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Mathematical Modeling for Advanced PHA Biosynthesis
Published in Martin Koller, The Handbook of Polyhydroxyalkanoates, 2020
Predrag Horvat, Martin Koller, Gerhart Braunegg
Respecting the high number of microbial species that produce PHA of various compositions, different polyester synthases were isolated and characterized. Their biocatalytic function is that of an acyltransferase, hence, it transfers acyl-groups. In the special case of PHB homopolyester biosynthesis, the following reaction can be defined: (R)-3-hydroxybutanoyl-CoA+[(R)-3- hydroxybutanoate](n)→[(R)-3- hydroxybutanoate](n+1)+CoA
Derivatization Reactions in Trace Chemical Analysis
Published in Pradyot Patnaik, Handbook of Environmental Analysis, 2017
Derivatization of amines, effectively are carried out by acylation reactions, though other methods involving nonacylation routes are well known. Such acylating reagents for amines include acyl chlorides, acid anhydrides, acyl amides, and acyl imidazoles. These reagents react with amino groups under mild conditions. The general reactions involving primary and secondary amines with acid anhydrides, acid chlorides, and acid amides are shown below, respectively. The reactions with imidazoles are discussed above for amines, alcohols, phenols, and amides. Anhydride: RR′NH + R″C(=O)–O–C(=O)R″ → RR′NC(=O)R″ + R″COOHAcid chloride: RR′NH + R″C(=O)Cl → RR′NC(=O)R″ + HClAcid amide: RR′NH + [R″(C=O)]2NCH3 → RR′NC(=O)R″ + R″C(=O)NHCH3
Microalgae Biomass as an Alternative to Fossil Carbons
Published in Jorge M.T.B. Varejão, Biomass, Bioproducts and Biofuels, 2022
Joana D Ferreira, Clara B Martins, Mariana FG Assunção, Lilia MA Santos
Lipids are classified as polar or nonpolar according to their chemical structure and polarity. In microalgae, polar lipids, which include phospholipids and glycolipids, are present in cell membranes. Nonpolar or neutral lipids, used as an energy source, comprise acylglycerols (mono, di and tri) and free fatty acids (Sati et al. 2019). Triacylglycerols (TAGs) are the main target material for the production of biodiesel, especially if it has a lesser degree of unsaturation. Thus, microalgae with large amounts of lipids and relatively low amounts of TAGs are not considered suitable for the production of biodiesel (Sati et al. 2019). Some species of microalgae with lipids with a high TAG content, namely Chlorella sp., Scenedesmus sp. and Nannochloropsis sp., were studied for the production of biodiesel and subsequent applications of biofuels (Dong et al. 2016). The lipid biosynthesis in microalgae occurs in the chloroplast through the fatty acid pathway. (Gouveia et al. 2017). This is one of the main pathways of cellular metabolism, synthesizing fatty acids from acyl groups, necessary for the construction of the cell membrane and storage lipids. Apparently the process is similar to plant cells, the production of fatty acids requires acyl groups in the form of Acetyl-CoA, energy (ATP) and reducing agents such as NADPH, in a multi-enzymatic sequential process (Figure 2) (Khozin and Goldberg 2016). Many studies are focused on identifying the lipid synthesis pathways in microalgae, namely on the identification and characterization of the main genes and key enzymes involved in the process (Yu et al. 2011, Gouveia et al. 2017).
Microbial and functional characterization of granulated sludge from full-scale UASB thermophilic reactor applied to sugarcane vinasse treatment
Published in Environmental Technology, 2022
Franciele Pereira Camargo, Isabel Kimiko Sakamoto, Tiago Palladino Delforno, Cédric Midoux, Iolanda Cristina Silveira Duarte, Edson Luiz Silva, Ariane Bize, Maria Bernadete Amâncio Varesche
The K01897 (0.081%), a long-chain acyl-CoA synthetase, could be related to several genera, such as Crocinitomix (14.1%), Hylemonella (12.0%), Sulfurimonas (10.5%), Marinobacter (6.1%), Marinospirillum (2.4%) and Pseudomonas (1.6%). It acts in the fatty acids biosynthesis from Acetyl-CoA in a wide range of long-chain saturated and unsaturated fatty acids, binding them to a CoA molecule, generating a diphosphate and a long-chain fatty acyl-CoA, requiring an ATP molecule in the process. In the same way, it can also acts in the Hexadecanoate degradation in the Fatty acids degradation pathway. The K06445 (0.0057%), acts in the same pathways mentioned, as an acyl-CoA dehydrogenase.