Background: Two variants of Methylobacterium extorquens AM1 demonstrated a trade-off between growth rate and biomass yield. In addition, growth rate and biomass yield were also affected by supplementation of growth medium with different amounts of cobalt. The metabolism changes relating to these growth phenomena as well as the trade-off were investigated in this study. (13)C metabolic flux analysis was used to generate a detailed central carbon metabolic flux map with both absolute and normalized flux values.
Results: The major differences between the two variants occurred at the formate node as well as within C3-C4 inter-conversion pathways. Higher relative fluxes through formyltetrahydrofolate ligase, phosphoenolpyruvate carboxylase, and malic enzyme led to higher biomass yield, while higher relative fluxes through pyruvate kinase and pyruvate dehydrogenase led to higher growth rate. These results were then tested by phenotypic studies on three mutants (null pyk, null pck mutant and null dme mutant) in both variants, which agreed with the model prediction.
Conclusions: In this study, (13)C metabolic flux analysis for two strain variants of M. extorquens AM1 successfully identified metabolic pathways contributing to the trade-off between cell growth and biomass yield. Phenotypic analysis of mutants deficient in corresponding genes supported the conclusion that C3-C4 inter-conversion strategies were the major response to the trade-off.
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http://dx.doi.org/10.1186/s12866-016-0778-4 | DOI Listing |
PeerJ
January 2025
College of Science & Engineering and Centre for Tropical Environmental and Sustainability Science, James Cook University of North Queensland, Cairns, Queensland, Australia.
Ozone (O), a major air pollutant, can negatively impact plant growth and yield. While O impacts have been widely documented in crops such as wheat and soybean, few studies have looked at the effects of O on sorghum, a C plant and the fifth most important cereal crop worldwide. We exposed grain sorghum ( cv.
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January 2025
Department of Biology, School of Philosophy, Science and Literature (FFCLRP), University of São Paulo, Ribeirão Preto, Brazil.
This study aimed to compare the conventional soybean ( L.) cultivation method with integrated systems in an Latossolo Vermelho Acriférrico típico and how these systems affect soil cover biomass production, initial nutrient concentration in plant residues, soil respiration and microclimate, as well as soybean growth, physiology and productivity. A comparative analysis of microclimate and soil respiration, plant physiology, and growth was conducted between a conventional soybean monoculture (soybean grown without plant residues on the soil from the previous crop) and soybean grown in soil containing maize residues.
View Article and Find Full Text PDFOrg Lett
January 2025
Key Laboratory of Environment-Friendly Composite Materials of the State Ethnic Affairs Commission, Key Laboratory for Utility of Environment-Friendly Composite Materials and Biomass in University of Gansu Province, College of Chemical Engineering, Northwest Minzu University, Lanzhou 730030, P. R. China.
An efficient phospha-aldol/Meyer-Schuster rearrangement cascade reaction between propargylic aldehydes and phosphine oxides has been developed in which various phosphoryl enones were obtained in moderate to excellent yields. A comprehensive series of mechanistic experiments, including the identification of key intermediates and the application of O isotope labeling, has confirmed that this cascade reaction proceeds through a phospha-aldol followed by Meyer-Schuster rearrangement cascade reaction.
View Article and Find Full Text PDFFood Res Int
February 2025
Food Science and Nutrition Department, University of Minnesota, 1334 Eckles Ave, Saint Paul, MN, 55108, United States. Electronic address:
There is an ever-increasing demand for novel plant proteins that are non-allergenic, nutritionally complete, adequately functional, and can be sustainably sourced. RuBisCo is a protein that fulfills these requirements and can be sourced from alfalfa (Medicago sativa). Therefore, this study investigated several techniques to adequately extract alfalfa protein.
View Article and Find Full Text PDFFood Res Int
February 2025
Department of Chemistry and Chemical Engineering, State Key Laboratory of Efficient Production of Forest Resources, Engineering Research Center of Forestry Biomass Materials and Bioenergy (Ministry of Education), Beijing Forestry University, Beijing 100083, China. Electronic address:
Galactomannan comes from a wide range of plant resources and has some biological activities, but its bioavailability is limited due to its large molecular weight and complex structure. In this study, three degradation methods (HO, ultrasound, and β-mannanase) combined with ethanol fractional precipitation (25 %, 50 %, and 75 %) were used to degrade and separate Gleditsia sinensis galactomannans (GSG), and the physicochemical properties and biological activities of GSG after degradation were analyzed. Comprehensive comparison indicates that HO exhibits had a better degradation effect.
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