Characteristics of selenium nanoparticles synthesized by cell-free supernatant Cupriavidus sp. SHE / 生物工程学报

In recent years, selenium nanoparticles (SeNPs) have been widely used in many fields such as nanotechnology, biomedicine and environmental remediation due to their good electrical conductivity, photothermal properties and anticancer properties. In this study, the cell-free supernatant, whole cell and the cell-free extracts of the strain Cupriavidus sp. SHE were used to synthesize SeNPs, and several methods were applied to analyze the crystal structure and surface functional groups of the nanoparticles. Finally, Pseudomonas sp. PI1 (G⁺) and Escherichia coli BL21 (G⁻) were selected to investigate the antibacterial properties of SeNPs. Cell-free supernatant, whole cell and cell-free extracts of the strain could synthesize SeNPs. As for the cell-free supernatant, selenite concentration of 5 mmol/L and pH=7 were favorable for the synthesis of SeNPs. TEM images show that the average size of nanospheres synthesized by the supernatant was 196 nm. XRD analysis indicates the hexagonal crystals structure of SeNPs. FTIR and SDS-PAGE confirmed the proteins bound to the surfaces of SeNPs. SeNPs synthesized by cell-free supernatant showed no antimicrobial activities against Pseudomonas sp. PI1 and Escherichia coli BL21 (DE3). These results suggest that proteins played an important role in biotransformation of SeNPs in an eco-friendly process, and SeNPs synthesized in this study were non-toxic and biologically compatible, which might be applied in other fields in the future.

Cellulitis Caused by a Novel Cupriavidus Species Strain J1218 Identified by Whole Genome Sequencing / 대한임상미생물학회지

We report a case of cellulitis caused by a novel Cupriavidus species identified using whole-genome sequence analysis. Subcutaneous tissue biopsies from the left lower leg of a 67-year-old man who suffered from cellulitis were cultured. Round, convex, gray and non-hemolytic colonies were recovered after 72-h incubation. 16S rRNA sequence analysis showed 98.6% similarity with Cupriavidus basilensis DSM 11853(T) in the NCBI database and 99.9% similarity with C. basilensis KF708 in the EzBioCloud database. Genomic analysis using the MiSeq platform (Illumina, USA) and the TrueBac ID database (ChunLab, Korea) revealed that the average nucleotide identity (ANI) of this strain with C. basilensis DSM 11853(T) was 87.6%. The patient was treated with oral cefditoren pivoxil for 9 weeks. This study is the first to report cellulitis caused by Cupriavidus species strain J1218.

Isolation and 2,4-D-degrading characteristics of Cupriavidus campinensis BJ71

An indigenous bacterial strain capable of utilizing 2,4-dichlorophenoxyacetic acid as the sole carbon and energy source was isolated from a soil used for grown wheat with a long-term history of herbicide use in Beijing, China. The strain BJ71 was identified as Cupriavidus campinensis based on its 16S rRNA sequence analysis and morphological, physiological, and biochemical characteristics. The degradation characteristics of strain BJ71 were evaluated. The optimal conditions for 2,4-D degradation were as follows: pH 7.0, 30 °C, 3% (v/v) inoculum size, and an initial 2,4-D concentration of 350 mg L−1. Up to 99.57% of the 2,4-D was degraded under optimal conditions after 6 days of incubation. Strain BJ71 was also able to degrade quizalofop and fluroxypyr. This is the first report of a 2,4-D-degrader containing tfdA gene that can utilize these two herbicides. In a biodegradation experiment, 87.13% and 42.53% of 2,4-D (initial concentration, 350 mg kg−1) was degraded in non-sterile and sterilized soil inoculated with BJ71, respectively, after 14 days. The 2,4-D degradation was more rapid in a soil microcosm including BJ71 than in a soil microcosm without BJ71. These results indicate that strain BJ71 is a potential candidate for the bioremediation of soil contaminated with the herbicide 2,4-D.

Cupriavidus pauculus (Ralstonia paucula) concomitant meningitis and septicemia in a neonate: First case report from India.

Ralstonia paucula (formerly classifi ed as CDC (Centre for Disease Control) group IVc-2, Wautersia paucula; recently renamed as Cupriavidus pauculus) is an environmental Gram-negative bacillus isolated from water sources and can cause serious human infections. Patients recover bacteriologically indicating low virulence. A total of 32 cases have been reported world-wide, but no isolation has ever been reported from cerebrospinal fl uid or in India. The fi rst case of R. paucula meningitis and septicemia is being reported here along with the brief summary of cases reported world-wide.

Biosynthesis of P(3HB-co-3HV-co-3HHp) terpolymer by Cupriavidus necator PHB4 transformant harboring the highly active PHA synthase gene of Chromobacterium sp. USM2

Aims: This study evaluates potentials of Cupriavidus necator PHB4 transformant harboring the highly active polyhydroxyalkanoate synthase gene (phaC) of a locally isolated Chromobacterium sp. USM2 for its ability to incorporate 3-hydroxyheptanoate (3HHp) monomer. Methodology and results: A mixture of fructose and sodium heptanoate fed to the culture gave rise to poly(3- hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyheptanoate), [P(3HB-co-3HV-co-3HHp)] terpolymer synthesis, with traces of 3HHp monomers confirmed through gas chromatography (GC), proton (1H) and carbon (13C) NMR spectra. Conclusion, significance and impact of study: This study has revealed that the PHA synthase of Chromobacterium sp. USM2 has a broad range of substrate specificity. The synthase is able to polymerize 3-hydroxyalkanoate monomers having 4–7 carbon atoms.

Waste cooking oil as substrate for biosynthesis of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate): Turning waste into a value-added product

Aims: Improper disposal of domestic wastes, such as waste cooking oil (WCO), contributes to the deterioration of the environment and may lead to health problems. In this study, we evaluated the potential of plant-based WCO as a carbon source for the commercial biosynthesis of the bio-plastics, poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate). The consumption of WCO for this purpose would mitigate their pollution of the environment at the same time. Methodology and Results: WCO collected from several cafeterias in USM was tested as the carbon source for polyhydroxyalkanoates (PHA) production. A selection of suitable nitrogen source was first conducted in order to obtain an acceptable number of dry cell weight (DCW) and PHA content. Urea was found to be a suitable nitrogen source for the two bacterial strains used in our study, Cupriavidus necator H16 and its transformed mutant, C. necator PHB¯4 harboring the PHA synthase gene of Aeromonas caviae (PHB¯4/pBBREE32d13). With WCO as the sole carbon source, C. necator H16 yielded a relatively good dry cell weight (DCW=25.4 g/L), with 71 wt% poly(3-hydroxybutyrate) P(3HB) content. In comparison, the DCW obtained with fresh cooking oil (FCO) was 24.8 g/L. The production of poly(3 hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] from WCO by the transformant C. necator PHB¯4 was comparable, yielding a DCW of 22.3 g/L and P(3HB-co-3HHx) content of 85 wt%. Lipase activities for both bacterial strains reached a maximum after 72 h of cultivation when time profile was conducted. Conclusion, significance and impact of study: The use of WCO as a carbon source in the biosynthesis of the bioplastic, PHA, turns a polluting domestic waste into a value-added biodegradable product. This renewable source material can thus be exploited for the low cost production of PHA.

Bacteriemia asociada a catéter por Cupriavidus pauculus / Cupriavidus pauculus catheter related bacteremia

Cupriavidus pauculus es un bacilo Gram negativo con metabolismo oxidativo, que se ha aislado de muestras de agua y suelo, pero raramente de personas como entidad clínica. En la literatura científica existen menos de veinte artículos de reportes de caso de este microorganismo. La mayoría han sido pacientes con algún tipo de inmunosupresión, sometidos a procedimientos invasivos, especialmente de tipo vascular, y que han requerido múltiple manejo antibiótico. Cupriavidus pauculus ha mostrado baja virulencia y sensibilidad antibiótica, principalmente a trimetoprim-sulfametoxazol, betalactámicos de amplio espectro y quinolonas. Se presenta el caso de una paciente de 55 años con antecedentes de trasplante renal, que ingresó con infección de tejidos blandos y a quien se le diagnosticó bacteriemia asociada a catéter por C. pauculus durante la hospitalización.

Cupriavidus pauculus it’s a gram-negative bacillus with an oxidative metabolism that has been isolated in water and soil samples, but rarely in people clinical entities. There are less than 20 articles case-reported about this microorganism. Most of which have been patients with some type of immune impairment, mostly subjects with invasive vascular procedures, who had required multiples antibiotic management. Cupriavidus pauculus has mainly shown a low virulence and antibiotic sensibility to trimethoprim-sulfametoxazol, broad spectrum betalactamics and quinolones. As presented in the case of a 55 year old patient with renal transplantation history admitted with a soft tissue infection and diagnosed with a catheter associated bacteremia by C. pauculus, during hospitalization.