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The paper presents the results of a study on the sensitivity of gas-sensing zinc oxide ZnO film nanostructures at room temperature. The aim of the research was to investigate the effect of ambient humidity on the conductivity of ZnO samples and their response to ethanol vapor in the presence of water vapor. It has been discovered that zinc oxide films are responsive to both water and ethanol vapor at room temperature, across a broad range of concentrations (5% to 50% saturated vapor). The study found that repeated exposure to water vapor can lead to changes in the conductivity of zinc oxide samples when they are exposed to dry air. Additionally, pre-annealing the samples at 400°C can help to replicate the concentration-dependent response of gas-sensitive structures to water vapor. Hysteresis was observed in the relationship between concentration and response to water vapor, in the range of 5% to 90% of the relative humidity. This can be explained by the capillary condensation of water vapor within the mesopores of zinc oxide layers. As the humidity of a gas sample containing ethanol increased, the response values and detection limit for ethanol decreased in the gas-air mixture for ZnO samples. Statistical analysis using the principal component method showed the potential for classifying dry and humid gas samples with ethanol vapor in air. Data processing was used to eliminate the influence of the background humidity on the calibration curve for gas-sensitive ZnO samples, demonstrating the effectiveness of this method.

Semiconducting nanomaterials with different size and shape have widely applications in the field of electronics, a key pathway to improve their performance is by recombination of different materials. In the present study, Ti3C2TX MXene derivative coupled with NiO nanodisk were prepared via simple hydrothermal and annealing treatment. The prepared samples were characterized by XRD, XPS, SEM, EDS and some other testing methods. The samples were made into sensors and the gas sensing properties of the materials were investigated under different test conditions, which show that the ethanol response value (14.68) of N/M-2 sensor are approximately 7.5 times than that (1.96) of the sensor made of pure NiO toward 100 ppm ethanol at 200 °C. Simultaneously, the sensors own excellent selectivity, lower detecting limitation (0.1 ppm ethanol) and notable moisture resistance, which demonstrate the excellent practicability of them in the field of Internet of Things (IoT). [ABSTRACT FROM AUTHOR]

Abstract The knowledge of how Aspergillus niger responds to ethanol can lead to the design of strains with enhanced ethanol tolerance to be utilized in numerous industrial bioprocesses. However, the current understanding about the response mechanisms of A. niger toward ethanol stress remains quite limited. Here, we first applied a cell growth assay to test the ethanol tolerance of A. niger strain ES4, which was isolated from the wall near a chimney of an ethanol tank of a petroleum company, and found that it was capable of growing in 5% (v/v) ethanol to 30% of the ethanol‐free control level. Subsequently, the metabolic responses of this strain toward ethanol were investigated using untargeted metabolomics, which revealed the elevated levels of triacylglycerol (TAG) in the extracellular components, and of diacylglycerol, TAG, and hydroxy‐TAG in the intracellular components. Lastly, stable isotope labeling mass spectrometry with ethanol‐d6 showed altered isotopic patterns of molecular ions of lipids in the ethanol‐d6 samples, compared with the nonlabeled ethanol controls, suggesting the ability of A. niger ES4 to utilize ethanol as a carbon source. Together, the studies revealed the upregulation of glycerolipid metabolism and ethanol utilization pathway as novel response mechanisms of A. niger ES4 toward ethanol stress, thereby underlining the utility of untargeted metabolomics and the overall approaches as tools for elucidating new biological insights.

Arthrobacter simplex has received considerable interests due to its superior Δ1-dehydrogenation ability. Ethanol used as co-solvent is a stress commonly encountered during biotransformation. Therefore, studies of ethanol tolerance of A. simplex are of great importance to improve the biotransformation efficiency. In this paper, the combined analysis of physiological properties, cell compositions, stress-responsive metabolites, and proteome profiles was carried out to achieve a global view of ethanol tolerance of A. simplex. Under sublethal conditions, cell permeability and membrane fluidity exhibited concentration-dependent increase by affecting the contents or compositions of cell peptidoglycan, lipids, phospholipids, and fatty acids. Among them, cis-trans isomerization of unsaturated fatty acids was a short-term and reversible process, while the changes in phospholipid headgroups and increase in saturation degree of fatty acids were long-term and irreversible processes, which collectively counteracted the elevated membrane fluidity caused by ethanol and maintained the membrane stability. The decreased intracellular ATP content was observed at high ethanol concentration since proton motive force responsible for driving ATP synthesis was dissipated. The involvement of trehalose and glycerol, oxidative response, and DNA damage were implicated due to their changes in positive proportion to ethanol concentration. Proteomic data supported that ethanol invoked a global alteration, among which, the change patterns of proteins participated in the biosynthesis of cell wall and membrane, energy metabolism, compatible solute metabolism, and general stress response were consistent with observations from cell compositions and stress-responsive metabolites. The protective role of proteins participated in DNA repair and antioxidant system under ethanol stress was validated by overexpression of the related genes. This is the first demonstration on ethanol tolerance mechanism of A. simplex, and the current studies also provide targets to engineer ethanol tolerance of A. simplex. [ABSTRACT FROM AUTHOR]