Characterization of Single Cell Protein produced by Cupriavidus necator grown on various nitrogen and carbon sources.

Microorganisms can serve as Single Cell Proteins (SCP) used as an alternative and non-conventional protein source to meet the protein shortage and increasing demand. The objective of this research was to characterize growth and biomass composition of the bacterium Cupriavidus necator, cultivated on various nitrogen (ammonium sulfate and urea) and carbon (glucose, formic acid and oleic acid) sources. Under well-controlled conditions, a mono-factorial approach was employed to study the impact of the nature of the substrates on biomass growth and composition in bioreactors.

Isopropanol production from carbon dioxide by using a zero-gap cell with culture broth as catholyte.

Microbial CO fixation is a promising route for sustainable chemical production. The facultative chemolithoautotroph can convert CO into value-added compounds using H and O. Here, we developed a bioelectrochemical system (BES) for isopropanol production that integrates CO fixation with H generation via a zero-gap proton exchange membrane electrolyzer.

Cupriavidus necator as a model organism for CO-based biotechnology.

Cupriavidus necator H16 is a chemolithoautotrophic model organism that can grow in a simple mineral medium supplemented with the gases H, O and CO. This unique metabolic capability makes it a promising organism for sustainable biotechnology applications such as the production of bioplastics, single cell proteins and bulk chemicals from renewable resources. However, gas fermentation, particularly with explosive gas mixtures like H and O, poses considerable technical and safety challenges.

Conceptual Approach for Aerobic Autotrophic Gas Cultivation in Shake Flasks: Overcoming the Inhibitory Effects of Oxygen in Cupriavidus necator.

This study conceptualizes the design of a small-scale system (250 mL-1 L) for the autotrophic cultivation of hydrogen-oxidizing bacteria, such as the representative strain Cupriavidus necator. The research aimed to systematically investigate the impact of bottle volume and gas composition, particularly oxygen concentration, on the growth and performance of C. necator during autotrophic cultivations.

Identification and monitoring of cell heterogeneity from plasmid recombination during limonene production.

Detecting alterations in plasmid structures is often performed using conventional molecular biology. However, these methods are laborious and time-consuming for studying the conditions inducing these mutations, which prevent real-time access to cell heterogeneity during bioproduction. In this work, we propose combining both flow cytometry and fluorescence-activated cell sorting, integrated with mechanistic modelling to study conditions that lead to plasmid recombination using a limonene-producing microbial system as a case study.

F-Fluorination of Nitroimidazolyl-Containing Sultone: A Direct Access to a Highly Hydrophilic Radiotracer for High-Performance Positron Emission Tomography Imaging of Hypoxia.

Hypoxia, characterized by nonphysiological levels of oxygen tension, is a key phenomenon common to the majority of malignant tumors with poor prognosis. Many efforts have been made to develop hypoxia imaging for diagnosis, staging, and monitoring of diseases, as well as for evaluating therapies. PET Imaging using F-fluoronitroimidazoles (i.

Impact of the environmental parameters on single cell protein production and composition by Cupriavidus necator.

Due to the rapid increase in the world's population, many developing countries are facing malnutrition problems, including famine and food insecurity. Particularly, the deficiency of protein sources becomes a serious problem for human and animal nutrition. In this context, Single Cell Proteins, could be exploited as an alternative source of unconventional proteins.

Autotrophic Production of the Sesquiterpene α-Humulene with in a Controlled Bioreactor.

is a facultative chemolithotrophic organism that grows under both heterotrophic and autotrophic conditions. It is becoming increasingly important due to its ability to convert CO into industrially valuable chemicals. To translate the potential of into technical applications, it is necessary to optimize and scale up production processes.

Comparison of plasmid stabilization systems during heterologous isopropanol production in fed-batch bioreactor.

Strain robustness during production of recombinant molecules is of major interest to ensure bioprocess profitability. The heterogeneity of populations has been shown in the literature as a source of instability in bioprocesses. Thus, the heterogeneity of the population was studied by evaluating the robustness of the strains (stability of plasmid expression, cultivability, membrane integrity and macroscopic cell behavior) during well-controlled fedbatch cultures.

Co-expression of an isopropanol synthetic operon and eGFP to monitor the robustness of Cupriavidus necator during isopropanol production.

Phenotypic heterogeneity in bioprocesses is suspected to reduce performances, even in case of monoclonal cultures. Here, robustness of an engineered isopropanol-overproducing strain and heterogeneity of its plasmid expression level were evaluated in fed-batch cultures. Previously, eGFP was identified as a promising plasmid expression reporter for C.

Study of plasmid-based expression level heterogeneity under plasmid-curing like conditions in Cupriavidus necator.

Plasmid expression level heterogeneity in Cupriavidus necator was studied in response to stringent culture conditions, supposed to enhance plasmid instability, through plasmid curing strategies. Two plasmid curing strategies were compared based on their efficiency at generating heterogeneity in batch: rifampicin addition and temperature increase. A temperature increase from 30° to 37 °C was the most efficient plasmid curing strategy.

Investigation of the robustness of Cupriavidus necator engineered strains during fed-batch cultures.

It is of major interest to ensure stable and performant microbial bioprocesses, therefore maintaining high strain robustness is one of the major future challenges in industrial microbiology. Strain robustness can be defined as the persistence of genotypic and/or phenotypic traits in a system. In this work, robustness of an engineered strain is defined as plasmid expression stability, cultivability, membrane integrity and macroscopic cell behavior and was assessed in response to implementations of sugar feeding strategies (pulses and continuous) and two plasmid stabilization systems (kanamycin resistance and Post-Segregational Killing hok/sok).

Accelerostat study in conventional and microfluidic bioreactors to assess the key role of residual glucose in the dimorphic transition of Yarrowia lipolytica in response to environmental stimuli.

Yarrowia lipolytica, with a diverse array of biotechnological applications, is able to grow as ovoid yeasts or filamentous hyphae depending on environmental conditions. This study has explored the relationship between residual glucose levels and dimorphism in Y. lipolytica.

Insights into Clostridium tetani: From genome to bioreactors.

Tetanus vaccination is of major importance for public health in most countries in the world. The World Health Organization indicated that 15,000 tetanus cases were reported in 2018 (Organization, World Health, 2019). Currently, vaccine manufacturers use tetanus toxin produced by Clostridium tetani fermentation in complex media.

Plasmid expression level heterogeneity monitoring via heterologous eGFP production at the single-cell level in Cupriavidus necator.

A methodology for plasmid expression level monitoring of eGFP expression suitable for dynamic processes was assessed during fermentation. This technique was based on the expression of a fluorescent biosensor (eGFP) encoded on a recombinant plasmid coupled to single-cell analysis. Fluorescence intensity at single-cell level was measured by flow cytometry.

Nutritional, biochemical and microbiological composition of Mart. sap in Burkina Faso.

The palmyra palm Mart. grow wild and gives natural stands in several localities of central-eastern and eastern regions of Burkina Faso. This work aimed to determine the nutritional, biochemical and microbiological composition of fresh palm sap from Mart.

[F]Fludarabine-PET as a promising tool for differentiating CNS lymphoma and glioblastoma: Comparative analysis with [F]FDG in human xenograft models.

This paper investigated whether positron emission tomography (PET) imaging with [F]fludarabine ([F]FDB) can help to differentiate central nervous system lymphoma (CNSL) from glioblastoma (GBM), which is a crucial issue in the diagnosis and management of patients with these aggressive brain tumors. Multimodal analyses with [F]fluorodeoxyglucose ([F]FDG), magnetic resonance imaging (MRI) and histology have also been considered to address the specificity of [F]FDB for CNSL. Nude rats were implanted with human MC116 lymphoma-cells (n = 9) or U87 glioma-cells (n = 4).

Alka(e)ne synthesis in Cupriavidus necator boosted by the expression of endogenous and heterologous ferredoxin-ferredoxin reductase systems.

To boost aldehyde deformylating oxygenase (ADO) activity in a Cupriavidus necator strain expressing a synthetic alkane pathway, the expression of two ferredoxin-ferredoxin reductase systems was tested. The genes of a native fd/FNR-like system were identified in C. necator and expressed in a previously engineered alka(e)ne producing strain.