This work simulates the production of methyl crotonate from various industrial wastewaters. In the upstream process, wastewater is fermented into volatile fatty acids which are then converted into polyhydroxyalkanoates (PHA) by means of mixed microbial cultures. In the downstream, PHA undergoes a series of thermolysis and esterification reactions to produce methyl crotonate. The origin of the wastewater was found to have a great influence on the composition of the PHA with the effluent of a candy bar factory producing a high polyhydroxybutyrate/polyhydroxyvalerate ratio of 86/14 in favour of methyl crotonate production. It was observed that the use of intracellular polyhydroxybutyrate, instead of purified, significantly lowers the number of separation steps and yet reduces the methyl crotonate recovery by only 20 %. An operating pressure higher than 18 bar led to more transesterification of polyhydroxybutyrate, producing byproducts instead of methyl crotonate. Finally, a 3 h reaction was found sufficient for completion of polyhydroxybutyrate conversion.
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http://dx.doi.org/10.1016/j.biortech.2022.127994 | DOI Listing |
Microbiol Spectr
November 2024
Department of Biological and Chemical Engineering, Aarhus University, Aarhus C, Denmark.
Short-chain carboxylic acids (SCCAs) that are naturally produced by microbial fermentation play an essential role in delaying microbial spoilage. SCCAs are structurally diverse, but only a few of them are routinely used in food biopreservation. This study investigated the effects of environmental pH and intrinsic properties of 21 structurally different SCCAs on the antimicrobial and antibiofilm activity against .
View Article and Find Full Text PDFSci Rep
May 2024
State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (R2BGL), Inner Mongolia University, 24 Zhaojun Rd., Hohhot, 010070, China.
Lysine crotonylation (Kcr) is a recently discovered histone acylation modification that is closely associated with gene expression, cell proliferation, and the maintenance of stem cell pluripotency and indicates the transcriptional activity of genes and the regulation of various biological processes. During cell culture, the introduction of exogenous croconic acid disodium salt (Nacr) has been shown to modulate intracellular Kcr levels. Although research on Kcr has increased, its role in cell growth and proliferation and its potential regulatory mechanisms remain unclear compared to those of histone methylation and acetylation.
View Article and Find Full Text PDFMacromol Rapid Commun
July 2024
Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación en Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, Campus Universitario, Alcalá de Henares, Madrid, 28871, Spain.
Within bioplastics, natural poly(3-hydroxybutyrate) (PHB) stands out as fully biocompatible and biodegradable, even in marine environments; however, its high isotacticity and crystallinity limits its mechanical properties and hence its applications. PHB can also be synthesized with different tacticities via a catalytic ring-opening polymerization (ROP) of rac-β-butyrolactone (BBL), paving the way to PHB with better thermomechanical and processability properties. In this work, the catalyst family is extended based on aluminum phenoxy-imine methyl catalyst [AlMeL], that reveals efficient in the ROP of BBL, to the halogeno analogous complex [AlClL].
View Article and Find Full Text PDFJ Org Chem
March 2024
The School of Chemistry, The University of Manchester, Manchester M13 9PL, U.K.
3-Oxidopyraziniums are azomethine ylides derived from 2(1)-pyrazinones that can undergo 1,3-dipolar cycloadditions with acrylate and acrylic acid derivatives. The cycloaddition of 1-(4-methoxybenzyl)-5,6-dimethyl-3-oxidopyrazinium with methyl and -butyl acrylate and with methyl crotonate afforded a 3,8-diazabicyclo[3.2.
View Article and Find Full Text PDFBeilstein J Org Chem
January 2024
Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria.
The reactions of 2,4-di--butyl-6-(diphenylphosphino)phenol and various Michael acceptors (acrylonitrile, acrylamide, methyl vinyl ketone, several acrylates, methyl vinyl sulfone) yield the respective phosphonium phenolate zwitterions at room temperature. Nine different zwitterions were synthesized and fully characterized. Zwitterions with the poor Michael acceptors methyl methacrylate and methyl crotonate formed, but could not be isolated in pure form.
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