Transcriptional engineering has received significant attention for improving strains by modulating the behavior of transcription factors, which could be used to reprogram a series of gene transcriptions and enable multiple simultaneous modifications at the genomic level. In this study, engineering of the cAMP receptor protein (CRP) was explored with the aim of subtly balancing entire pathway networks and potentially improving lycopene production without significant genetic intervention in other pathways. Amino acid mutations were introduced to CRP by error-prone PCR, and three variants (mcrp26, mcrp159 and mcrp424) with increased lycopene productivity were screened. Combinations of three point mutations were then created via site-directed mutagenesis. The best mutant gene (mcrp26) was integrated into the genome of E. coli BW25113-BIE to replace the wild-type crp gene (MT-1), which resulted in a higher lycopene production (18.49mg/g DCW) compared to the original strain (WT). The mutant strain MT-1 was further investigated in a 10-L bench-top fermentor with a lycopene yield of 128mg/l at 20h, approximately 25% higher than WT. DNA microarray analyses showed that 396 genes (229 up-regulated and 167 down-regulated) were differentially expressed in the mutant MT-1 compared to WT. Finally, the introduction of the mutant crp gene (mcrp26) increased β-carotene production in E. coli. This is the first report of improving the phenotype for metabolite overproduction in E. coli using a CRP engineering strategy.
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http://dx.doi.org/10.1016/j.jbiotec.2015.02.006 | DOI Listing |
Mar Drugs
January 2025
College of Food Science and Engineering, Ningbo University, Ningbo 315211, China.
is an important source of natural β-carotene (containing and isomers) for industrial production. The phytohormone salicylic acid (SA) has been proven to have impacts on the stress resistance of higher plants, but research on microalgae is currently unclear. In this study, the effects of SA on the growth, biochemical composition, antioxidant enzyme activity, key enzymes of β-carotene synthesis, and cis-and trans-isomers of β-carotene in under different salt concentrations were investigated.
View Article and Find Full Text PDFMicrob Cell Fact
January 2025
National Center of Technology Innovation for Synthetic Biology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
Background: Ogataea polymorpha, a non-conventional methylotrophic yeast, has demonstrated significant potential for heterologous protein expression and the production of high-value chemicals and biopharmaceuticals. However, the lack of precise and efficient genome editing tools severely hinders the construction of cell factories. Although the CARISP-Cas9 system has been established in Ogataea polymorpha, the gene editing efficiency, especially for multiple genes edition, needs to be further improved.
View Article and Find Full Text PDFPlant Physiol Biochem
January 2025
Department of Biology, Garmsar Branch, Islamic Azad University, Garmsar, Iran.
This study explored morphological, physiological, molecular, and epigenetic responses of tomatoes (Solanum lycopersicum) to soil contamination with polyethylene nanoplastics (PENP; 0.01, 0.1, and 1 gkg soil).
View Article and Find Full Text PDFBMC Vet Res
January 2025
Department of Animal Production, Faculty of Agriculture, Zagazig University, Zagazig, 44511, Egypt.
Animal husbandry development is influenced by various factors, with heat stress (HS) being a significant factor. The aim of this experiment was to explore the potential of natural antioxidants such as vitamin C (VITC), vitamin E (VITE), lycopene (LYC), and allicin (AL) in enhancing growth, immune function and maintaining the redox status of fattening rabbits under HS. Male weaning rabbits (n = 150, 5 weeks of age) were randomly assigned to 5 groups.
View Article and Find Full Text PDFNat Commun
January 2025
Washington University in St. Louis, Saint Louis, MO, USA.
In-space biomanufacturing provides a sustainable solution to facilitate long-term, self-sufficient human habitation in extraterrestrial environments. However, its dependence on Earth-supplied feedstocks renders in-space biomanufacturing economically nonviable. Here, we develop a process termed alternative feedstock-driven in-situ biomanufacturing (AF-ISM) to alleviate dependence on Earth-based resupply of feedstocks.
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