In Escherichia coli , 1-deoxy- d -xylulose (or its 5-phosphate, DXP) is the biosynthetic precursor to isopentenyl diphosphate [Broers, S. T. J. (1994) Dissertation (Eidgenössische Technische Hochschule, Zürich)], thiamin, and pyridoxol [Himmeldirk, K., Kennedy, I. A., Hill, R. E., Sayer, B. G. & Spenser, D. (1996) Chem. Commun . 1187–1188]. Here we show that an open reading frame at 9 min on chromosomal map of E. encodes enzyme ( eoxy x ylulose-5- p hosphate synthase, DXP synthase)...

Abstract The biotechnological transformation of vegetable oils and animal fats has been successfully developed up to an industrial scale in recent years. However, biotechnology is still a niche technology the oleochemical industry, which classically relies on chemical processes. Nevertheless, impact rising, with increasing number biotech‐based products, especially area lipid‐derived specialties, entering market. In this review we give summary industrially relevant processes field lipid biotechnology.

Transketolase A was purified to apparent homogeneity from recombinant Escherichia coli K12 cells carrying the homologous cloned tktA gene on a pUC19‐derived plasmid. These exhibited transketolase activity in crude extracts of up 9.7 U/mg compared ≤0.1 wild‐type cells. strain by successive ammonium sulfate precipitations and two anion‐exchange chromatography steps (Q‐Sepharose FF, Fractogel EMD‐DEAE column) afforded an apparently homogeneous protein band SDS/PAGE. The enzyme, both its active...

Abstract N-Acyl-amino acids can act as mild biobased surfactants, which are used, e.g., in baby shampoos. However, their chemical synthesis needs acyl chlorides and does not meet sustainability criteria. Thus, the identification of biocatalysts to develop greener routes is desirable. We describe a novel aminoacylase from Paraburkholderia monticola DSM 100849 (PmAcy) was identified, cloned, evaluated for its N-acyl-amino acid potential. Soluble protein obtained by expression lactose...

Abstract Transaldolase catalyzes transfer of a dihydroxyacetone moiety from ketose donor to an aldose acceptor. During catalysis, Schiff‐base intermediate between and the ϵ‐amino group lysine residue at active site enzyme is formed. This has been trapped by reduction with potassium borohydride, crystal structure this complex determined 2.2 Å resolution. The overall structures native are very similar; formation induces no large conformational changes. covalently linked side chain Lys 132...

A previously recognized open reading frame (T. Yura, H. Mori, Nagai, T. Nagata, A. Ishihama, N. Fujita, K. Isono, Mizobuchi, and Nakata, Nucleic Acids Res. 20:3305-3308) from the 0.2-min region of Escherichia coli K-12 chromosome is shown to encode a functional transaldolase activity. After cloning gene onto high-copy-number vectors, B (D-sedoheptulose-7-phosphate:D-glyceraldehyde-3-phosphate dihydroxyacetone transferase; EC 2.2.1.2) was overexpressed up 12.7 U mg protein-1 compared with...

Abstract Starmerella bombicola is known to produce sub‐terminally hydroxylated lactonic sophorolipids (SLs), while Candida kuoi synthesizes acidic open chain SLs with terminally fatty acids. Upon feeding glucose and alcohols both strains form long‐chain nonionic SLs. According structure elucidation the consist of a acid esterified alcohol linked via glycoside bond diacetylated sophorose unit. Palmityl, stearyl, oleyl lead products lipid lengths C32 or C36. Oleyl preferred substrate leading...

Aminoacylases are highly promising enzymes for the green synthesis of acyl-amino acids, potentially replacing environmentally harmful Schotten-Baumann reaction. Long-chain acids can serve as strong surfactants and emulsifiers, with application in cosmetic industries. Heterologous expression these enzymes, however, is often hampered, limiting their use industrial processes.We identified a novel mycobacterial aminoacylase gene from Mycolicibacterium smegmatis MKD 8, cloned expressed it...

Biobased polymers derived from plant oils are sustainable alternatives to petro based polymers. In recent years, multienzyme cascades have been developed for the synthesis of biobased ω-aminocarboxylic acids, which serve as building blocks polyamides. this work, we a novel enzyme cascade 12-aminododeceneoic acid, precursor nylon-12, starting linoleic acid. Seven bacterial ω-transaminases (ω-TAs) were cloned, expressed in Escherichia coli and successfully purified by affinity chromatography....

ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTChemical and Enzymatic Synthesis of 1-Deoxy-d-xylulose-5-phosphateSean V. Taylor, Long D. Vu, Tadhg P. Begley, Ulrich Schörken, Sigrid Grolle, Georg A. Sprenger, Stephanie Bringer-Meyer, Hermann SahmView Author Information Department Chemistry, Cornell University, Baker Laboratory, Ithaca, New York 14853 Institut für Biotechnologie, 1 des Forschungszentrums Jülich GmbH, Postfach 1913, D-52425 Jülich, Germany Cite this: J. Org. Chem. 1998, 63, 7,...

Native lipase B from Candida antarctica was evaluated for ester production in the presence of hydrophilic green solvents including DES. Ester yields up to 98% were achieved without removing water system single step transformations. Analysis lipid phase exhibited a low content 0.29 mg/mL DES contrast 2.5 solvent. Thus, adsorbing properties are responsible equilibrium shift towards synthesis, which even observed more than 20% total. Non‐immobilized CalB surprisingly active with logP‐values...

Abstract Current changes in environmental legislation and customer demands set an urge for the development of more sustainable surfactants. Thus, objective this work was novel environmentally friendly amino acid Combining Diels–Alder cyclization myrcene with maleic or citraconic anhydride followed by ring opening acids enabled a synthesis route principal 100% atom economy. Variation resulted large structural variety anionic amphoteric Lysine gave access to either mono-acylated product...

The roles of invariant residues at the active site transaldolase B from Escherichia coli have been probed by site‐directed mutagenesis. mutant enzymes D17A, N35A, E96A, T156A, and S176A were purified a talB ‐deficient host analyzed with respect to their 3D structure kinetic behavior. X‐ray analysis showed that side chain replacement did not induce unanticipated structural changes in enzymes. Three mutations, T156A resulted mainly an effect on apparent k cat , little K m values for...

Linoleic acid hydroperoxides are versatile intermediates for the production of green note aroma compounds and bifunctional ω-oxo-acids. An enzyme cascade consisting lipoxygenase, lipase catalase was developed one-pot synthesis 13-hydroperoxyoctadecadienoic starting from safflower oil. Reaction conditions were optimized hydroperoxidation using lipoxygenase 1 Glycine max (LOX-1) in a solvent-free system. The addition surfactant Triton CG-110 improved reaction more than two-fold yields >50%...

Hydroperoxide lyases (HPLs) catalyze the splitting of 13S-hydroperoxyoctadecadienoic acid (13S-HPODE) into green note flavor hexanal and 12-oxo-9(Z)-dodecenoic acid, which is not yet used industrially. Here, HPL from Carica papaya (HPLCP) was cloned functionally expressed in Escherichia coli to investigate synthesis detail. To improve low catalytic activity full-length HPLCP, hydrophobic, non-conserved N-terminal sequence deleted. This enhanced enzyme initial 10 40 U/l. With optimization...

Disruption of the hydrogen bonding network at interface Escherichia coli transaldolase by substitution R300 to a glutamic acid residue resulted in monomeric enzyme basic pH values, with almost no change kinetic parameters. The stability R300A and R300E mutants towards urea thermal inactivation is similar that wild‐type enzyme. X‐ray analysis showed structural changes occurred as consequence side chain replacement. This indicates quaternary structure not required for catalytic activity nor...

The classical chemical synthesis of CLA triglycerides starting from the free fatty acids and glycerol leads to formation additional isomers not suited for applications in field human nutrition. Greener methods a more selective production under gentle reaction conditions were evaluated 1-4. enzymatic works well vacuum with clear preference as substrates comparison alkyl esters. velocity was enhanced significantly by addition basic additives into mixture. A combined one pot designed ethyl...

Abstract In einem Eintopf‐Verfahren werden aus Olefinen durch Hydroformylierung mit Synthesegas (CO/H 2 = 1/1) und nachfolgende säurekatalysierte Umsetzung Glycerin langkettige Acetale in Ausbeuten > 95 % hergestellt. Die erhaltenen Gemische von 5‐ 6‐Ringverbindungen stellen neuartige potenzielle Kraftstoffadditive dar. Durch Optimierung der Reaktionsbedingungen geeignete Katalysatorwahl ([Rh(COD)]acac/Xantphos) gelingt eine hochregioselektive zu den linearen Acetalen. Zur Herstellung...