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Previous studies of the dynamics of sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB) have focused on deep stratified lakes. The objective of this study is to present an in-depth investigation of the structure and dynamics of sulfur bacteria (including SRB and SOB) in the water column of shallow freshwater lakes. A cyanobacterial bloom biomass (CBB)-amended mesocosm experiment was conducted in this study, in which water was taken from a shallow eutrophic lake with sulfate levels near 40 mg L−1. Illumina sequencing was used to investigate SRB and SOB species involved in CBB decomposition and the effects of the increases in sulfate input on the water column microbial community structure. The accumulation of dissolved sulfide (∑H2S) produced by SRB during CBB decomposition stimulated the growth of SOB, and ∑H2S was then oxidized back to sulfate by SOB in the water column. Chlorobaculum sequences (the main SOB species in the study) were significantly influenced by increases in sulfate input, with relative abundance increasing approximately four-fold in treatments amended with 40 mg L−1 sulfate (referred to as 40S) when compared to the treatment without additional sulfate addition (referred to as CU). Additionally, an increase in SOB number was observed from day 26–37, concurrent with the decrease in SRB number, indicating the succession of sulfur bacteria. These findings suggest that biological sulfur oxidation and succession of sulfur bacteria occur in the water column during CBB decomposition in shallow freshwater ecosystems, and the increases in sulfate input stimulate microbial sulfur oxidation.

Liquid chromatography with quadrupole time-of-flight mass spectrometry coupled with automated data analysis by Peakview software was employed to systematically screen and characterize the astragalosides in Radix Astragali, a Chinese medical preparation. The separation was performed on a poroshell 120 SB-C18 column equipped in a conventional liquid chromatography system. After being separated using a general gradient elution, the analytes were detected by the triple quadrupole time-of-flight mass spectrometer in both positive- and negative-ion modes. The mass defect filtering function built in the Peakview software was utilized to rapidly screen the potential ions of interest, while some functions of Peakview such as Formula Finder, XIC manager, and IDA Explorer were employed to facilitate the assignment or characterization of the screened astragalosides. A total of 42 astragalosides were screened and tentatively characterized or assigned, and 20 of them were firstly detected in Radix Astragali. According to the screened astragalosides, acetylation, glycosidation, hydrogenation, oxidation, and hydration were considered to be the major secondary metabolic pathways involved in the formation of the astragalosides. The combination of liquid chromatography with quadrupole time-of-flight mass spectrometry and automated Peakview analysis is a feasible and efficient tool to screen and identify the constituents in complex matrices of herbal medicines.

The side effects of cisplatin (CDDP), notably nephrotoxicity, greatly limited its use in clinical chemotherapy. HuangQi Injections (HI), a commonly used preparation of the well-known Chinese herbal medicine Astragali radix, appeared to be promising treatment for nephrotoxicity without compromising the anti-tumor activity of CDDP. In this study, the urinary metabolomics approach using liquid chromatography time of flight mass spectrometry (LC-TOF/MS) was developed to assess the toxicity-attenuation effects and corresponding mechanisms of HI on CDDP-exposed rats. As a result, successive administration of HI significantly recovered the decline of body weight and downregulated the abnormal increase of serum creatinine and urea. HI partly restored the CDDP-induced alteration of metabolic profiling back into normal condition. Totally 43 toxicity-attenuation potential biomarkers were screened and tentatively identified, which were involved in important metabolic pathways such as amino acid metabolism, TCA cycle, fatty acid metabolism, vitamin B6 metabolism and purine metabolism. The results clearly revealed that HI could alleviate CDDP-induced nephrotoxicity and improve the disturbed metabolic balance induced by repeated CDDP exposure. The present study provided reliable evidence for the protective effect of HI on CDDP-induced toxicity with the multi-target pharmacological characteristics.

The samples of Huangqi injection (HI) were analyzed by liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-TOF-MS), and both positive and negative ion modes were employed to obtain the LC-TOF-MS analysis information of chemical compounds in HI. Then the mass defect filtering (MDF) approach, which was developed based on the previously published articles, was utilized to rapidly screen the astragalosides from the obtained LC-TOF-MS data. Each screened astragaloside was confirmed by the presence of no less than 2 quasi-molecular ions. All the screened astragalosides were then tentatively assigned according to the parent ion and daughter ion information. Finally, a total of 62 astragalosides were screened and characterized from the HI samples, including 15 new detected ones. The identification results indicated that acetylation, hydrogenation, dehydrogenation, methoxylation and hydration might be the major conversion reactions involved in the formation of the astragalosides. The LC-TOF-MS-based MDF approach was proved to be a feasible and efficient tool to screen the chemical constituents in complex matrices such as herbal medicines.

Two new macrocyclic dinuclear copper(II) complexes, [Cu2L1(MeOH)2]·(ClO4)2 (1) and [Cu2L2(EtOH)2]·(ClO4)2 (2) have been synthesized and characterized by ES-MS spectra and X-ray crystallography determination. The coordination polyhedron of Cu(II) ions in each complex can be described as approximately square pyramind, where the apical position is occupied by a labile coordinated alcoholic molecule. The reactions of complexes with nitric oxide (NO) cause an immediate color change, and the formation of NO complexes has been further confirmed by UV/Vis spectrophotometry. The binding constants are calculated to be 1.71 × 103 M− 1 and 2.0 × 103 M− 1 in 0.2 M anaerobic phosphate buffer solution (PBS), respectively. The control experiments reveal that the binding of NO to complexes is reversible. Moreover, the interactions of the complexes with calf thymus DNA (CT-DNA) have been measured by UV/Vis, cyclic voltammetry and viscosity study. The moderate binding ability and unobvious DNA cleavage ability account for their low toxicity towards DNA. Overall, the results reveal that these two complexes can be served as potential NO regulators.

A new macrocyclic dinuclear Zn(II) complex, [Zn2(OAc)L] · ClO4 (H2L was obtained by condensation between 3,3′-(ethane-1,2-diylbis(benzylazanediyl))bis(methylene)bis(2-hydroxy-5-methylbenzaldehyde) and aniline (1 : 2 molar ratio)), was synthesized and characterized by spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The interactions of the complex with DNA have been measured by UV spectroscopy and viscosity experiment. The interaction of the complex with calf thymus DNA has a binding constant of 1.18 × 104 mol−1 L. Phosphate hydrolysis of the complex was investigated using bis(4-nitrophenyl)phosphate as the substrate. The observed first-order rate constant is 4.23 × 10−5 s−1.

Liquid chromatography with quadrupole time-of-flight mass spectrometry coupled with automated data analysis by Peakview software was employed to systematically screen and characterize the astragalosides in Radix Astragali, a Chinese medical preparation. The separation was performed on a poroshell 120 SB-C18 column equipped in a conventional liquid chromatography system. After being separated using a general gradient elution, the analytes were detected by the triple quadrupole time-of-flight mass spectrometer in both positive- and negative-ion modes. The mass defect filtering function built in the Peakview software was utilized to rapidly screen the potential ions of interest, while some functions of Peakview such as Formula Finder, XIC manager, and IDA Explorer were employed to facilitate the assignment or characterization of the screened astragalosides. A total of 42 astragalosides were screened and tentatively characterized or assigned, and 20 of them were firstly detected in Radix Astragali. According to the screened astragalosides, acetylation, glycosidation, hydrogenation, oxidation, and hydration were considered to be the major secondary metabolic pathways involved in the formation of the astragalosides. The combination of liquid chromatography with quadrupole time-of-flight mass spectrometry and automated Peakview analysis is a feasible and efficient tool to screen and identify the constituents in complex matrices of herbal medicines.

The lipase genes of Yarrowia lipolytica, LIPY7 and LIPY8, fused with FLO-flocculation domain sequence from Saccharomyces cerevisiae at their N-termini, were expressed in Pichia pastoris KM71. Following the induction with methanol, the recombinant proteins were displayed on the cell surface of P. pastoris, as confirmed by the confocal laser scanning microscopy. The LipY7p and LipY8p were anchored on P. pastoris via the flocculation functional domain of Flo 1 p. The surface-displayed lipases were characterized for their application as the whole-cell biocatalyst. These lipases can also be cleaved off from their anchor by enterokinase treatment to yield functionally active proteins in the supernatant offering an alternative purification method for LipY7p and LipY8p. (c) 2007 Elsevier Inc. All rights reserved.

A novel surface-display system was constructed using the cell-wall anchor protein Flo I p from Saccharomyces cerevisiae, the mannanase (man I from Bacillus subtilis fused with the C-terminus of Flo I p and the 6 x His tag was inserted between Flo l p and man I. The fusion protein was displayed on the cell surface of Yarrowia lipolytica successfully, and it was confirmed by immunofluorescence. In succession, the surface-displayed mannanase was characterized. The optimum catalytic conditions for the recombinant mannanase were 55 °C at pH 6.0, and it exhibited high stability against pH variation. The highest activity of the recombinant mannanase reached 62.3 IU/g (dry cell weight) after the recombinant was cultivated for 96 h in YPD medium [I % (w/v) yeast extract/2 % (w/v) peptone/2 % (w/v) glucose]. To our knowledge, the present paper is the first to report that high-activity mannanase is displayed on the cell surface of Y. lipolytica with Flo I p.

We isolated two lipase genes LIPY7, LIPY8 from Yarrowia lipolytica CGMCC (China general microbiological culture collection center) AS 2.1216. The LIPY7 and LIPY8 genes encode a 366 and a 371-amino acid protein, respectively. The lipase genes with 6 x His tag sequence were cloned into expression vector pPIC9K and successfully integrated into a heterologous fungal host Pichia pastoris KM71, respectively. The recombinants were induced by methanol to secrete active lipases into cultural medium. The recombinant lipases were also purified and characterized.

The endo-1,4-xylanase gene from Bacillus pumilus HB030 was cloned into the Pichia pastoris expression vector, pPIC9k, the recombinant plasmid was named pHBM220. The digested recombinant plasmid pHBM220 was transformed into Pichia pastoris KM71, GS115, SMD1168, respectively. The recombinant Pichia pastoris KM71 (pHBM220), GS115 (pHBM220), SMD1168 (pHBM220) secreted functional endo-1,4-xylanase, and the enzymatic activities reached 10.80IU/mL, 11.63IU/mL, 9.68IU/mL, respectively. The temperature and pH optimum for the recombinant xylanase were 60 degrees C and pH5.5, respectively.

In the title solvated mol-ecular salt, [CuCl(C(28)H(30)N(4))]ClO(4)·CH(3)OH, the Cu(2+) ion is coordinated by the N,N',N'',N'''-tetra-dentate ligand and a chloride ion, generating a very distorted square-based pyramidal CuN(4)Cl coordination geometry with the Cl(-) ion in the basal position. In the crystal, the solvent mol-ecules and anions are linked by weak O-H⋯O hydrogen bonding.

In the unsymmetrical title complex, [Ni(C20H23N4O4)]ClO4, the coordination geometry for the NiII atom can be described as square planar. The aromatic rings in the two ligands are almost vertical, with a dihedral angle of 85.3°. In the crystal, cations and anions are linked by weak C(N)—H...O hydrogen bonding.