Brno University of Technology

About: Brno University of Technology is a education organization based out in Brno, Czechia. It is known for research contribution in the topics: Fracture mechanics & Filter (video). The organization has 6339 authors who have published 15226 publications receiving 194088 citations. The organization is also known as: Vysoké učení technické v Brně & BUT.

High-Performance Ammonia Gas Sensors Based on Plasma Treated Carbon Nanostructures

Abstract: Sensors based on multi-walled carbon nanotubes were functionalized by oxygen plasma treatment and plasma co-polymerization of maleic anhydride and acetylene, obtaining core-shell carbon nanopartices covered by functional groups. The active nanostructured carbonaceous material was investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. It was confirmed that plasma treatment increases the content of surface functional groups. The sensing properties of the functionalized material were measured in the range of 10–1000 ppm of NH3 at room temperature. The plasma treated sensor showed an extremely high response of 22.5%, 27.9%, and 31.4% to 100 ppm, 250 ppm, and 500 ppm of NH3, respectively. It was shown that the nature of NH3 adsorption on the surface of functionalized nanostructured carbon material is physical adsorption.

Application of random mutagenesis to enhance the production of polyhydroxyalkanoates by Cupriavidus necator H16 on waste frying oil

Abstract: Using random chemical mutagenesis we obtained the mutant of Cupriavidus necator H16 which was capable of improved (about 35 %) production of poly(3-hydroxybuytrate) (PHB) compared to the wild-type strain The mutant exhibited significantly enhanced specific activities of enzymes involved in oxidative stress response such as malic enzyme, NADP-dependent isocitrate dehydrogenase, glucose-6-phosphate dehydrogenase and glutamate dehydrogenase Probably, due to the activation of these enzymes, we also observed an increase of NADPH/NADP⁺ ratio It is likely that as a side effect of the increase of NADPH/NADP⁺ ratio the activity of PHB biosynthetic pathway was enhanced, which supported the accumulation of PHB Furthermore, the mutant was also able to incorporate propionate into copolymer poly(3-hydroxybuytyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] more efficiently than the wild-type strain (Y3HV/prec = 017 and 029 for the wild-type strain and the mutant, respectively)) We assume that it may be caused by lower availability of oxaloacetate for the utilization of propionyl-CoA in 2-methylcitrate cycle due to increased action of malic enzyme Therefore, propionyl-CoA was incorporated into copolymer rather than transformed to pyruvate via 2-methylcitrate cycle Thus, the mutant was capable of the utilization of waste frying oils and the production of P(3HB-co-3HV) with better yields and improved content of 3HV resulting in better mechanical properties of copolymer than the wild-type strain The results of this work may be used for the development of innovative fermentation strategies for the production of PHA and also it might help to define novel targets for the genetic manipulations of PHA producing bacteria