Comparative Characterization and Identification of Poly-3-Hydroxybutyrate Producing Bacteria with Subsequent Optimization of Polymer Yield

In this work, the strains Bacillus megaterium BM 1, Azotobacter chrocococcumAz 3, Bacillus araybhattay RA 5 were used as an effective producer of poly-3-hydroxybutyrate P(3HB). The purpose of the study was to isolate and obtain an effective producer of P(3HB) isolated from regional chestnut soils of northern Kazakhstan. This study demonstrates the possibility of combining the protective system of cells to physical stress as a way to optimize the synthesis of PHA by strains. Molecular identification of strains and amplification of the phbC gene, transmission electron microscope (TEM), extracted and dried PHB were subjected to Fourier infrared transmission spectroscopy (FTIR). The melting point of the isolated P(3HB) was determined. The optimal concentration of bean broth for the synthesis of P(3HB) for the modified type of Bacillus megaterium RAZ 3 was 20 g/L, at which the dry weight of cells was 25.7 g/L−1 and P(3HB) yield of 13.83 g/L−1, while the percentage yield of P(3HB) was 53.75%. The FTIR spectra of the extracted polymer showed noticeable peaks at long wavelengths. Based on a proof of concept, this study demonstrates encouraging results.

The Infrared Complex Refractive Index of Amorphous Ammonia Ice at 40 K (1.43–22.73 μm) and Its Relevance to Outer Solar System Bodies

A near-IR absorption band at 2.2 μm linked to ammonia-containing ice has been detected on icy bodies throughout the solar system and appears in the extensive volume of data for Pluto and Charon returned by New Horizons. This band is an important clue for understanding the abundance of ammonia and ammoniated compounds on the surface of outer solar system bodies and requires new laboratory data for its full analysis. To satisfy this data need, the complex refractive index of amorphous ammonia ice was calculated from experimental infrared transmission spectra with ice deposition and measurements conducted at 40 K, a characteristic surface temperature for outer solar system bodies. The measured imaginary part of the complex refractive index and associated band strength calculations are generally larger than prior published values for amorphous ammonia ice at 30 K. The complex refractive index for amorphous ammonia at 40 K computed in the mid-infrared region (2.5–22.73 μm) will also be valuable for interpreting observations of both solar system and astrophysical sources anticipated with the Near InfraRed Spectrograph and Mid-Infrared Instrument on the James Webb Space Telescope.

Diagnostics of atomic- molecular interactions in nano-compositions organics-inorganics by means of infrared spectroscopy

This paper prolongs our studies of the formation and properties of the organic-inorganic scintillating compositions from activated polystyrene and inorganic nanoparticles from cesium iodid and sulfate. The compositions from the solution of polystyrene in benzene and nano- or micro-particles of cesium iodide were solidified in the form of thin films. Then some of the films were subjected to rolling. The variations of the infrared transmission spectra of the compositions were measured either during their solidification or after the solidification and rolling. The new absorption band was revealed in the process of the solidification and disappeared after it. The fractal-like structures of parallel rows were formed in the films. Quasi-periodical oscillations of the transmission spectra were found in several infrared regions ascribed to the interaction of the infrared radiation with the fractal super-structure of the films. The modifications of the absorption spectra found in our experiments are attributed to the interactions of polystyrene molecules with benzene molecules and nanoparticles of cesium iodide.

Diamond-Coated Silicon ATR Elements for Process Analytics

Infrared attenuated total reflection (ATR) spectroscopy is a common laboratory technique for the analysis of highly absorbing liquids or solid samples. However, ATR spectroscopy is rarely found in industrial processes, where inline measurement, continuous operation, and minimal maintenance are important issues. Most materials for mid-infrared (MIR) spectroscopy and specifically for ATR elements do not have either high enough infrared transmission or sufficient mechanical and chemical stability to be exposed to process fluids, abrasive components, and aggressive cleaning agents. Sapphire is the usual choice for infrared wavelengths below 5 µm, and beyond that, only diamond is an established material. The use of diamond coatings on other ATR materials such as silicon will increase the stability of the sensor and will enable the use of larger ATR elements with increased sensitivity at lower cost for wavelengths above 5 µm. Theoretical and experimental investigations of the dependence of ATR absorbances on the incidence angle and thickness of nanocrystalline diamond (NCD) coatings on silicon were performed. By optimizing the coating thickness, a substantial amplification of the ATR absorbance can be achieved compared to an uncoated silicon element. Using a compact FTIR instrument, ATR spectra of water, acetonitrile, and propylene carbonate were measured with planar ATR elements made of coated and uncoated silicon. Compared to sapphire, the long wavelength extreme of the spectral range is extended to approximately 8 μm. With effectively nine ATR reflections, the sensitivity is expected to exceed the performance of typical diamond tip probes.