Abstract. Biotransformations are chemical reactions carried out by microorganisms on organic substrates. can be regio-, chemo-, stereo- and enantio-selective. Bioreductions of great interest to the food pharmaceutical industries as they help reduce costs impacts environment. In this work, following biotransformations chalcones were performed: (2E)-1-(4-hydroxy-phenyl)-3-(2-methoxy-phenyl)-prop-...

Silver nanoparticles (AgNPs) are extensively used in various industries due to their unique physico-chemical and antimicrobial properties. Many natural biomolecules in plants (inactivated plant tissue, plant extracts and living plant) such as proteins/enzymes, amino acids, polysaccharides, alkaloids, alcoholic compounds, and vitamins could be involved in bioreduction, formation and stabilizatio...

101 CHARACTERIZATION OF CHROMIUM(VI) BIOREDUCTION AND CHROMIUM(III) BINDING TO ALFALFA BIOMASS K. Dokken, G. Gamez, I. Herrera, K.J. Tiemann, N.E. Pingitore, R.R. Chianelli, and J.L. Gardea-Torresdey Department of Chemistry and Environmental Science and Engineering,University of Texas at El Paso, El Paso, TX 79968; Phone: (915) 747-5359; Fax: (915) 747-5847. Department of Geological Sciences, U...

To develop a nicotinamide-independent single flavoenzyme system for the asymmetric bioreduction of C=C bonds, four types of hydrogen donor, encompassing more than 50 candidates, were investigated. Six highly potent, cheap, and commercially available co-substrates were identified that (under the optimized conditions) resulted in conversions and enantioselectivities comparable with, or even super...

Asymmetric bioreduction of an (E)-β-cyano-2,4-dienoic acid derivative by ene-reductases allowed a shortened access to a precursor of pregabalin [(S)-3-(aminomethyl)-5-methylhexanoic acid] possessing the desired configuration in up to 94% conversion and >99% ee. Deuterium labelling studies showed that the nitrile moiety was the preferred activating/anchor group in the active site of the enzyme o...

Directly adjacent to the Chesapeake Bay lies the Aberdeen Proving Ground, a U.S. Army facility where testing of armor-piercing ammunitions has resulted in the deposition of >70,000 kg of depleted uranium (DU) to local soils and sediments. Results of previous environmental monitoring suggested limited mobilization in the impact area and no transport of DU into the nation's largest estuary. To de...

The fate of pertechnetate ((99)Tc(VII)O(4)(-)) during bioreduction was investigated in the presence of 2-line ferrihydrite (Fh) and various dissimilatory metal reducing bacteria (DMRB) (Geobacter, Anaeromyxobacter, Shewanella) in comparison with TcO(4)(-) bioreduction in the absence of Fh. In the presence of Fh, Tc was present primarily as a fine-grained Tc(IV)/Fe precipitate that was distinct ...

The synthesis of pharmaceuticals and catalysts more and more relies on enantiopure chiral building blocks. These can be produced in an environmentally benign and efficient way via bioreduction of prochiral ketones catalyzed by dehydrogenases. A productive source of these biocatalysts is the yeast Saccharomyces cerevisiae, whose genome also encodes a reductase catalyzing the sequential reduction...

We aim to understand the scale-dependent evolution of uranium bioreduction during a field experiment at a former uranium mill site near Rifle, Colorado. Acetate was injected to stimulate Fe-reducing bacteria (FeRB) and to immobilize aqueous U(VI) to insoluble U(IV). Bicarbonate was coinjected in half of the domain to mobilize sorbed U(VI). We used reactive transport modeling to integrate hydrau...