Currently, Euro 5 (no more than 10 ppm sulfur content) and Euro 6 (less than 10 ppm sulfur content) diesel motor fuels are produced worldwide. High-quality diesel fuels are produced by removing sulfur compounds using a hydrodesulfurization process. This article is devoted to the study of hydrodesulfurization of diesel fuel containing 120 ppm of sulfur compounds in the presence of an Al-Ni-Mo-O catalyst with a 98% diesel fuel purification rate. According to the Langmuir–Hinshelwood–Panchenkov theory, a kinetic model of the process is developed with the calculation of the theoretical change in the entropy and enthalpy of the activation of the hydrodesulfurization process. The mathematical model, for the first time, takes into account the influence of the pressure of substances involved in the process on the transformation of sulfur-containing compounds. A mechanism for diesel fuel hydrotreating from sulfur-containing compounds is formulated using a generalized quantum-chemical principle. The hydrodesulfurization mechanism includes nine stages. The formulated mechanism and developed mathematical model of hydrotreating fully describe the reaction of the hydrodesulfurization of diesel fuel and show the possibility of regulating and controlling this industrially important process.
The phenomenon of cytoplasmic male sterility (CMS), consisting in the inability to produce functional pollen due to mutations in mitochondrial genome, has been described in more than 150 plant species. With the discovery of nuclear fertility restorer (Rf) genes capable of suppressing the CMS phenotype, it became possible to use the CMS-Rf genetic systems as the basis for practical utilization of heterosis effect in various crops. Seed production of sunflower hybrids all over the world is based on the extensive use of the PET1 CMS combined with the Rf1 gene. At the same time, data on Rf1 localization, sequence, and molecular basis for the CMS PET1 type restoration of fertility remain unknown. Searching for candidate genes of the Rf1 gene has great fundamental and practical value. Therefore, in this study, association mapping of fertility restorer gene for CMS PET1 in sunflower was performed. The genome-wide association study (GWAS) results made it possible to isolate a segment 7.72 Mb in length on chromosome 13, in which 21 candidates for Rf1 fertility restorer gene were identified, including 20 pentatricopeptide repeat (PPR)family genes and one Probable aldehyde dehydrogenase gene. The results will serve as a basis for further study of the genetic nature and molecular mechanisms of pollen fertility restoration in sunflower, as well as for further intensification of sunflower breeding.
A novel anaerobic, endospore-forming bacterium (strain M08 DMBT) was isolated from a terrestrial mud volcano (Taman Peninsula, Russia). Cells of the strain were motile rods 1.3–2.0 µm long and 0.4 µm in diameter. The temperature range for growth was 5–42 °C, with an optimum at 30 °C. The pH range for growth was H 6.5–11.0, with an optimum at pH 8.0. Growth of strain M08 DMBTwas observed at NaCl concentrations of 0–5.0 % (w/v) with an optimum at 1.0 %. Strain M08 DMBTutilized 3,4-dimethoxybenzoic acid, 2-methoxyphenol, carbon monoxide, glucose, fructose, mannose, xylose and yeast extract. The end product of glucose fermentation was acetate. The DNA G+C content of strain M08 DMBTwas 32.3 mol% (obtained via whole genome sequencing). The closest phylogenetic relative of strain M08 DMBTwasAlkalibaculum bacchi(familyEubacteriaceae, classClostridia) with 95.17 % 16S rRNA gene sequence similarity. Based on the phenotypic, genotypic and phylogenetic characteristics of the isolate, strain M08 DMBTis considered to represent a novel species of the genusAlkalibaculum, for which the nameAlkalibaculum sporogenessp. nov. is proposed. The type strain ofAlkalibaculum sporogenesis M08 DMBT(=KCTC 15840T=VKM B-3387T).
1 February 2018 in Journal of Alloys and Compounds