Search results for "metabolic engineering"
showing 6 items of 26 documents
Translocation of Zymomonas mobilis pyruvate decarboxylase to periplasmic compartment for production of acetaldehyde outside the cytosol
2019
Abstract Acetaldehyde, a valuable commodity chemical, is a volatile inhibitory byproduct of aerobic fermentation in Zymomonas mobilis and in several other microorganisms. Attempting to improve acetaldehyde production by minimizing its contact with the cell interior and facilitating its removal from the culture, we engineered a Z. mobilis strain with acetaldehyde synthesis reaction localized in periplasm. For that, the pyruvate decarboxylase (PDC) was transferred from the cell interior to the periplasmic compartment. This was achieved by the construction of a Z. mobilis Zm6 PDC‐deficient mutant, fusion of PDC with the periplasmic signal sequence of Z. mobilis gluconolactonase, and the follow…
Current research in biotechnology: Exploring the biotech forefront
2019
Abstract Biotechnology is an evolving research field that covers a broad range of topics. Here we aimed to evaluate the latest research literature, to identify prominent research themes, major contributors in terms of institutions, countries/regions, and journals. The Web of Science Core Collection online database was searched to retrieve biotechnology articles published since 2017. In total, 12,351 publications were identified and analyzed. Over 8500 institutions contributed to these biotechnology publications, with the top 5 most productive ones scattered over France, China, the United States of America, Spain, and Brazil. Over 140 countries/regions contributed to the biotechnology resear…
Biotechnological potential of respiring Zymomonas mobilis: a stoichiometric analysis of its central metabolism.
2013
The active, yet energetically inefficient electron transport chain of the ethanologenic bacterium Zymomonas mobilis could be used in metabolic engineering for redox-balancing purposes during synthesis of certain products. Although several reconstructions of Z. mobilis metabolism have been published, important aspects of redox balance and aerobic catabolism have not previously been considered. Here, annotated genome sequences and metabolic reconstructions have been combined with existing biochemical evidence to yield a medium-scale model of Z. mobilis central metabolism in the form of COBRA Toolbox model files for flux balance analysis (FBA). The stoichiometric analysis presented here sugges…
Kinetic modelling of the Zymomonas mobilis Entner-Doudoroff pathway: insights into control and functionality.
2013
Zymomonas mobilis, an ethanol-producing bacterium, possesses the Entner-Doudoroff (E-D) pathway, pyruvate decarboxylase and two alcohol dehydrogenase isoenzymes for the fermentative production of ethanol and carbon dioxide from glucose. Using available kinetic parameters, we have developed a kinetic model that incorporates the enzymic reactions of the E-D pathway, both alcohol dehydrogenases, transport reactions and reactions related to ATP metabolism. After optimizing the reaction parameters within likely physiological limits, the resulting kinetic model was capable of simulating glycolysis in vivo and in cell-free extracts with good agreement with the fluxes and steady-state intermediate …
Metabolic Profiling of Glucose-Fed Metabolically Active Resting Zymomonas mobilis Strains
2020
Zymomonas mobilis is the most efficient bacterial ethanol producer and its physiology is potentially applicable to industrial-scale bioethanol production. However, compared to other industrially important microorganisms, the Z. mobilis metabolome and adaptation to various nutritional and genetic perturbations have been poorly characterized. For rational metabolic engineering, it is essential to understand how central metabolism and intracellular redox balance are maintained in Z. mobilis under various conditions. In this study, we applied quantitative mass spectrometry-based metabolomics to explore how glucose-fed non-growing Z. mobilis Zm6 cells metabolically adapt to change of oxygen avai…
Enhanced fermentative capacity of yeasts engineered in storage carbohydrate metabolism.
2014
During yeast biomass production, cells are grown through several batch and fed-batch cultures on molasses. This industrial process produces several types of stresses along the process, including thermic, osmotic, starvation, and oxidative stress. It has been shown that Saccharomyces cerevisiae strains with enhanced stress resistance present enhanced fermentative capacity of yeast biomass produced. On the other hand, storage carbohydrates have been related to several types of stress resistance in S. cerevisiae. Here we have engineered industrial strains in storage carbohydrate metabolism by overexpressing the GSY2 gene, that encodes the glycogen synthase enzyme, and deleting NTH1 gene, that …