more acetyl-CoA and NADPH for increased FAS to synthesize fatty acids, thus, play a vital role in lipid biosynthesis in Oleaginous fungus M. circinelloides.
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Characteristics of cell growth and lipid accumulation of high and low lipid-producing strains of Mucor circinelloides grown on different glucose-oil mixed media
Process Biochemistry, 2018Co-Authors: Xinyi Zan, Xin Tang, Linfang Chu, Yuanda SongAbstract:Abstract Mucor circinelloides is one of the few Oleaginous Fungi that produce large amounts of γ-linolenic acid (GLA). However, there are few reports regarding the lipid accumulation characteristics and assimilation preferences of M. circinelloides grown on different oils. The present study investigated the characteristics of cell growth, lipid accumulation, and lipase activity of a low lipid-producing strain M. circinelloides CBS 277.49 and a high lipid-producing strain M. circinelloides WJ11. The highest biomass of 21.2 g/L was obtained for CBS 277.49 grown on soybean oil, while the highest lipid content of 65% was obtained when WJ11 was grown on soybean phospholipids. M. circinelloides preferred to assimilate exogenous palmitic, stearic, and α-linolenic acid to synthesize intracellular triacylglycerols. Soybean phospholipids and phytosterol esters stimulated the production of intracellular lipases in both strains more efficiently than soybean oils. The maximal lipase activity of 2200 U/g protein was observed for CBS 277.49 grown on phytosterol esters, while the maximal lipase activity of 2000 U/g protein was observed for WJ11 grown on soybean phospholipids. Although the transcriptional levels of the lipase genes were sharply upregulated when strains were grown on glucose-oil mixed media, the extracellular lipase activity in the medium was still low at 4–210 U/g protein.
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Improved γ-linolenic acid production in Mucor circinelloides by homologous overexpressing of delta-12 and delta-6 desaturases.
Microbial cell factories, 2017Co-Authors: Yao Zhang, Yuanda Song, Xiao Luan, Victoriano Garre, Huaiyuan Zhang, Colin RatledgeAbstract:γ-Linolenic acid (GLA) is important because of its nutritional value and medicinal applications. Although the biosynthetic pathways of some plant and microbial GLA have been deciphered, current understanding of the correlation between desaturases and GLA synthesis in Oleaginous Fungi is incomplete. In previous work, we found that a large amount of oleic acid (OA) had not been converted to linoleic acid (LA) or GLA in Mucor circinelloides CBS 277.49, which may be due to inadequate activities of the delta-12 or delta-6 desaturases, and thus leading to the accumulation of OA and LA. Thus, it is necessary to explore the main contributing factor during the process of GLA biosynthesis in M. circinelloides. To enhance GLA production in M. circinelloides, homologous overexpression of delta-12 and two delta-6 desaturases (named delta-6-1 and delta-6-2, respectively) were analyzed. When delta-6 desaturase were overexpressed in M. circinelloides, up to 43% GLA was produced in the total fatty acids, and the yield of GLA reached 180 mg/l, which were, respectively, 38 and 33% higher than the control strain. These findings revealed that delta-6 desaturase (especially for delta-6-1 desaturase) plays an important role in GLA synthesis by M. circinelloides. The strain overexpressing delta-6-1 desaturase may have potential application in microbial GLA production.
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Comparative Proteome Analysis between High Lipid-Producing Strain Mucor circinelloides WJ11 and Low Lipid-Producing Strain CBS 277.49
Journal of agricultural and food chemistry, 2017Co-Authors: Xin Tang, Yuanda Song, Haiqin Chen, Hao Zhang, Yong Q. Chen, Wei ChenAbstract:Mucor circinelloides is one of few Oleaginous Fungi that produces a useful oil rich in γ-linolenic acid, but it usually only produces
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Comparative Proteome Analysis between High Lipid-Producing Strain Mucor circinelloides WJ11 and Low Lipid-Producing Strain CBS 277.49
2017Co-Authors: Xin Tang, Yuanda Song, Haiqin Chen, Hao Zhang, Yong Q. Chen, Wei ChenAbstract:Mucor circinelloides is one of few Oleaginous Fungi that produces a useful oil rich in γ-linolenic acid, but it usually only produces
Xin Tang - One of the best experts on this subject based on the ideXlab platform.
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evaluation of metabolome sample preparation and extraction methodologies for Oleaginous filamentous Fungi mortierella alpina
Metabolomics, 2019Co-Authors: Haiqin Chen, Hao Zhang, Xin Tang, Yong Q. Chen, Qin Yang, Wei ChenAbstract:Metabolomics has been successfully applied to guide the rational engineering of industrial strains and improve the performance of bioprocesses. Mortierella alpina has traditionally been one of the most popular industrial strains for the production of polyunsaturated fatty acids. However, a systematic comparison and optimisation of the metabolomic analysis methods of M. alpina has not yet been reported. We sought to identify potential weaknesses that are important for accurate metabolomic analysis. We also aimed to determine an efficient sample preparation protocol for metabolomics studies in the Oleaginous filamentous fungus M. alpina. In this study, using GC-MS, we evaluated three sample preparation protocols and five solvent mixtures by assessment of the metabolite profile differences, the sum of peak intensities and the reproducibility of metabolite quantification. The freeze-dried biomass had better reproducibility and recovery than fresh biomass for metabolite extraction and data normalisation that is part of a metabolomics analysis of filamentous Fungi M. alpina. Methanol:water (1:1) was superior for the profiling of metabolites in Oleaginous Fungi M. alpina. The unbiased metabolite profiling difference between the growth phase and lipids synthesis phase revealed that the degradation of amino acids were critical nodes for the efficient synthesis of lipids in M. alpina. The use of freeze-dried biomass for metabolite extraction and data normalisation was more efficient at measuring the active state of the intracellular metabolites in M. alpina. We recommend extracting the intracellular metabolites with methanol:water (1:1). An important role of amino acid oxidation in the nitrogen limitation-mediated lipid accumulation was found.
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Characteristics of cell growth and lipid accumulation of high and low lipid-producing strains of Mucor circinelloides grown on different glucose-oil mixed media
Process Biochemistry, 2018Co-Authors: Xinyi Zan, Xin Tang, Linfang Chu, Yuanda SongAbstract:Abstract Mucor circinelloides is one of the few Oleaginous Fungi that produce large amounts of γ-linolenic acid (GLA). However, there are few reports regarding the lipid accumulation characteristics and assimilation preferences of M. circinelloides grown on different oils. The present study investigated the characteristics of cell growth, lipid accumulation, and lipase activity of a low lipid-producing strain M. circinelloides CBS 277.49 and a high lipid-producing strain M. circinelloides WJ11. The highest biomass of 21.2 g/L was obtained for CBS 277.49 grown on soybean oil, while the highest lipid content of 65% was obtained when WJ11 was grown on soybean phospholipids. M. circinelloides preferred to assimilate exogenous palmitic, stearic, and α-linolenic acid to synthesize intracellular triacylglycerols. Soybean phospholipids and phytosterol esters stimulated the production of intracellular lipases in both strains more efficiently than soybean oils. The maximal lipase activity of 2200 U/g protein was observed for CBS 277.49 grown on phytosterol esters, while the maximal lipase activity of 2000 U/g protein was observed for WJ11 grown on soybean phospholipids. Although the transcriptional levels of the lipase genes were sharply upregulated when strains were grown on glucose-oil mixed media, the extracellular lipase activity in the medium was still low at 4–210 U/g protein.
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Comparative Proteome Analysis between High Lipid-Producing Strain Mucor circinelloides WJ11 and Low Lipid-Producing Strain CBS 277.49
Journal of agricultural and food chemistry, 2017Co-Authors: Xin Tang, Yuanda Song, Haiqin Chen, Hao Zhang, Yong Q. Chen, Wei ChenAbstract:Mucor circinelloides is one of few Oleaginous Fungi that produces a useful oil rich in γ-linolenic acid, but it usually only produces
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Comparative Proteome Analysis between High Lipid-Producing Strain Mucor circinelloides WJ11 and Low Lipid-Producing Strain CBS 277.49
2017Co-Authors: Xin Tang, Yuanda Song, Haiqin Chen, Hao Zhang, Yong Q. Chen, Wei ChenAbstract:Mucor circinelloides is one of few Oleaginous Fungi that produces a useful oil rich in γ-linolenic acid, but it usually only produces
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Role of malate transporter in lipid accumulation of Oleaginous fungus Mucor circinelloides.
Applied microbiology and biotechnology, 2015Co-Authors: Lina Zhao, Yuanda Song, Haiqin Chen, Wei Chen, Xin Tang, Yong Q. Chen, José T. Cánovas-márquez, Victoriano Garre, Colin RatledgeAbstract:Fatty acid biosynthesis in Oleaginous Fungi requires the supply of reducing power, NADPH, and the precursor of fatty acids, acetyl-CoA, which is generated in the cytosol being produced by ATP: citrate lyase which requires citrate to be, transported from the mitochondrion by the citrate/malate/pyruvate transporter. This transporter, which is within the mitochondrial membrane, transports cytosolic malate into the mitochondrion in exchange for mitochondrial citrate moving into the cytosol (Fig. 1). The role of malate transporter in lipid accumulation in Oleaginous Fungi is not fully understood, however. Therefore, the expression level of the mt gene, coding for a malate transporter, was manipulated in the Oleaginous fungus Mucor circinelloides to analyze its effect on lipid accumulation. The results showed that mt overexpression increased the lipid content for about 70 % (from 13 to 22 % dry cell weight, CDW), whereas the lipid content in mt knockout mutant decreased about 27 % (from 13 to 9.5 % CDW) compared with the control strain. Furthermore, the extracellular malate concentration was decreased in the mt overexpressing strain and increased in the mt knockout strain compared with the wild-type strain. This work suggests that the malate transporter plays an important role in regulating lipid accumulation in Oleaginous fungus M. circinelloides.
Yong Q. Chen - One of the best experts on this subject based on the ideXlab platform.
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evaluation of metabolome sample preparation and extraction methodologies for Oleaginous filamentous Fungi mortierella alpina
Metabolomics, 2019Co-Authors: Haiqin Chen, Hao Zhang, Xin Tang, Yong Q. Chen, Qin Yang, Wei ChenAbstract:Metabolomics has been successfully applied to guide the rational engineering of industrial strains and improve the performance of bioprocesses. Mortierella alpina has traditionally been one of the most popular industrial strains for the production of polyunsaturated fatty acids. However, a systematic comparison and optimisation of the metabolomic analysis methods of M. alpina has not yet been reported. We sought to identify potential weaknesses that are important for accurate metabolomic analysis. We also aimed to determine an efficient sample preparation protocol for metabolomics studies in the Oleaginous filamentous fungus M. alpina. In this study, using GC-MS, we evaluated three sample preparation protocols and five solvent mixtures by assessment of the metabolite profile differences, the sum of peak intensities and the reproducibility of metabolite quantification. The freeze-dried biomass had better reproducibility and recovery than fresh biomass for metabolite extraction and data normalisation that is part of a metabolomics analysis of filamentous Fungi M. alpina. Methanol:water (1:1) was superior for the profiling of metabolites in Oleaginous Fungi M. alpina. The unbiased metabolite profiling difference between the growth phase and lipids synthesis phase revealed that the degradation of amino acids were critical nodes for the efficient synthesis of lipids in M. alpina. The use of freeze-dried biomass for metabolite extraction and data normalisation was more efficient at measuring the active state of the intracellular metabolites in M. alpina. We recommend extracting the intracellular metabolites with methanol:water (1:1). An important role of amino acid oxidation in the nitrogen limitation-mediated lipid accumulation was found.
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Comparative Proteome Analysis between High Lipid-Producing Strain Mucor circinelloides WJ11 and Low Lipid-Producing Strain CBS 277.49
Journal of agricultural and food chemistry, 2017Co-Authors: Xin Tang, Yuanda Song, Haiqin Chen, Hao Zhang, Yong Q. Chen, Wei ChenAbstract:Mucor circinelloides is one of few Oleaginous Fungi that produces a useful oil rich in γ-linolenic acid, but it usually only produces
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Comparative Proteome Analysis between High Lipid-Producing Strain Mucor circinelloides WJ11 and Low Lipid-Producing Strain CBS 277.49
2017Co-Authors: Xin Tang, Yuanda Song, Haiqin Chen, Hao Zhang, Yong Q. Chen, Wei ChenAbstract:Mucor circinelloides is one of few Oleaginous Fungi that produces a useful oil rich in γ-linolenic acid, but it usually only produces
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Role of malate transporter in lipid accumulation of Oleaginous fungus Mucor circinelloides.
Applied microbiology and biotechnology, 2015Co-Authors: Lina Zhao, Yuanda Song, Haiqin Chen, Wei Chen, Xin Tang, Yong Q. Chen, José T. Cánovas-márquez, Victoriano Garre, Colin RatledgeAbstract:Fatty acid biosynthesis in Oleaginous Fungi requires the supply of reducing power, NADPH, and the precursor of fatty acids, acetyl-CoA, which is generated in the cytosol being produced by ATP: citrate lyase which requires citrate to be, transported from the mitochondrion by the citrate/malate/pyruvate transporter. This transporter, which is within the mitochondrial membrane, transports cytosolic malate into the mitochondrion in exchange for mitochondrial citrate moving into the cytosol (Fig. 1). The role of malate transporter in lipid accumulation in Oleaginous Fungi is not fully understood, however. Therefore, the expression level of the mt gene, coding for a malate transporter, was manipulated in the Oleaginous fungus Mucor circinelloides to analyze its effect on lipid accumulation. The results showed that mt overexpression increased the lipid content for about 70 % (from 13 to 22 % dry cell weight, CDW), whereas the lipid content in mt knockout mutant decreased about 27 % (from 13 to 9.5 % CDW) compared with the control strain. Furthermore, the extracellular malate concentration was decreased in the mt overexpressing strain and increased in the mt knockout strain compared with the wild-type strain. This work suggests that the malate transporter plays an important role in regulating lipid accumulation in Oleaginous fungus M. circinelloides.
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Identification of a critical determinant that enables efficient fatty acid synthesis in Oleaginous Fungi
Scientific reports, 2015Co-Authors: Haiqin Chen, Lei Wang, Hao Zhang, Wei Chen, Hongchao Wang, Guangfei Hao, Liming Liu, Yong Q. ChenAbstract:Microorganisms are valuable resources for lipid production. What makes one microbe but not the other able to efficiently synthesize and accumulate lipids is poorly understood. In the present study, global gene expression prior to and after the onset of lipogenesis was determined by transcriptomics using the Oleaginous fungus Mortierella alpina as a model system. A core of 23 lipogenesis associated genes was identified and their expression patterns shared a high similarity among Oleaginous microbes Chlamydomonas reinhardtii, Mucor circinelloides and Rhizopus oryzae but was dissimilar to the non-Oleaginous Aspergillus nidulans. Unexpectedly, Glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (PGD) in the pentose phosphate pathway (PPP) were found to be the NADPH producers responding to lipogenesis in the Oleaginous microbes. Their role in lipogenesis was confirmed by a knockdown experiment. Our results demonstrate, for the first time, that the PPP plays a significant role during fungal lipogenesis. Up-regulation of NADPH production by the PPP, especially G6PD, may be one of the critical determinants that enables efficiently fatty acid synthesis in Oleaginous microbes.
