Relationship between Neutrophins and Gut Microbiome in Various Metabolic Types of Obesity

Journal of Evolutionary Biochemistry and Physiology - Obesity is associated with a gut microbiome imbalance and the risk of neurological complications. However, the risk of complications is...     

Ricochet inter-ring haptotropic rearrangement of σ-methyl-(η-indenyl) chromium tricarbonyls. Experimental kinetic and theoretical DFT study

σ-Methyl-(η⁵-indenyl) chromium tricarbonyl (III) rearranges quantitatively into η⁶-1-endo-methylindene) chromium tricarbonyl (IV) in C₆D₆ solution at 30–60°C. Methyl group attachment to the positions 2 or 3 of indenyl ligand in (III) has no influence on the activation parameters of this ricochet inter-ring haptotropic rearrangement (ΔG^#=23.6 kcal mol⁻¹; ΔH^#=18.9±0.2 kcal mol⁻¹; ΔS^#=−18.6±0.2 cal K⁻¹ mol⁻¹). (IV) undergoes further irreversible isomerization at 60–120° into (ν⁶-3-methylindene) chromium tricarbonyl (V) with a higher activation barrier (ΔG^#=28.5±0.1 kcal mol⁻¹) via two consecutive [1,5]-sigmatropic hydrogen shifts. The mechanisms of both rearrangements have been studied in detail using density functional theory (DFT) calculations with extended basis sets. Calculations show that the rearrangement (III) → (IV) proceeds in two steps. Methyl group migration from chromium into position 1 of the indenyl ligand is the rate-determining step leading to the formation of the 16-electron intermediate (VII). The calculated activation barrier (E_a=19.6 kcal mol⁻¹) is in good agreement with the experimental one. Further rearrangement (VII) → (V) proceeds via a trimethylenemethane-type transition state (XVIII) with an activation barrier 11.8 kcal mol⁻¹. The coordination of the chromium tricarbonyl group at the six-membered ring has only minor influence on the kinetic parameters of the hydrogen [1,5]-sigmatropic shift in indene.     

Composition of the oil-slime microbial community as determined by analysis of the 16S rRNA gene

Analysis of the 16S rRNA genes of the cultured microorganisms of industrial oil-slime revealed predominance (～85–90%) of the Gammaproteobacteria in the community of aerobic heterotrophs and specific oil-slime degraders. Relation of the isolated strains with members of the genera Pseudomonas, Stenotrophomonas, and Enterobacter was established. Analysis of the same gene in the total DNA from the oil-slime revealed greater microbial diversity (～20 operative taxonomic units determined by T-RFLP) than in the cultured part of the community, which included ～12 different colony types. Three major restriction fragments were found, with their total area ～50%. These results demonstrated the low morphological and phylogenetic diversity of the oil-slime bacterial community.     

Quantitative Analysis of Bacillus pumilus Serine Proteinases in Recombinant Bacillus Strains

Microbiology - A comparative study of the expression of B. pumilus extracellular serine proteinases (subtilisin-like proteinase and glutamyl endopeptidase) under the control of different promoters...