Safety evaluation of an extension of use of the food enzyme triacylglycerol lipase from the non-genetically modified Aspergillus luchuensis strain AE-L.

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) is produced with the non-genetically modified Aspergillus luchuensis strain AE-L by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in one food manufacturing process. Subsequently, the applicant has requested to extend its use to include four additional processes and to revise the previous use level. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of five food manufacturing processes. The dietary exposure to the food enzyme-total organic solids (TOS) was calculated to be up to 0.458 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level previously reported (1726 mg TOS/kg bw per day, the highest dose tested), the Panel derived a revised margin of exposure of at least 3769. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.

Dynamical modelling of lipid droplet formation suggests a key function of membrane phospholipids.

Cells store triacylglycerol (TAG) within lipid droplets (LDs). A dynamic model describing complete LD formation at the endoplasmic reticulum (ER) membrane does not yet exist. A biochemical-biophysical model of LD synthesis is proposed. It describes the time-dependent accumulation of TAG in the ER membrane as the formation of a potential LD (pLD) bounded by spherical caps of the inner and outer monolayers of the membrane. The expansion rate of the pLD depends on the TAG supply, the elastic properties of the ER membrane, and the recruitment of phospholipids (PLs) to the cap-covering monolayers. Model simulations provided the following insights: (a) Marginal differences in the surface tension of the cap monolayers are sufficient to fully drive the expansion of the pLD towards the cytosol or lumen. (b) Selective reduction of PL supply to the luminal monolayer ensures stable formation of cytosolic LDs, irrespective of variations in the elasto-mechanical properties of the ER membrane. (c) The rate of TAG supply to the cytosolic monolayer has a major effect on the size and maturation time of LDs but has no significant effect on the TAG export per individual LD. The recruitment of additional PLs to the cap monolayers of pLDs critically controls the budding direction, size, and maturation time of LDs. The ability of cells to acquire additional LD initiation sites appears to be key to coping with acutely high levels of potentially toxic free fatty acids.

Architecture and function of yeast phosphatidate phosphatase Pah1 domains/regions.

Phosphatidate (PA) phosphatase, which catalyzes the Mg2+-dependent dephosphorylation of PA to produce diacylglycerol, provides a direct precursor for the synthesis of the storage lipid triacylglycerol and the membrane phospholipids phosphatidylcholine and phosphatidylethanolamine. The enzyme controlling the key phospholipid PA also plays a crucial role in diverse aspects of lipid metabolism and cell physiology. PA phosphatase is a peripheral membrane enzyme that is composed of multiple domains/regions required for its catalytic function and subcellular localization. In this review, we discuss the domains/regions of PA phosphatase from the yeast Saccharomyces cerevisiae with reference to the homologous enzyme from mammalian cells.

Development of the insect adult fat body relies on glycolysis, lipid synthesis, cell proliferation, and cell adhesion.

The fat body of the holometabolous insect is remodeled by the degradation of the larval fat body and the development of the adult fat body during metamorphosis. However, the mechanism of adult fat body development is quite unclear. Using the agricultural pest Helicoverpa armigera, the cotton bollworm, as a model, we revealed that the development of adult fat body was regulated by glycolysis, triglyceride (triacylglycerol [TAG]) synthesis, cell proliferation, and cell adhesion. RNA sequencing detected a set of genes that were upregulated in the 8-d late pupal fat body at a late metamorphic stage compared with the 2-d pupal fat body at an earlier metamorphic stage. The pathways for glycolysis, TAG synthesis, cell proliferation, and cell adhesion were enriched by the differentially expressed genes, and the key genes linked with these pathways showed increased expression in the 8-d pupal fat body. Knockdown of phosphofructokinase (Pfk), acetyl-CoA carboxylase (Acc1), phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit (P110) and collagen alpha-1(IV) chain (Col4a1) by RNA interference resulted in abnormal eclosion and death at pupal stages, and repressed lipid droplets accumulation and adult fat body development. The expression of Acc1, P110, and Col4a1 was repressed by the insect steroid hormone 20-hydroxyecdysone (20E). The critical genes in the 20E pathway appeared to decrease at the late pupal stage. These data suggested that the development of the insect adult fat body is regulated by glycolysis, lipids synthesis, cell proliferation, and cell adhesion at the late pupal stage when the 20E signal decreases.

Safety evaluation of an extension of use of the food enzyme triacylglycerol lipase from the non-genetically modified Rhizopus arrhizus strain AE-TL(B).

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) is produced with the non-genetically modified Rhizopus arrhizus strain AE-TL(B) by Amano Enzyme Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in two food manufacturing processes. Subsequently, the applicant requested to extend its use to include four additional processes and to revise the use levels. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of six food manufacturing processes. As the food enzyme-total organic solids (TOS) are removed from one food manufacturing process, the dietary exposure to the food enzyme-TOS was estimated only for the remaining five processes. Dietary exposure was calculated to be up to 0.086 mg TOS/kg body weight (bw) per day in European populations. When combined with the no observed adverse effect level reported in the previous opinion (1960 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 22,791. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.

Enhanced triacylglycerol metabolism contributes to the efficient biosynthesis of spinosad in Saccharopolyspora spinosa.

Triacylglycerol (TAG) is crucial for antibiotic biosynthesis derived from Streptomyces, as it serves as an important carbon source. In this study, the supplementation of exogenous TAG led to a 3.92-fold augmentation in spinosad production. The impact of exogenous TAG on the metabolic network of Saccharopolyspora spinosa were deeply analyzed through comparative proteomics. To optimize TAG metabolism and enhance spinosad biosynthesis, the lipase-encoding genes lip886 and lip385 were overexpressed or co-expressed. The results shown that the yield of spinosad was increased by 0.8-fold and 0.4-fold when lip886 and lip385 genes were overexpressed, respectively. Synergistic co-expression of these genes resulted in a 2.29-fold increase in the yield of spinosad. Remarkably, the combined overexpression of lip886 and lip385 in the presence of exogenous TAG elevated spinosad yields by 5.5-fold, led to a drastic increase in spinosad production from 0.036 g/L to 0.234 g/L. This study underscores the modification of intracellular concentrations of free fatty acids (FFAs), short-chain acyl-CoAs, ATP, and NADPH as mechanisms by which exogenous TAG modulates spinosad biosynthesis. Overall, the findings validate the enhancement of TAG catabolism as a beneficial strategy for optimizing spinosad production and provide foundational insights for engineering secondary metabolite biosynthesis pathways in another Streptomyces.

Effects of chain length and saturation of triacylglycerols on the characteristics and gastrointestinal digestion fates of curcumin-loaded triacylglycerol nanoparticles.

This study assessed the effects of fatty acid length and saturation on the physicochemical, thermal, and gastrointestinal digestive characteristics of curcumin-loaded homo-triacylglycerol nanoparticles (C-NPs). All C-NPs had good colloidal stability and efficiently entrapped curcumin, regardless of their length and saturation. Tricaprylin NPs, with shorter chains, had a smaller size and emulsifier surface load. Curcumin was released faster from low-melting C-NPs (tricaprylin and triolein) than those with high-melting-point (trimyristin, tripalmitin, and tristearin); however, both were negligible without lipolysis. None of the C-NPs underwent significant aggregation, coalescence, or breakdown during digestion before the small intestine. Notably, longer and more saturated chains resulted in a slower initial rate and lower degree of lipolysis in the small intestine. However, greater bioaccessibility of curcumin was observed only with longer chains (tricaprylin, 70.72%; trimyristin, 78.05%; tripalmitin, 85.09%; tristearin, 89.65%; triolein, 89.71%). These findings could be valuable for the development of rational curcumin formulations for functional foods.

The Effects of Oleic Acid and Palmitic Acid on Porcine Muscle Satellite Cells.

We aimed to determine the effects of oleic acid (OA) and palmitic acid (PA), alone or in combination, on proliferation, differentiation, triacylglycerol (TAG) content, and gene expression in porcine muscle satellite cells (PMSCs). Results revealed that OA-alone- and PA + OA-treated PMSCs showed significantly increased viability than those in the control or PA-alone-treated groups. No significant effects on apoptosis were observed in all three treatments, whereas necrosis was significantly lower in OA-alone- and PA + OA-treated groups than in the control and PA-alone-treated groups. Myotube formation significantly increased in OA-alone and PA + OA-treated PMSCs than in the control and PA-alone-treated PMSCs. mRNA expression of the myogenesis-related genes MyoD1 and MyoG and of the adipogenesis-related genes PPARα, C/EBPα, PLIN1, FABP4, and FAS was significantly upregulated in OA-alone- and PA + OA-treated cells compared to control and PA-alone-treated cells, consistent with immunoblotting results for MyoD1 and MyoG. Supplementation of unsaturated fatty acid (OA) with/without saturated fatty acid (PA) significantly stimulated TAG accumulation in treated cells compared to the control and PA-alone-treated PMSCs. These results indicate that OA (alone and with PA) promotes proliferation by inhibiting necrosis and promoting myotube formation and TAG accumulation, likely upregulating myogenesis- and adipogenesis-related gene expression by modulating the effects of PA in PMSCs.

Identification and characterization of the suppressed lipid accumulation-related gene, SLA1, in the oleaginous yeast Lipomyces starkeyi.

The oleaginous yeast Lipomyces starkeyi is an attractive industrial yeast that can accumulate high amounts of intracellular lipids. Identification of genes involved in lipid accumulation contributes not only to elucidating the lipid accumulation mechanism but also to breeding industrially useful high lipid-producing strains. In this study, the suppressed lipid accumulation-related gene (SLA1) was identified as the causative gene of the sr22 mutant with decreased lipid productivity. SLA1 mutation reduced gene expression in lipid biosynthesis and increased gene expression in ß-oxidation. Our results suggest that SLA1 mutation may leads to decreased lipid productivity. SLA1 deletion also exhibited decreased gene expression in ß-oxidation and increased lipid accumulation, suggesting that SLA1 deletion is a useful tool to improve lipid accumulation in L. starkeyi for industrialization.

The Biosynthesis Pattern and Transcriptome Analysis of Sapindus saponaria Oil.

The Sapindus saponaria (soapberry) kernel is rich in oil that has antibacterial, anti-inflammatory, and antioxidant properties, promotes cell proliferation, cell migration, and stimulates skin wound-healing effects. S. saponaria oil has excellent lubricating properties and is a high-quality raw material for biodiesel and premium lubricants, showing great potential in industrial and medical applications. Metabolite and transcriptome analysis revealed patterns of oil accumulation and composition and differentially expressed genes (DEGs) during seed development. Morphological observations of soapberry fruits at different developmental stages were conducted, and the oil content and fatty acid composition of the kernels were determined. Transcriptome sequencing was performed on kernels at 70, 100, and 130 days after flowering (DAF). The oil content of soapberry kernels was lowest at 60 DAF (5%) and peaked at 130 DAF (31%). Following soapberry fruit-ripening, the primary fatty acids in the kernels were C18:1 (oleic acid) and C18:3 (linolenic acid), accounting for an average proportion of 62% and 18%, respectively. The average contents of unsaturated fatty acids and saturated fatty acids in the kernel were 86% and 14%, respectively. Through the dynamic changes in fatty acid composition and DEGs analysis of soapberry kernels, FATA, KCR1, ECR, FAD2 and FAD3 were identified as candidate genes contributing to a high proportion of C18:1 and C18:3, while DGAT3 emerged as a key candidate gene for TAG biosynthesis. The combined analysis of transcriptome and metabolism unveiled the molecular mechanism of oil accumulation, leading to the creation of a metabolic pathway pattern diagram for oil biosynthesis in S. saponaria kernels. The study of soapberry fruit development, kernel oil accumulation, and the molecular mechanism of oil biosynthesis holds great significance in increasing oil yield and improving oil quality.

Alternate solvent for soybean oil extraction based on extractability and membrane solvent recovery.

Ethyl acetate, acetone, 2-propanol, 1-propanol, and ethanol were screened among the class 3 category solvents as an alternative to hexane based on operational and occupational safety and bio-renewability potential. All five solvents exhibited higher extractability (22.3 to 23.2%) than hexane (21.5%) with soybean flour. Additionally, there was no significant difference in the fatty acid and triacylglycerol (TAG) composition of the oils extracted using alternate solvents and hexane, indicating the oil quality was not affected. More importantly, ethyl acetate (2.1%) resulted in a marginally higher yield of TAG, while 2-propanol showed a nearly equal yield to hexane. Further, membrane desolventizing was attempted to mitigate the limitations of higher thermal energy requirements. One of the polydimethylsiloxane membranes exhibited good selectivity (TAG rejection 85.8%) and acceptable flux (59.3 L·m-2·h-1) with an ethyl acetate miscella system. Under plant-simulated recirculation conditions, a two-stage membrane process reduced the oil content in permeate to 2.5%. The study revealed that ethyl acetate could potentially replace hexane, considering its higher TAG extractability and suitability for the membrane-augmented solvent recycling process in the extraction plants.

Safety evaluation of the food enzyme triacylglycerol lipase from the non-genetically modified Penicillium caseifulvum strain AE-LRF.

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) is produced with the non-genetically modified Penicillium caseifulvum strain AE-LRF by Amano Enzyme Inc. The food enzyme was free from viable cells of the production organism. It is intended to be used in four food manufacturing processes. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.013 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 69 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 5308. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. However, the Panel noted that traces of ■■■■■, used in the manufacture of the triacylglycerol lipase, may be found in the food enzyme. The Panel considered that the risk of allergic reactions upon dietary exposure could not be excluded, particularly in individuals sensitised to fish. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Protein kinase Hsl1 phosphorylates Pah1 to inhibit phosphatidate phosphatase activity and regulate lipid synthesis in Saccharomyces cerevisiae.

In Saccharomyces cerevisiae, Pah1 phosphatidate (PA) phosphatase, which catalyzes the Mg2+-dependent dephosphorylation of PA to produce diacylglycerol, plays a key role in utilizing PA for the synthesis of the neutral lipid triacylglycerol and thereby controlling the PA-derived membrane phospholipids. The enzyme function is controlled by its subcellular location as regulated by phosphorylation and dephosphorylation. Pah1 is initially inactivated in the cytosol through phosphorylation by multiple protein kinases and then activated via its recruitment and dephosphorylation by the protein phosphatase Nem1-Spo7 at the nuclear/endoplasmic reticulum membrane where the PA phosphatase reaction occurs. Many of the protein kinases that phosphorylate Pah1 have yet to be characterized with the identification of the target residues. Here, we established Pah1 as a bona fide substrate of septin-associated Hsl1, a protein kinase involved in mitotic morphogenesis checkpoint signaling. The Hsl1 activity on Pah1 was dependent on reaction time and the amounts of protein kinase, Pah1, and ATP. The Hsl1 phosphorylation of Pah1 occurred on Ser-748 and Ser-773, and the phosphorylated protein exhibited a 5-fold reduction in PA phosphatase catalytic efficiency. Analysis of cells expressing the S748A and S773A mutant forms of Pah1 indicated that Hsl1-mediated phosphorylation of Pah1 promotes membrane phospholipid synthesis at the expense of triacylglycerol, and ensures the dependence of Pah1 function on the Nem1-Spo7 protein phosphatase. This work advances the understanding of how Hsl1 facilitates membrane phospholipid synthesis through the phosphorylation-mediated regulation of Pah1.

Functional Characterization of the Effects of CsDGAT1 and CsDGAT2 on Fatty Acid Composition in Camelina sativa.

Triacylglycerols (TAGs) are the storage oils of plant seeds, and these lipids provide energy for seed germination and valuable oils for human consumption. Three diacylglycerol acyltransferases (DGAT1, DGAT2, and DGAT3) and phospholipid:diacylglycerol acyltransferases participate in the biosynthesis of TAGs. DGAT1 and DGAT2 participate in the biosynthesis of TAGs through the endoplasmic reticulum (ER) pathway. In this study, we functionally characterized CsDGAT1 and CsDGAT2 from camelina (Camelina sativa). Green fluorescent protein-fused CsDGAT1 and CsDGAT2 localized to the ER when transiently expressed in Nicotiana benthamiana leaves. To generate Csdgat1 and Csdgat2 mutants using the CRISPR/Cas9 system, camelina was transformed with a binary vector carrying Cas9 and the respective guide RNAs targeting CsDGAT1s and CsDGAT2s via the Agrobacterium-mediated floral dip method. The EDD1 lines had missense and nonsense mutations in the CsDGAT1 homoeologs, suggesting that they retained some CsDGAT1 function, and their seeds showed decreased eicosaenoic acid (C20:1) contents and increased C18:3 contents compared to the wild type (WT). The EDD2 lines had a complete knockout of all CsDGAT2 homoeologs and a slightly decreased C18:3 content compared to the WT. In conclusion, CsDGAT1 and CsDGAT2 have a small influence on the seed oil content and have an acyl preference for C20:1 and C18:3, respectively. This finding can be applied to develop oilseed plants containing high omega-3 fatty acids or high oleic acid.

Assessing the genetic associations between plasma lipidomic profiles and psoriasis vulgaris.

Several studies have indicated a potential causal relationship between plasma standard lipids, such as high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), triglycerides (TG), and total cholesterol (TC), and psoriasis. However, few studies have offered causal evidence of lipid species beyond these standard lipids. We conducted an analysis using a genome-wide association study (GWAS) dataset comprising 179 lipid species, including 13 types across four major categories, to identify instrumental variables (IVs) associated with plasma lipids. We utilized two GWAS datasets from the IEU and Finngen for psoriasis vulgaris as the outcome. A two-sample Mendelian randomization (MR) analysis was used to explore the causal relationship between 179 lipid species and psoriasis vulgaris in two datasets. Lipid species showing causal association in both psoriasis datasets were compared for overlap. Our study identified potential causal relationships between six lipid species and psoriasis vulgaris: phosphatidylcholine (16:1_18:2), phosphatidylcholine (18:0_18:2), phosphatidylcholine (18:1_20:4), phosphatidylethanolamine (16:0_18:2), phosphatidylinositol (18:0_20:3), and triacylglycerol (50:1). In summary, elevated plasma levels of phosphatidylcholine (16:1_18:2), phosphatidylcholine (18:0_18:2), phosphatidylethanolamine (16:0_18:2), phosphatidylinositol (18:0_20:3), and triacylglycerol (50:1) may increase the risk of psoriasis vulgaris. Conversely, plasma phosphatidylcholine (18:1_20:4) may play a protective role against psoriasis vulgaris.

A contribution to lipid digestion of Odobenidae family: Computational analysis of gastric and pancreatic lipases from walrus (Odobenus rosmarus divergens).

Triacylglycerols (TAGs) are a primary energy source for marine mammals during lipid digestion. Walruses (Odobenus rosmarus divergens) consume prey with a high content of long-chain polyunsaturated fatty acids; however, their digestive physiology and lipid digestion remain poorly studied. The present study aims to model and characterize the gastric (PWGL) and pancreatic (PWPL) lipases of Pacific walruses using an in-silico approach. The confident 3D models of PWGL and PWPL were obtained via homology modeling and protein threading and displayed the structural features of lipases. Molecular docking analysis demonstrated substrate selectivity for long-chain TAG (Trieicosapentaenoin; TC20:5n-3) in PWGL and short-chain TAG (Trioctanoin; TC8:0) in PWPL. Molecular dynamics simulations demonstrate that PWGL bound to tridocosahexaenoin (TC22:6n-3), the protein is considerably stable at all three salinity conditions, but fluctuations are observed in the regions associated with catalytic sites and the lid, indicating the potential hydrolysis of the substrate. This is the first study to report on the digestion of TAGs in walruses, including modeling and lipases characterization and proposing a digestive tract for pinnipeds.

Exploring Iberian ham triacylglycerols: Unraveling the influence of growing area, season, breed, and feeding patterns through innovative compositional data analysis.

This research examined the triacylglycerol composition of Iberian pig hams from Sevilla province, focusing on the influence of growing area, season, breed, age, montanera duration, and feeding types. Compositional data analysis (CoDA) tools and standard multivariate statistics were employed to analyse the original and CoDa-transformed data. ANOVA (ilr) and ANCOVA (log ratios) revealed significant effects of season, feeding type, and towns on triacylglycerol profiles, while montanera showed limited or no effect. Breeds and age were deemed irrelevant. Various discriminant analysis (DA) methods consistently distinguished samples from the 2004/2005 season and the cebo feeding type but struggled with other distinctions. PLS-R analysis indicated that bellota feeding was associated with triacylglycerols rich in oleic acid, while cebo was predominantly linked to those containing palmitic and stearic acids. The study challenges traditional assumptions about the effects of montanera, breeds, and age on Iberian pig hams and highlights the need for further investigation.

Identification of key genes for triacylglycerol biosynthesis and storage in herbaceous peony (Paeonia lactifolra Pall.) seeds based on full-length transcriptome.

BACKGROUND: The herbaceous peony (Paeonia lactiflora Pall.) is extensively cultivated in China due to its root being used as a traditional Chinese medicine known as 'Radix Paeoniae Alba'. In recent years, it has been discovered that its seeds incorporate abundant unsaturated fatty acids, thereby presenting a potential new oilseed plant. Surprisingly, little is known about the full-length transcriptome sequencing of Paeonia lactiflora, limiting research into its gene function and molecular mechanisms. RESULTS: A total of 484,931 Reads of Inserts (ROI) sequences and 1,455,771 full-Length non-chimeric reads (FLNC) sequences were obtained for CDS prediction, TF analysis, SSR analysis and lncRNA identification. In addition, gene function annotation and gene structure analysis were performed. A total of 4905 transcripts were related to lipid metabolism biosynthesis pathway, belonging to 28 enzymes. We use these data to identify 10 oleosin (OLE) and 5 diacylglycerol acyltransferase (DGAT) gene members after de-redundancy. The analysis of physicochemical properties and secondary structure showed them similarity in gene family respectively. The phylogenetic analysis showed that the distribution of OLE and DGAT family members was roughly the same as that of Arabidopsis. Quantitative real-time polymerase chain reaction (qRT-PCR) analyses revealed expression changes in different seed development stages, and showed a trend of increasing and then decreasing. CONCLUSION: In summary, these results provide new insights into the molecular mechanism of triacylglycerol (TAG) biosynthesis and storage during the seedling stage in Paeonia lactiflora. It provides theoretical references for selecting and breeding oil varieties and understanding the functions of oil storage as well as lipid synthesis related genes in Paeonia lactiflora.

Increased triacylglycerol production in Rhodococcus opacus by overexpressing transcriptional regulators.

Lignocellulosic biomass is currently underutilized, but it offers promise as a resource for the generation of commercial end-products, such as biofuels, detergents, and other oleochemicals. Rhodococcus opacus PD630 is an oleaginous, Gram-positive bacterium with an exceptional ability to utilize recalcitrant aromatic lignin breakdown products to produce lipid molecules such as triacylglycerols (TAGs), which are an important biofuel precursor. Lipid carbon storage molecules accumulate only under growth-limiting low nitrogen conditions, representing a significant challenge toward using bacterial biorefineries for fuel precursor production. In this work, we screened overexpression of 27 native transcriptional regulators for their abilities to improve lipid accumulation under nitrogen-rich conditions, resulting in three strains that accumulate increased lipids, unconstrained by nitrogen availability when grown in phenol or glucose. Transcriptomic analyses revealed that the best strain (#13) enhanced FA production via activation of the ß-ketoadipate pathway. Gene deletion experiments confirm that lipid accumulation in nitrogen-replete conditions requires reprogramming of phenylalanine metabolism. By generating mutants decoupling carbon storage from low nitrogen environments, we move closer toward optimizing R. opacus for efficient bioproduction on lignocellulosic biomass.

Phospholipid Acyltransferases: Characterization and Involvement of the Enzymes in Metabolic and Cancer Diseases.

This review delves into the enzymatic processes governing the initial stages of glycerophospholipid (phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine) and triacylglycerol synthesis. The key enzymes under scrutiny include GPAT and AGPAT. Additionally, as most AGPATs exhibit LPLAT activity, enzymes participating in the Lands cycle with similar functions are also covered. The review begins by discussing the properties of these enzymes, emphasizing their specificity in enzymatic reactions, notably the incorporation of polyunsaturated fatty acids (PUFAs) such as arachidonic acid and docosahexaenoic acid (DHA) into phospholipids. The paper sheds light on the intricate involvement of these enzymes in various diseases, including obesity, insulin resistance, and cancer. To underscore the relevance of these enzymes in cancer processes, a bioinformatics analysis was conducted. The expression levels of the described enzymes were correlated with the overall survival of patients across 33 different types of cancer using the GEPIA portal. This review further explores the potential therapeutic implications of inhibiting these enzymes in the treatment of metabolic diseases and cancer. By elucidating the intricate enzymatic pathways involved in lipid synthesis and their impact on various pathological conditions, this paper contributes to a comprehensive understanding of these processes and their potential as therapeutic targets.