Fatty Acids from Microalgae: Targeting the Accumulation of Triacylglycerides

Bilbao, P.; Salvador, Gabriela Alejandra; Leonardi, Patricia I.

doi:10.5772/67482

Cited by 11 publications

(8 citation statements)

References 119 publications

(147 reference statements)

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“…ER-localized GPAT enzymes are reported to be subjected to transcriptional, post-transcriptional and post-translational regulation [25,28,31]. To overcome the possibility of negative endogenous regulation, we decided to test heterologous expression of a GPAT gene (AoGPAT) from the oleaginous green microalga A. obliquus.…”

Section: Design Of Gpat Expression Constructsmentioning

confidence: 99%

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Expression of glycerol-3-phosphate acyltransferase increases neutral lipid accumulation in Nannochloropsis oceanica

Südfeld

Kiyani

Wefelmeier

et al. 2022

Preprint

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Microalgae are considered a suitable production platform for high-value lipids and oleochemicals. Several species including Nannochloropsis oceanica produce large amounts of essential $\omega$-3 polyunsaturated fatty acids (PUFAs) which are integral components of food and feed and have been associated with health-promoting effects. N. oceanica can further accumulate high contents of neutral lipids with chemical properties that render them a potential replacement for plant oils such as palm oil. However, biomass and lipid productivities obtained with microalgae need to be improved to reach commercial feasibility. Genetic engineering can improve biomass and lipid productivities, for instance by increasing carbon flux to lipids. Here, we report the overexpression of two glycerol-3-phosphate acyltransferases (GPAT) in N. oceanica during favorable growth conditions as a strategy to increase neutral lipid content. Transformants overproducing either an endogenous (NoGPAT) or a heterologous (AoGPAT) GPAT enzyme targeted to the endoplasmic reticulum, had up to 42% and 51% increased neutral lipid contents, respectively, compared to the wild type. Biomass productivities of transformant strains were not substantially impaired, resulting in lipid productivities that were increased by up to 37% and 42% for NoGPAT and AoGPAT transformants, respectively. When exposed to nutrient stress, transformants and wild type had similar lipid contents, suggesting that GPAT enzyme availability is a rate-limiting factor for lipid synthesis in N. oceanica under favorable growth conditions. NoGPAT transformants further accumulated PUFAs in neutral lipids, reaching a total of 6.8% PUFAs per biomass, an increase of 24% relative to the wild type. Overall, our results indicate that GPAT is an interesting target for engineering of lipid metabolism in microalgae, in order to improve neutral lipid and PUFA accumulation in microalgae.

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Section: Design Of Gpat Expression Constructsmentioning

confidence: 99%

“…Despite this, the role of GPAT in lipid metabolism of Nannochloropsis, has so far been neglected. As GPAT catalyzes the rst committed and potentially rate-limiting step of the Kennedy pathway [25], this enzyme may be a suitable target for genetically engineering Nannochloropsis strains with improved lipid content and productivity.…”

Section: Introductionmentioning

confidence: 99%

Expression of glycerol-3-phosphate acyltransferase increases neutral lipid accumulation in Nannochloropsis oceanica

Südfeld

Kiyani

Wefelmeier

et al. 2022

Preprint

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show abstract

“…S8). In general, the first step of fatty acid biosynthesis is performed by acetyl-CoA carboxylase complex which catalyses the irreversible carboxylation of acetyl-CoA to produce malonyl-CoA (Bilbao et al 2017). The downregulated gene AccB for acetyl-CoA carboxylase biotin carboxyl carrier protein would cause a decline in fatty acid biosynthesis.…”

Section: Antibiotics Regulated Fatty Acid Biosynthesis and Degradationmentioning

confidence: 99%

Gene expression concerning fatty acid and amino acid metabolism in Chlorella vulgaris cultured with antibiotics

Wang

Sheng

2020

Appl Microbiol Biotechnol

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The green alga Chlorella vulgaris has potential as a source of clean bioenergy with abundant metabolites and a high oil content, and antibiotics are often applied to remove bacteria from culture to obtain axenic algal strains. In this work, ceftazidime and gentamicin sulphate (GS) were added separately and in combination in the aseptic processing of C. vulgaris, and gene expression and metabolites were evaluated. The results showed that ceftazidime and GS effectively inhibited the proliferation of Cyanobacteria and Bacteroidetes, respectively. Overall, the effects of antibiotics on C. vulgaris differed: GS increased the algal concentration, whereas ceftazidime alone and in combination with GS treatment decreased the specific algal growth rate. Based on comparative transcription analysis, 5917 and 5899 differentially expressed genes (DEGs) were respectively upregulated and downregulated by ceftazidime, 963 and 3921 DEGs by GS, and 4532 and 1675 DEGs by the ceftazidime and GS combination. Pathway enrichment analysis showed that the downregulated DEGs in the ceftazidime groups were enriched in the fatty acid biosynthesis pathway but that the upregulated DEGs in the GS group were enriched in the fatty acid degradation pathway. Some pathways related to amino acid metabolism were markably influenced by antibiotic treatment. The results further indicated that antibiotics affected the intracellular concentration of fatty acids and amino acids in C. vulgaris. This study provides a new viewpoint regarding the response of C. vulgaris to antibiotics in the process of obtaining axenic algal strains. Key Points• Ceftazidime and gentamicin sulphate influenced bacterial proliferation.• Downregulated differentially expressed genes mapped to the fatty acid biosynthesis pathway.• Antibiotics affected intracellular concentrations of fatty acids and amino acids.

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“…Despite this, the role of GPAT in lipid metabolism of Nannochloropsis, has so far been neglected. As GPAT catalyzes the first committed and potentially rate-determining step of the Kennedy pathway [26], this enzyme may be a suitable target for genetically engineering Nannochloropsis strains with improved lipid content and productivity.…”

Section: Introductionmentioning

confidence: 99%

Expression of glycerol-3-phosphate acyltransferase increases non-polar lipid accumulation in Nannochloropsis oceanica

et al. 2023

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Microalgae are considered a suitable production platform for high-value lipids and oleochemicals. Several species including Nannochloropsis oceanica produce large amounts of essential $$\omega$$ ω -3 polyunsaturated fatty acids (PUFAs) which are integral components of food and feed and have been associated with health-promoting effects. N. oceanica can further accumulate high contents of non-polar lipids with chemical properties that render them a potential replacement for plant oils such as palm oil. However, biomass and lipid productivities obtained with microalgae need to be improved to reach commercial feasibility. Genetic engineering can improve biomass and lipid productivities, for instance by increasing carbon flux to lipids. Here, we report the overexpression of glycerol-3-phosphate acyltransferase (GPAT) in N. oceanica during favorable growth conditions as a strategy to increase non-polar lipid content. Transformants overproducing either an endogenous (NoGPAT) or a heterologous (Acutodesmus obliquus GPAT) GPAT enzyme targeted to the endoplasmic reticulum had up to 42% and 51% increased non-polar lipid contents, respectively, compared to the wild type. Biomass productivities of transformant strains were not substantially impaired, resulting in lipid productivities that were increased by up to 37% and 42% for NoGPAT and AoGPAT transformants, respectively. When exposed to nutrient stress, transformants and wild type had similar lipid contents, suggesting that GPAT enzyme exerts strong flux control on lipid synthesis in N. oceanica under favorable growth conditions. NoGPAT transformants further accumulated PUFAs in non-polar lipids, reaching a total of 6.8% PUFAs per biomass, an increase of 24% relative to the wild type. Overall, our results indicate that GPAT is an interesting target for engineering of lipid metabolism in microalgae, in order to improve non-polar lipid and PUFAs accumulation in microalgae.

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Fatty Acids from Microalgae: Targeting the Accumulation of Triacylglycerides

Cited by 11 publications

References 119 publications

Expression of glycerol-3-phosphate acyltransferase increases neutral lipid accumulation in Nannochloropsis oceanica

Expression of glycerol-3-phosphate acyltransferase increases neutral lipid accumulation in Nannochloropsis oceanica

Gene expression concerning fatty acid and amino acid metabolism in Chlorella vulgaris cultured with antibiotics

Expression of glycerol-3-phosphate acyltransferase increases non-polar lipid accumulation in Nannochloropsis oceanica

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