Search results for "Comamonas"
showing 3 items of 3 documents
The sustainable synthesis of levetiracetam by an enzymatic dynamic kinetic resolution and an ex-cell anodic oxidation
2021
Levetiracetam is an active pharmaceutical ingredient widely used to treat epilepsy. We describe a new synthesis of levetiracetam by a dynamic kinetic resolution and a ruthenium-catalysed ex-cell anodic oxidation. For the enzymatic resolution, we tailored a high throughput screening method to identify Comamonas testosteroni nitrile hydratase variants with high (S)-selectivity and activity. Racemic nitrile was applied in a fed-batch reaction and was hydrated to (S)-(pyrrolidine-1-yl)butaneamide. For the subsequent oxidation to levetiracetam, we developed a ligand-free ruthenium-catalysed method at a low catalyst loading. The oxidant was electrochemically generated in 86% yield. This route pro…
Bacteria from acidic to strongly alkaline insect midguts: Potential sources of extreme cellulolytic enzymes
2012
Abstract Bacterial isolates from the European Corn Borer (ECB) Ostrinia nubilalis and the coleopteran Colorado Potato Beetle (CPB) Leptinotarsa decemlineata midguts were identified and characterized. Twenty-four colonies, selected on solid media with cellulose as the sole carbon source and pH values ranging from 5 to 12, were identified through 16S sequencing as members of the genera Acinetobacter , Comamonas , Klebsiella , Microbacterium , Micrococcus and Sphingobacterium . A complete enzymatic characterization revealed widespread – albeit moderate – cellulase properties in all but one isolate and high xylanase activity in the four CPB isolates. Different enzymatic patterns in terms of opt…
Effect of the applied organic load rate on biodegradable polymer production by mixed microbial cultures in a Sequencing Batch Reactor
2006
This article studies the operation of a new process for the production of biopolymers (polyhydroxyalkanoates, PHAs) at different applied organic load rates (OLRs). The process is based on the aerobic enrichment of activated sludge to obtain mixed cultures able to store PHAs at high rates and yields. A mixture of acetic, lactic, and propionic acids at different concentrations (in the range 8.5-31.25 gCOD/L) was fed every 2 h in a sequencing batch reactor (SBR). The resulting applied OLR was in the range 8.5-31.25 gCOD/L/day. Even though, as expected, the increase in the OLR caused an increase in biomass concentration (up to about 8.7 g COD/L), it also caused a relevant decrease of maximal po…