The activity of the enzymes of the central metabolic pathways has been the subject of intensive analysis; however, the Entner-Doudoroff (ED) pathway has only recently begun to attract attention. The metabolic response to edd gene knockout in Escherichia coli JM101 and PTS- Glc+ was investigated in gluconate and glucose batch cultures and compared with other pyruvate kinase and PTS mutants previously constructed. Even though the specific growth rates between the strain carrying the edd gene knockout and its parent JM101 and PTS- Glc+ edd and its parent PTS- Glc+ were very similar, reproducible changes in the specific consumption rates and biomass yields were obtained when grown on glucose. These results support the participation of the ED pathway not only on gluconate metabolism but on other metabolic and biochemical processes in E. coli. Despite that gluconate is a non-PTS carbohydrate, the PTS- Glc+ and derived strains showed important reductions in the specific growth and gluconate consumption rates. Moreover, the overall activity of the ED pathway on gluconate resulted in important increments in PTS- Glc+ and PTS- Glc+ pykF mutants. Additional results obtained with the pykA pykF mutant indicate the important contribution of the pyruvate kinase enzymes to pyruvate synthesis and energy production in both carbon sources.
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http://dx.doi.org/10.1139/w05-101 | DOI Listing |
mSphere
December 2024
State Key Laboratory of Vaccines for Infectious Diseases, Xiang-An Biomedicine Laboratory, Department of Laboratory Medicine, School of Public Health, Xiamen University, Xiamen, Fujian Province, China.
Int J Biol Macromol
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Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China; Key Laboratory of Diseases Controlling for Aquatic Economic Animals of Guangdong Higher Education Institutions, College of Fishery, Guangdong Ocean University, Zhanjiang 524088, China. Electronic address:
Cyclic AMP (cAMP) and cAMP receptor protein (CRP) system controls catabolic enzyme expression based on metabolite concentrations in bacteria. Hemolysin co-regulatory protein (Hcp) is well known as a molecular chaperone for virulence factor secretion of the type VI secretion system (T6SS). However, the intracellular role of Hcp involving in bacterial physiological processes remains unknown.
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November 2024
State Key Laboratory of Food Nutrition &Safety, Tianjin University of Science and Technology, Tianjin 300457, PR China; Key Laboratory of Industrial Fermentation Microbiology (Ministry of Education), Tianjin University of Science and Technology, Tianjin 300457, PR China.
Bacterial cellulose (BC) is a renewable biomaterial that has attracted significant attention due to its excellent properties and wide applications. Komagataeibacter xylinus CGMCC 2955 is an important BC-producing strain. It primarily produces BC from glucose while simultaneously generating gluconic acid as a by-product, which acidifies the medium and inhibits BC synthesis.
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Department of Molecular Science and Technology, Ajou University, Suwon, Republic of Korea.
Salmonella enterica serovar Typhimurium is an enteric pathogen spreading via the fecal-oral route. Transmission across humans, animals, and environmental reservoirs has forced this pathogen to rapidly respond to changing environments and adapt to new environmental conditions. Cyclic di-GMP (c-di-GMP) is a second messenger that controls the transition between planktonic and sessile lifestyles, in response to environmental cues.
View Article and Find Full Text PDFJ Agric Food Chem
November 2022
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
Fucosyllactose (FL) has garnered considerable attention for its benefits on infant health. In this study, we report an efficient cell factory to produce 2'/3-fucosyllactose (2'/3-FL) with lactose pathway through metabolic network remodeling, including (1) modification of the PTS system to enhance glucose internalization efficiency; (2) screening for β-1,4-galactosyltransferase (β-1,4-GalT) and introduction of lactose synthesis pathway; (3) eliminating inhibition of byproduct pathways; (4) constructing antibiotic-free and inducer-free FL strains; and (5) up-regulating the expression of genes in the GDP-l-fucose module. The final engineered strains BP10-3 and BP11-3 produced 4.
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