Microbacterium kunmingensis sp. nov., an attached bacterium of Microcystis aeruginosa.

A Gram-stain positive, aerobic, rod-shaped actinobacterial strain designated as JXJ CY 27-2T was isolated from the culture of Microcystis aeruginosa FACHB-905 (Maf) collected from Lake Kunming, southwest China. The isolate was catalase positive, oxidase negative, and able to grow at 10.0-44.0 °C, pH 5.0-10.0 and 0-5.0% NaCl. Based on the 16S rRNA gene sequences, JXJ CY 27-2T showed high similarities of 98.54-98.55% with Microbacterium invictum DSM 19600T, Microbacterium saccharophilum DSM 28107T, and Microbacterium aoyamense DSM 19461T, and less than 98.47% similarities with other members of the genus. Its major cellular fatty acids were anteiso-C17:0 and anteiso-C15:0. The predominant menaquinones were MK-11 and MK-12. The diagnostic diamino acid in the cell wall peptidoglycan was lysine. Whole cell sugars contained mannose, ribose, galactose, rhamnose and arabinose. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, two unidentified glycolipids, and an unidentified lipid. The DNA G + C content was 69.8%. The digital DNA-DNA hybridization and average nucleotide identity values between strain JXJ CY 27-2T and its three closest similar strains were 18.4-20.3% and 74.9-75.7%, respectively. Based on the above data, strain JXJ CY 27-2T was identified as a new species of the genus Microbacterium, for which the name Microbacterium kunmingensis sp. nov. is proposed. The type strain is JXJ CY 27-2T (=CGMCC 1.17506T = KCTC 49382T). Strain JXJ CY 27-2T could promote the growth of Maf by providing it with available phosphorus, nitrogen and probably other nutrients such as vitamins and indole-3-acetate.

Structural, Spectroscopic, and Theoretical Investigation of a T-Shaped [Fe3(µ3-O)] Cluster.

The synthesis, X-ray crystal and electronic structures of [Fe3(µ3-O)(mpmae)2(OAc)2 Cl3], 1, where mpmae-H = 2-(N-methyl-N-((pyridine-2-yl)methyl)amino)ethanol, are described. This cluster comprises three high-spin ferric ions and exhibits a T-shaped site topology. Variable-frequency electron paramagnetic resonance measurements performed on single crystals of 1 demonstrate a total spin ST = 5/2 ground state, characterized by a small, negative, and nearly axial zero-field splitting tensor D = -0.49 cm-1, E/D ≈ 0.055. Analysis of magnetic susceptibility, magnetization, and magneto-structural correlations further corroborate the presence of a sextet ground-spin state. The observed ground state originates from the strong anti-ferromagnetic interaction of two iron(III) spins, with J = 115(5) cm-1, that, in turn, are only weakly coupled to the spin of the third site, with j = 7(1) cm-1. These exchange interactions lead to a ground state with magnetic properties that are essentially entirely determined by the weakly coupled site. The contributions of the individual spins to the total ground state of the cluster were monitored using variable-field 57Fe Mössbauer spectroscopy. Field-dependent spectra reveal that, while one of the iron sites exhibits a large negative internal field, typical of ferric ions, the other two sites exhibit small, but not null, negative and positive internal fields. A theoretical analysis reveals that these small internal fields originate from the mixing of the lowest ST = 5/2 excited state into the ground state which, in turn, is induced by a minute structural distortion.

[Photoinduced intra-molecular energy transfer of a novel phthalocyanine zinc(II) bearing poly (aryl benzyl ether) dendritic substitutents with carboxylic terminal].

The photoinduced intra-molecular energy transfer in phthalocyanine zinc(II) bearing poly (aryl benzyl ether) dendritic substituents with carboxylic terminal was studied by steady-state, time-resolved fluorescence and UV/Vis spectroscopic methods. The result shows that the complexes mainly existed as monomers in dimethyl sulfoxide. The light-harvesting ability of this series of dendritic phthalocyanines increased with the dendron generation under 270 nm. The effects of the dendron generation on the fluorescence characteristics of phthalocyanine cores was significantly, and the fluorescence lifetime and fluorescent quantum yield decreased with the increase of the dendron generation. Intra-molecular energy could be transferred from peripheral dendron acting as an energy hydrazine to the phthalocyanine core during a photo-induced process. With the dendrimer increasing, the intra-molecular energy transfer quantum yield increased. These results obviously indicated that this series of dendritic phthalocyanines is a king of novel compound with light-harvesting structure.

Experimental study on the photodynamic treatment of choroidal neovasculization with nanophthalocyanine photosensitizer.

AIM: To investigate the therapeutic effects of nanophthalocyanine photosensitizers on an experimental rat choroidal neovescularization (CNV) model, as well as to evaluate the cytotoxicity of which on human retinal pigment epithelia (HRPE) and human retinal endothelial cells (HRECs). METHODS: Two types of photosensitizers, G(1)-ZnPc(COOH)(8) and G(1)-ZnPc(COOH)(8)/m respectively, were administrated for photodynamic therapy (PDT) after a successful establishment of CNV model on Brown-Norway (BN) rats via fundus photocoagulation. The therapeutic effects of the two drugs were assessed through optical coherence tomography (OCT), fluorescein fundus angiography (FFA) and transmission electron microscopy (TEM). For cytotoxicity tests, cell counting kit-8 (CCK-8) assays and changes of mitochondrial transmembrane potential (△Ψm) were conducted on HRPE and HRECs after initial uptake of the two drugs. RESULTS: Both photosensitizers demonstrated an improvement of vascular leakage and closure of CNV 1 week after PDT as confirmed by fundus image, OCT, FFA and TEM. Two weeks after PDT, G(1)-ZnPc(COOH)(8)/m showed a better CNV closure effect versus G(1)-ZnPc(COOH)(8) (P<0.05). A significant difference (P<0.01) was found in uptake of the two drugs in HRPE and HRECs, with no difference between the drugs (P>0.05). Both photosensitizers showed cytotoxicity on HRPE, but G(1)-ZnPc(COOH)(8)/m induced a lower cell viability. CONCLUSION: G(1)-ZnPc(COOH)(8)/m mediated PDT is better than G(1)-ZnPc(COOH)(8) in CNV closure and also have the advantage of fast metabolism leading to less side effect.

[Study on the interaction of tetra-sulfonated phathalocyanine cobalt with bovine serum albumin].

The tetra-sulfonated phathalocyanine cobalt(CoPcS4)was synthesized by using 4-sulfonic phthalic acid as raw material, CoCl2 as template agent and (NH4)2 MoO4 as catalyst. CoPcS4 was demonstrated to be C4h mono-isomer by elementary analysis, IR, NMR and HLPC. Depolymerization of CoPcS4 was found in DMSO. The depolymerization increased with the pH value raising. The interaction of tetra-sulfonated phathalocyanine cobalt with bovine serum albumin (BSA) was studied by UV-Vis and fluorescence spectra The number of binding sites and binding constant were determined at equal pace of the order of magnitude 10(5) L x mol(-1). CoPcS4 binds with BSA at Site I and Site II. In conclusion, COPcS4 binds with BSA commendably and albumin plays a role of storage and transport.

[Synthesis and characterization of octa-carboxylic phthalocyanine aluminum and its interaction with bovine serum albumin].

Octa-carboxylic phthalocyanine aluminium (AlPc(COOH)8) was used as fluorescent probe of infrared region. The interaction of octa-carboxylic phthalocyanine aluminium (AlPc(COOH)s) and bovine serum albumin(BSA) was studied by UV/ Vis and fluorescence spectra methods. The binding constant KA and n of phthalocyanine aluminium with BSA were determined. The results were K=5. 74 X 10(5) , n= 5. 7 and K= 3. 51 X 10(5) , for these two methods respectively. The same results by using two different analytical methods were obtained. Besides, hemin chloride(HE), ibuprofen(IB) and L-tryptophan(TRP) were used as probes, and the effects of these probes on the spectra of AlPc(COOH)8 )-BSA were studied by competitive binding method. The result indicated that, by adding HE into the AlPc(COOH)8)-BSA system, obvious spectral change of the system was observed, while adding TRP and IB caused no spectral changes. The binding site of octa-carboxylic phthalocyanine aluminium on the BSA was found to be at the I site by competitive binding method.

[Study on surface-capped CdS nanoparticles as fluorescence probes].

In the present paper, CdS nanoparticles of different size surface-capped with thiourea [expressed as CdS/SC(NH2)2] were prepared by sol-gel method, and characterized by XRD, TEM, IR and PL. The results show that the molar ratio of thiourea to cadmium ion has influence on the size and luminescence properties of the nanoparticles. With increasing the mdar ratio of thiourea to cadmium ion in the reactant, the size of the nanoparticles decreases, and the maximum emission wavelength of the nanoparticles shows an obvious blue shift due to quantum confinement effect. The effect of calf thymus deoxyribonucleic acid (ct-DNA) on the fluorescence spectrum of the CdS/SC(NH2)2 nanoparticles was also studied. The result shows that the intensity of fluorescence spectrum of the nanoparticles is quenched by ct-DNA, which is probably caused by the electrostatic interaction between CdS/SC(NH2)2 nanoparticles and ct-DNA. The CdS/SC(NH2)2 nanoparticles are hopeful of being used as fluorescence probes in DNA determination.