Converting renewable feedstocks to aromatic compounds using engineered microbes offers a robust approach for sustainable, environment‐friendly, and cost‐effective production of these value‐added products without the reliance on petroleum. In this study, rationally designed E. coli–E. coli co‐culture systems were established for converting glycerol to 3‐hydroxybenzoic acid (3HB). Specifically, the 3HB pathway was modularized and accommodated by two metabolically engineered E. coli strains. The co‐culture biosynthesis was optimized by using different cultivation temperatures, varying the inoculum ratio between the co‐culture strains, recruitment of a key pathway intermediate transporter, strengthening the critical pathway enzyme expression, and adjusting the timing for inducing pathway gene expression. Compared with the E. coli mono‐culture, the optimized co‐culture showed 5.3‐fold improvement for 3HB biosynthesis. This study demonstrated the applicability of modular co‐culture engineering for addressing the challenges of aromatic compound biosynthesis. 相似文献
Sclerotinia stem rot (SSR), caused by the oxalate-secreting necrotrophic fungal pathogen Sclerotinia sclerotiorum, is one of the devastating diseases that causes significant yield loss in soybean (Glycine max). Until now, effective control of the pathogen is greatly limited by a lack of strong resistance in available commercial soybean cultivars. In this study, transgenic soybean plants overexpressing an oxalic acid (OA)-degrading oxalate oxidase gene OXO from wheat were generated and evaluated for their resistance to S. sclerotiorum. Integration and expression of the transgene were confirmed by Southern and western blot analyses. As compared with non-transformed (NT) control plants, the transgenic lines with increased oxalate oxidase activity displayed significantly reduced lesion sizes, i.e., by 58.71–82.73% reduction of lesion length in a detached stem assay (T3 and T4 generations) and 76.67–82.0% reduction of lesion area in a detached leaf assay (T4 generation). The transgenic plants also showed increased tolerance to the externally applied OA (60 mM) relative to the NT controls. Consecutive resistance evaluation further confirmed an enhanced and stable resistance to S. sclerotiorum in the T3 and T4 transgenic lines. Similarly, decreased OA content and increased hydrogen peroxide (H2O2) levels were also observed in the transgenic leaves after S. sclerotiorum inoculation. Quantitative real-time polymerase chain reaction analysis revealed that the expression level of OXO reached a peak at 1 h and 4 h after inoculation with S. sclerotiorum. In parallel, a significant up-regulation of the hypersensitive response-related genes GmNPR1-1, GmNPR1-2, GmSGT1, and GmRAR occurred, eventually induced by increased release of H2O2 at the infection sites. Interestingly, other defense-related genes such as salicylic acid-dependent genes (GmPR1, GmPR2, GmPR3, GmPR5, GmPR12 and GmPAL), and ethylene/jasmonic acid-dependent genes (GmAOS, GmPPO) also exhibited higher expression levels in the transgenic plants than in the NT controls. Our results demonstrated that overexpression of OXO enhances SSR resistance by degrading OA secreted by S. sclerotiorum and increasing H2O2 levels, and eliciting defense responses mediated by multiple signaling pathways.
The International Journal of Life Cycle Assessment - Low carbon footprint agriculture has received increasing attention in the effect of reducing greenhouse gas emissions and mitigating climate... 相似文献
Journal of Industrial Microbiology & Biotechnology - Unfortunately, the order of the figures 1-4 has been positioned wrongly in the print published article 相似文献
Poor healing of cutaneous wounds is a common medical problem in the field of traumatology. Due to the intricate pathophysiological processes of wound healing, the use of conventional treatment methods, such as chemical molecule drugs and traditional dressings, have been unable to achieve satisfactory outcomes. Within recent years, explicit evidence suggests that mesenchymal stem cells (MSCs) have great therapeutic potentials on skin wound healing and regeneration. However, the direct application of MSCs still faces many challenges and difficulties. Intriguingly, exosomes as cell-secreted granular vesicles with a lipid bilayer membrane structure and containing specific components from the source cells may emerge to be excellent substitutes for MSCs. Exosomes derived from MSCs (MSC-exosomes) have been demonstrated to be beneficial for cutaneous wound healing and accelerate the process through a variety of mechanisms. These mechanisms include alleviating inflammation, promoting vascularization, and promoting proliferation and migration of epithelial cells and fibroblasts. Therefore, the application of MSC-exosomes may be a promising alternative to cell therapy in the treatment of cutaneous wounds and could promote wound healing through multiple mechanisms simultaneously. This review will provide an overview of the role and the mechanisms of MSC-derived exosomes in cutaneous wound healing, and elaborate the potentials and future perspectives of MSC-exosomes application in clinical practice. 相似文献