Ray, S. K. — Page 2 | bioRxiv Science

bioRxiv2021

Nanoceutical Fabric Prevents COVID-19 Spread through Expelled Respiratory Droplets: A Combined Computational, Spectroscopic and Anti-microbial Study

Centers for Disease Control and Prevention (CDC) warns the use of one-way valves or vents in free masks for potential threat of spreading COVID-19 through expelled respiratory droplets. Here, we have developed a nanoceutical cotton fabric duly sensitized with non-toxic zinc oxide nanomaterial for potential use as membrane filter in the one way valve for the ease of breathing without the threat of COVID-19 spreading. A detailed computational study revealed that zinc oxide nanoflowers (ZnO NF) with almost two-dimensional petals trap SARS-CoV-2 spike proteins, responsible to attach to ACE-2 receptors in human lung epithelial cells. The study also confirm significant denaturation of the spike proteins on the ZnO surface, revealing removal of virus upon efficient trapping. Following the computational study, we have synthesized ZnO NF on cotton matrix using hydrothermal assisted strategy. Electron microscopic, steady-state and picosecond resolved spectroscopic studies confirm attachment of ZnO NF to the cotton (i.e., cellulose) matrix at atomic level to develop the nanoceutical fabric. A detailed antimicrobial assay using Pseudomonas aeruginosa bacteria (model SARS-CoV-2 mimic) reveals excellent anti-microbial efficiency of the developed nanoceutical fabric. To our understanding the novel nanoceutical fabric used in one-way valve of a face mask would be the choice to assure breathing comfort along with source control of COVID-19 infection. The developed nanosensitized cloth can also be used as antibacterial/anti CoV-2 washable dress material in general. GRAPHICAL ABSTRACT O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY A novel nanoceutical cotton fabric duly sensitized with non-toxic zinc oxide nanoflower can potentially be used as membrane filter in the one way valve of face mask to assure breathing comfort along with source control of COVID-19 infection. The nanoceutical fabric denatures the SARS-CoV-2 spike protein and makes the microorganism ineffective.

microbiology↗

bioRxiv2020

Entner-Doudoroff pathway and Non-OxPPP bypasses glycolysis and OxPPP in Ralstonia solanacearum

In Ralstonia solanacearum, a devastating phytopathogen whose metabolism is poorly understood, we observed that Entner-Doudoroff (ED) pathway and NonOxidative pentose phosphate pathway (OxPPP) bypasses glycolysis and OxPPP under glucose oxidation. Evidences derived from 13C stable isotopes feeding and genome annotation based comparative metabolic network analysis supported the observations. Comparative metabolic network analysis derived from the currently available 53 annotated R. solanacearum strains also including the recently reported strain (F1C1), representing the four phylotypes confirmed the lack of key genes coding for phosphofructokinase (pfk-1) and phosphogluconate dehydrogenase (gnd) enzymes that are relevant for glycolysis and OxPPP respectively. R. solanacearum F1C1 cells fed with 13C Glucose (99%[1-13C]- or 99%[1,2-13C]- or 40%[13C6]-glucose) followed by GC-MS based labelling analysis of fragments from amino acids, glycerol and ribose provided clear evidence that rather than Glycolysis and OxPPP, ED pathway and NonOxPPP are the main routes sustaining metabolism in R. solanacearum. The 13C incorporation in the mass ions of alanine (m/z 260, m/z 232); valine (m/z 288, m/z 260), glycine (m/z 218), serine (m/z 390, m/z 362), histidine (m/z 440, m/z 412), tyrosine (m/z 466, m/z 438), phenylalanine (m/z 336, m/z 308), glycerol (m/z 377) and ribose (m/z 160) mapped the pathways supporting the observations. The outcomes help better defining the central carbon metabolic network of R. solanacearum that can be integrated with 13C metabolic flux analysis as well as flux balance analysis studies for defining the metabolic phenotypes. ImportanceUnderstanding the metabolic versatility of Ralstonia solanacearum is important as it regulates the tradeoff between virulence and metabolism (1, 2) in a wide range of plant hosts. Due to a lack of clear evidence until this work, several published research papers reported on potential roles of Glycolysis and Oxidative pentose phosphate pathways (OxPPP) in R. solanacearum (3, 4). This work provided evidence from 13C stable isotopes feeding and genome annotation based comparative metabolic network analysis that Entner-Doudoroff pathway and Non-OxPPP bypasses glycolysis and OxPPP during the oxidation of Glucose, one of the host xylem pool that serves as a potential carbon source (5). The outcomes help better defining the central carbon metabolic network of R. solanacearum that can be integrated with 13C metabolic flux analysis as well as flux balance analysis studies for defining the metabolic phenotypes. The study highlights the need to critically examine phytopathogens whose metabolism is poorly understood.

systems biology↗