The aim of this work was the establishment of a novel method to determine the metabolic load on host-cell metabolism resulting from recombinant protein production in Escherichia coli. This tool can be used to develop strategies to optimise recombinant fermentation processes through adjustment of recombinant-protein expression to the biosynthetic capacity of the host-cell. The signal molecule of the stringent-response network, guanosine tetraphosphate (ppGpp), and its precursor nucleotides were selected for the estimation of the metabolic load relating to recombinant-protein production. An improved analytical method for the quantification of nucleotides by ion-pair, high-performance liquid chromatography was established. The host-cell response upon overexpression of recombinant protein in fed-batch fermentations was investigated using the production of human superoxide dismutase (rhSOD) as a model system. E. coli strains with different recombinant systems (the T7 and pKK promoter system) exerting different loads on host-cell metabolism were analysed with regard to intracellular nucleotide concentration, rate of product formation and plasmid copy number.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s002530051612 | DOI Listing |
Appl Microbiol Biotechnol
January 2025
College of Marine and Bioengineering, Yancheng Institute of Technology, Yancheng, 224051, PR China.
L-valine holds wide-ranging applications in medicine, food, feed, and various industrial sectors. Escherichia coli, a pivotal strain in industrial L-valine production, features a concise fermentation period and a well-defined genetic background. This study focuses on mismatch repair genes (mutH, mutL, mutS, and recG) and genes associated with mutagenesis (dinB, rpoS, rpoD, and recA), employing a high-glucose adaptive culture in conjunction with metabolic modifications to systematically screen for superior phenotypes.
View Article and Find Full Text PDFFood Chem (Oxf)
June 2025
Sciensano, Transversal activities in Applied Genomics (TAG), J. Wytsmanstraat 14, 1050 Brussels, Belgium.
Genetically modified microorganisms (GMM) are frequently employed for the production of microbial fermentation products such as food enzymes. Although presence of the GMM or its recombinant DNA in the final product is not authorized, contaminations occur frequently. Insight into the contamination source of a GMM is of crucial importance to allow the competent authorities to take appropriate action.
View Article and Find Full Text PDFSynth Syst Biotechnol
June 2025
School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023, China.
Abscisic acid (ABA) is an important plant growth regulator with broad applications in agriculture, forestry, and other fields. Currently, the industrial production of ABA primarily relies on microbial fermentation using , but its genetic toolbox is limited. To address this, we first screened 10 strong constitutive promoters from the genome of through transcriptomic analysis.
View Article and Find Full Text PDFJ Biotechnol
January 2025
Interdisciplinary Program of Bioenergy and Biomaterials Graduate School, Chonnam National University, Gwangju, 61186, Republic of Korea; Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju, 61186, Republic of Korea. Electronic address:
This study was aimed to develop a highly productive microbial fermentation process for gamma-aminobutyric acid (GABA) production from glucose. For this, an efficient GABA-producing E. coli strain was firstly developed through metabolic engineering with a strategy of increasing the flux of GABA biosynthetic pathway and deleting or repressing the GABA shunt pathways that compete with GABA biosynthesis.
View Article and Find Full Text PDFFood Chem
January 2025
Department of Biochemistry, Phramongkutklao College of Medicine, Phramongkutklao Hospital, Bangkok 10400, Thailand. Electronic address:
In this study, maltotriosyl-erythritol (EG) was synthesized as a novel prebiotic candidate via transglycosylation using recombinant amylomaltase (AMase) from Thermus sp. Tapioca starch served as the glucosyl donor, and erythritol as the acceptor. High-performance liquid chromatography (HPLC) revealed an EG yield of 14.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!