摘要：
The halophilic archaea (haloarchaea) live in hyersaline environments such as salt lakes, salt ponds and marine salterns. To cope with the salt stress conditions, haloarchaea have developed two fundamentally different strategies: the "salt-in" strategy and the "compatible-solute" strategy. Although investigation of the molecular mechanisms underlying the tolerance to high salt concentrations has made outstanding achievements, experimental study from the aspect of transcription is rare. In the present study, we monitored cellular physiology of Natrinema sp. J7-2 cells incubated in different salinity media (15%, 25% and 30% NaCl) from several aspects, such as cellular morphology, growth, global transcriptome and the content of intracellular free amino acids. The results showed that the cells were polymorphic and fragile at a low salt concentration (15% NaCl) but had a long, slender rod shape at high salt concentrations (25% and 30% NaCl). The cells grew best in 25% NaCl, mediocre in 30% NaCl and struggled in 15% NaCl. An RNA-seq analysis revealed differentially expressed genes (DEGs) in various salinity media. A total of 1,148 genes were differentially expressed, consisting of 719 DEGs (348 up-regulated and 371 down-regulated genes) between cells in 15% vs 25% NaCl, and 733 DEGs (521 up-regulated and 212 down-regulated genes) between cells in 25% vs 30% NaCl. Moreover, 304 genes were commonly differentially expressed in both 15% vs 25% and 25% vs30% NaCl. The DEGs were enriched in different KEGG metabolic pathways, such as amino acids, glycerolipid, ribosome, nitrogen, protoporphyrin, porphyrin and porhiniods. The intracellular predominant free amino acids consisted of the glutamate family (Glu, Arg and Pro), aspartate family (Asp) and aromatic amino acids (Phe and Trp), especially Glu and Asp.
摘要：
A new Schiff base 2-[3-chloropyridin-2-yl) hydrazonemethyl]-6-ethoxyphenol (HL) and its new iron(III) complex have been synthesized and characterized by elemental analysis, IR spectra, and single-crystal X-ray determination. The Schiff base was crystallized in the triclinic space group P (1) over bar, and the complex was crystallized in the monoclinic space group Cc. The particular interest is to study the coordination behavior of the Schiff base with iron. Single-crystal X-ray diffraction indicated that the Schiff base ligand coordinates to the Fe atom through the phenolate O, imine N, and pyridine N atoms. The asymmetric unit of the Schiff base contains two Schiff base molecules and one methanol molecule. The asymmetric unit of the complex contains two mononuclear iron(III) complex cations and two trifluoromethylsulfate anions. The Fe atom is six-coordinated in an octahedral geometry. The coordination of the Schiff base to the Fe atom is also reflected in the IR spectra. Crystal structures of the compounds are stabilized by hydrogen bonds.
关键词：
Azido;Copper complex;Crystal structure;Hydrogen bond;Schiff base
摘要：
A mononuclear copper(II) complex, [(CuLN3)-N-1] (1), and a dinuclear copper(II) complex, [Cu-2(L-2)(2)(mu(1),(1)-N-3)(2)] (2), where L-1 and L-2 are the deprotonated forms of 2-[(2-diethylaminoethylimino) methyl]-4,6-difluorophenol (HL1) and 2,4-difluoro-6-[(2-isopropylaminoethylimino) methyl] phenol (HL2), respectively, were prepared. The complexes were characterized by elemental analysis, infrared (IR) and UV-Vis spectra, and single crystal X-ray determination. The crystal of complex 1 crystalizes in the orthorhombic space group Pbca, with unit cell a = 6.9327(7), b = 13.8926(13), c = 31.243(2) angstrom, V = 3009.1(5) angstrom(3) , Z = 8. The crystal of complex 2 crystalizes in the monoclinic space group P2(1)/n, with unit cell a = 20.8686(16), b = 9.4893(16), c = 7.2440(12) angstrom , beta = 94.020(2)degrees, V = 1431.0(4) angstrom(3) , Z = 4. The Cu atom in complex 1 is in square planar geometry, and that in complex 2 is in square pyramidal geometry.
摘要：
Although viruses of haloarchaea are the predominant predator in hypersaline ecosystem, the culture studies about halovirus-host systems are infancy. The main reason is the tradition methodology (plaque assay) for virus-host interaction depends on culturable and susceptible host. Actually, more than 90% of haloarchaea are unculturable. Therefore, it is necessary to establish an approach for detecting the dynamics of virus in hypersaline environment without culture. In this study, we report a convenient method to determine the dynamics of halovirus SNJ1 based on quantitative real-time PCR (qPCR). All findings showed that the qPCR method was specific (single peak in melt curves), accurate (a good linear relationship between the log of the PFU and the C-t values, R-2 = 0.99), reproducible (low coefficient of variations, below 1%). Additionally, the physicochemical characteristics of the samples tested did not influence the stability of qPCR. Therefore, the qPCR method has the potential value in quantifying and surveying haloviruses in halophilic ecological system.
