Analysis of the expression of the Herbaspirillum seropedicae nifA promoter in Escherichia coli and Herbaspirillum seropedicae, showed that nifA expression is primarily dependent on NtrC but also required NifA for maximal expression under nitrogen-fixing conditions. Deletion of the IHF (integration host factor)-binding site produced a promoter with two-fold higher activity than the native promoter in the H. seropedicae wild-type strain but not in a nifA strain, indicating that IHF controls NifA auto-activation. IHF is apparently required to prevent overexpression of the NifA protein via auto-activation under nitrogen-fixing conditions in H. seropedicae.
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http://dx.doi.org/10.1111/j.1574-6968.2002.tb11263.x | DOI Listing |
Arch Microbiol
October 2024
Laboratorio de Microbiología Molecular, Departamento de Bioquímica y Genómica Microbianas, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, Montevideo, 11600, Uruguay.
D-xylose, one of the most abundant sugars in lignocellulosic biomass, is not widely used to produce bioproducts with added value, in part due to the absence of industrial microorganisms able to metabolize it efficiently. Herbaspirillum seropedicae Z69 is a β-proteobacterium able to accumulate poly-3-hydroxybutyrate, a biodegradable thermoplastic biopolymer, with contents higher than 50%. It metabolizes D-xylose by non-phosphorylative pathways.
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August 2024
Department of Food Chemistry and Biocatalysis, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
Flavin-dependent monooxygenases (FMOs) are a valuable group of biocatalysts that can regioselectively introduce a hydroxy group for the targeted modification of biologically active compounds. Here, we present the fdeE, the FMO from Herbaspirillum seropedicae SmR1 that is a part of the naringenin degradation pathway and is active towards a wide range of flavonoids-flavanones, flavones, isoflavones, and flavonols. Bioinformatics and biochemical analysis revealed a high similarity between the analyzed enzyme and other F8H FMOs what might indicate convergent evolutionary mechanism of flavonoid degradation pathway emergence by microorganism.
View Article and Find Full Text PDFArch Microbiol
June 2024
Department of Biochemistry and Molecular Biology, Universidade Federal do Paraná, Curitiba, PR, Brazil.
The RNA-Seq profiling of Herbaspirillum seropedicae SmR1 wild-type and ntrC mutant was performed under aerobic and three nitrogen conditions (ammonium limitation, ammonium shock, and nitrate shock) to identify the major metabolic pathways modulated by these nitrogen sources and those dependent on NtrC. Under ammonium limitation, H. seropedicae scavenges nitrogen compounds by activating transporter systems and metabolic pathways to utilize different nitrogen sources and by increasing proteolysis, along with genes involved in carbon storage, cell protection, and redox balance, while downregulating those involved in energy metabolism and protein synthesis.
View Article and Find Full Text PDFCureus
May 2024
Internal Medicine, St. Luke's University Health Network, Chesterfield, USA.
is a species of bacteria commonly found in vegetation, but in rare cases, can cause opportunistic infections in human hosts. Infections typically occur due to environmental exposure to the pathogen, such as through agriculture or gardening. However, these incidents typically only involve immunocompromised patients.
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April 2024
Federal University of Espírito Santo, Department of Agronomy, Alto Universitário, s/n, Guararema, 29.500-000, Alegre, ES, Brazil.
Edaphic factors can modulate the effects of microbial inoculants on crop yield promotion. Given the potential complexity of microbial inoculant responses to diverse soil management practices, we hypothesize that sustainable management of soil and water irrigation may improve soil quality and enhance the effects of plant growth-promoting bacteria (PGPB). Consequently, the primary objective was to assess the effectiveness of microbial inoculants formulated with (Hs) and (Ab) on maize growth in soils impacted by different historical conservation management systems.
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