Engineered heterologous multi-gene metabolic pathways often suffer from flux imbalance and toxic metabolites, as the production host typically lacks the regulatory mechanisms for the heterologous pathway. Here, we first coordinated the expression of all genes of the mevalonate (MEV) pathway from Saccharomyces cerevisiae using the tunable intergenic regions (TIGRs), and then dynamically regulated the TIGR-mediated MEV pathway to prevent the accumulation of toxic metabolites by using IPP/FPP-responsive promoter. After introduction of the dynamically controlled TIGR-mediated MEV pathway into Escherichia coli, the content and concentration of zeaxanthin in shaker flask cultures were 2.0- and 2.1-fold higher, respectively, than those of the strain harboring the statically controlled non-TIGR-mediated MEV pathway. The content and concentration of zeaxanthin in E. coli ZEAX (pZSP-MevT-MevBIS-2) reached 722.46mg/L and 23.16mg/g dry cell weight (DCW), respectively, in 5.0L fed-batch fermentation. We also comparatively analyzed the proteomes between E. coli ZEAX and E. coli ZEAX (pZSP-MevT-MevBIS-2) to understand the mechanism of zeaxanthin biosynthesis. The results of the comparative proteomes demonstrate that zeaxanthin overproduction may be associated with increased precursor availability, increased NADPH availability, increased ATP availability, oxidative stress response, and increased membrane storage capacity for zeaxanthin due to changes in both cellular shape and membrane composition.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.ymben.2016.07.012 | DOI Listing |
J Virol
January 2025
Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
Measles virus (MeV) is a highly contagious respiratory virus transmitted via aerosols. To understand how MeV exits the airways of an infected host, we use unpassaged primary cultures of human airway epithelial cells (HAE). MeV typically remains cell-associated in HAE and forms foci of infection, termed infectious centers, by directly spreading cell-to-cell.
View Article and Find Full Text PDFEcotoxicol Environ Saf
January 2025
Plant Production Department, Faculty of Agriculture Saba Basha, Alexandria University, Alexandria 21531, Egypt; Work Station of Science and Technique for Post-doctoral in Sugar Beet Institute Afliated to Heilongjiang University, 74 Xuefu Road, Harbin 150000, Heilongjiang, China.
Ion beam mutagenesis is an advanced technique capable of inducing substantial changes in plants, resulting in noticeable alterations in their growth. However, the precise molecular mechanisms underlying the effects of radiation on soybeans remain unclear. This study investigates the impact of ionizing radiation on soybean development through a comprehensive approach that integrates transcriptomics and metabolomics.
View Article and Find Full Text PDFPlants (Basel)
December 2024
Department of Agricultural Sciences, University of Naples Federico II, 80055 Naples, Italy.
Numerous challenges are posed by the extra-terrestrial environment for space farming and various technological growth systems are being developed to allow for microgreens' cultivation in space. Microgreens, with their unique nutrient profiles, may well integrate the diet of crew members, being a natural substitute for chemical food supplements. However, the space radiation environment may alter plant properties, and there is still a knowledge gap concerning the effects of various types of radiation on plants and specifically on the application of efficient and rapid methods for selecting new species for space farming, based on their radio-resistance.
View Article and Find Full Text PDFPhys Chem Chem Phys
December 2024
Center of New Technologies, University of Warsaw, 02089 Warsaw, Poland.
Based on density functional theory calculations, we propose a new pathway toward compounds featuring flat [AgF] layers which mimic [CuO] layers in high-temperature oxocuprate superconductor precursors. Calculations predict the dynamic (phonon) and energetic stability of the new phases over diverse substrates. For some compounds with ferro orbital ordering, we find a gigantic intrasheet superexchange constant of up to -211 meV (DFT+) and -256 meV (SCAN), calculated for hypothetical (CsMgF)KAgF intergrowth.
View Article and Find Full Text PDFPhys Rev Lett
November 2024
Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!