Einhardtii in which C18:36,9,12 and C18:46,9,12,15 are replaced by C18:35,9,12 and C18:45,9,12,15, respectively [141]. The relative abundance of fatty acids in C. zofingiensis varies tremendously based on culture conditions, for instance, the main monounsaturated fatty acid C18:19 includes a significantly larger percentage below ND + HL than under favorable growth conditions, using a reduced percentage of polyunsaturated fatty acids [13]. As well as the polar glycerolipids present in C. reinhardtii, e.g., monogalactosyl diacylglycerol (MGDG), digalactosyl diacylglycerol (DGDG), sulfoquinovosyl diacylglycerol (SQDG), phosphatidylglycerol (PG), phosphatidylinositol (PI), phosphatidylethanolamine (PE) and diacylglycerol-N,N,N-trimethylhomoserine (DGTS), C. zofingiensis contains phosphatidylcholine (Computer) too [18, 37, 38]. As indicated in Fig. four based on the MAO-B manufacturer information from Liu et al. [37], beneath nitrogen-replete favorable development conditions, the lipid fraction accounts for only a compact proportion of cell mass, of which membrane lipids particularly the glycolipids MGDG and DGDG are the big lipid classes. By contrast, below such pressure situation as ND, the lipid fraction dominates the proportion of cell mass, contributed by the enormous increase of TAG. Polar lipids, however, lower severely in their proportion.Fig. four Profiles of fatty acids and glycerolipids in C. zofingiensis under ACAT2 Biological Activity nitrogen replete (NR) and nitrogen deprivation (ND) situations. DGDG, digalactosyl diacylglycerol; DGTS, diacylglycerol-N,N,N-tri methylhomoserine; MGDG, monogalactosyl diacylglycerol; SQDG, sulfoquinovosyl diacylglycerol; PE, phosphatidylethanolamine; PG, phosphatidylglycerol; PI, phosphatidylinositol; TAG, triacylglycerol; TFA, total fatty acidsFatty acid biosynthesis, desaturation and degradationGreen algae, comparable to vascular plants, execute de novo fatty acid synthesis in the chloroplast, using acetyl-CoA as the precursor and developing block [141]. A number of routes are proposed for making acetyl-CoA: from pyruvate mediated by pyruvate dehydrogenase complex (PDHC), from pyruvate via PDHC bypass, from citrate via the ATP-citrate lyase (ACL) reaction, and from acetylcarnitine through carnitine acetyltransferase reaction [144]. C. zofingiensis genome harbors genes encoding enzymes involved within the first three routes [37]. Taking into account the predicted subcellular localization information and facts and transcriptomics data [18, 37, 38], C. zofingiensis most likely employs each PDHC and PDHC bypass routes, but mainly the former one particular, to supply acetyl-CoA in the chloroplast for fatty acid synthesis. De novo fatty acid synthesis in the chloroplast consists of a series of enzymatic steps mediated by acetyl-CoAZhang et al. Biotechnol Biofuels(2021) 14:Web page ten ofcarboxylase (ACCase), malonyl-CoA:acyl carrier protein (ACP) transacylase (MCT), and form II fatty acid synthase (FAS), an very easily dissociable multisubunit complicated (Fig. five). The formation of malonyl-CoA from acetyl-CoA, a committed step in fatty acid synthesis, is catalyzed by ACCase [145]. The chloroplast-localized ACCase in C. zofingiensis is a tetrasubunit enzyme consisting of -carboxyltransferase, -carboxyltransferase, biotin carboxyl carrier protein, and biotin carboxylase.These subunits are well correlated at the transcriptional level [18, 33, 37, 39]. Malonyl-CoA must be converted to malonyl-acyl carrier protein (ACP), via the action of MCT, just before getting into the subsequent condensation reactions for acyl chai.
