The removal of ρ-chlorophenol in aqueous cultures with free and alginate-immobilized cells of the microalga Tetraselmis suecica

The present study aimed at evaluating the ability of some isolated cyanobacterial and microalgal strains for the removal of ρ-chlorophenol (ρ-CP), an environmentally harmful contaminant. To identify the most efficient species, a screening program was carried out using 15 microalgal and cyanobacterial strains. Among them, Tetraselmis suecica was able to remove 67 % of the ρ-chlorophenol at an initial concentration of 20 mg L^?1 from the medium within a 10-day period. The efficacy of the process was dependent on the ρ-chlorophenol concentration. At concentrations above 60 mg L^?1 of the pollutant, no removal was observed due to the inhibitory effect of ρ-chlorophenol on the T. suecica cells. The effect of cell immobilization in alginate beads on T. suecica removal capacity was also examined. Using this technique, the removal efficacy for the initial ρ-CP concentration of 20 mg L^?1 increased up to 94 %.     

Insights into laccase producing organisms,fermentation states,purification strategies,and biotechnological applications

Laccases are phenol oxidases belonging to the superfamily of multicopper oxidases and are found in bacteria, fungi, lichens, higher plants, and insects. Over the past few decades, laccases and laccase mediator systems (LMS) have found uses in a wide range of technological applications such as textile dye decolorization, industrial wastewater detoxification, pulp bleaching, chemical synthesis, and development of miniaturized biosensors. This has encouraged numerous studies to find and purify laccases with exploitable characteristics. The main aim of the present review is to summarize the rich literature data gained in recent years from the studies on laccases, focusing on the organisms that produce them, the methods used for screening, laccase activity assays, purification strategies, and the application of laccases as eco‐friendly biocatalysts. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1443–1463, 2015     

Green synthesis of gold nanoparticles by the marine microalga Tetraselmis suecica

The application of green-synthesis principles is one of the most impressive research fields for the production of nanoparticles. Different kinds of biological systems have been used for this purpose. In the present study, AuNPs (gold nanoparticles) were prepared within a short time period using a fresh cell extract of the marine microalga Tetraselmis suecica as a reducing agent of HAuCl4 (chloroauric acid) solution. The UV-visible spectrum of the aqueous medium containing AuNPs indicated a peak at 530 nm, corresponding to the surface plasmon absorbance of AuNPs. The X-ray diffraction pattern also showed a Bragg reflection related to AuNPs. Fourier-transform infrared spectroscopy was performed for analysis of surface functional groups of AuNPs. Transmission electron microscopy and particle-size-distribution patterns determined by the laser-light-scattering method confirmed the formation of well-dispersed AuNPs. The most frequent size of particles was 79 nm.     

3‐Aryl Coumarin Derivatives Bearing Aminoalkoxy Moiety as Multi‐Target‐Directed Ligands against Alzheimer's Disease

Two series of novel coumarin derivatives, substituted at 3 and 7 positions with aminoalkoxy groups, are synthesized, characterized, and screened. The effect of amine substituents and the length of cross‐linker are investigated in acetyl‐ and butyrylcholinesterase (AChE and BuChE) inhibition. Target compounds show moderate to potent inhibitory activities against AChE and BuChE. 3‐(3,4‐Dichlorophenyl)‐7‐[4‐(diethylamino)butoxy]‐2H‐chromen‐2‐one ( 4y ) is identified as the most potent compound against AChE (IC₅₀=0.27 μm ). Kinetic and molecular modeling studies affirmed that compound 4y works in a mixed‐type way and interacts simultaneously with the catalytic active site (CAS) and peripheral anionic site (PAS) of AChE. In addition, compound 4y blocks β‐amyloid (Aβ) self‐aggregation with a ratio of 44.11 % at 100 μm and significantly protects PC12 cells from H₂O₂‐damage in a dose‐dependent manner.     

Lipopeptide Biosurfactant from Acinetobacter junii B6: A Promising Natural Surfactant for Promoting Angiogenesis

International Journal of Peptide Research and Therapeutics - Lipopeptide biosurfactants (LPBs) display unique properties with widespread therapeutic applications. Recently, the wound healing...     

Hybrid Pharmacophore Design,Molecular Docking,Synthesis, and Biological Evaluation of Novel Aldimine‐Type Schiff Base Derivatives as Tubulin Polymerization Inhibitor

A series of hybrid aldimine‐type Schiff base derivatives including trimethoxyphenyl ring and 1,2,4‐triazole‐3‐thiol/thione were designed as tubulin inhibitors. The molecular docking simulations on tubulin complex (PDB: 1SA0) revealed that derivatives with nitro and/or chloro or dimethylamino substitutes (4‐nitro, 2‐nitro, 3‐nitro, 4‐Cl‐3‐nitro, and 4‐Me₂N) on the aldehyde ring were the best compounds with remarkable binding energies (?9.09, ?9.07, ?8.63, ?8.11, and ?8.07 kcal mol^?1, respectively) compared to colchicine (?8.12 kcal mol^?1). These compounds were also showed remarkable binding energies from ?10.66 to ?9.79 and ?10.12 to ?8.95 kcal mol^?1 on human (PDB: 1PD8) and Candida albicans (PDB: 3QLS) DHFR, respectively. The obtained results of cytotoxic activities against HT1080, HepG2, HT29, MCF‐7, and A549 cancer cell lines indicated that 4‐nitro and 2‐nitro substituted compounds were the most effective agents by mean IC₅₀ values of 11.84 ± 1.01 and 19.92 ± 1.36 μm , respectively. 4‐Nitro substituted compound (5 μm ) and 2‐nitro substituted compound (30 μm ) were able to strongly inhibit the tubulin polymerization compared to colchicine (5 μm ) and 4‐nitro substituted compound displayed IC₅₀ values of 0.16 ± 0.01 μm compared to that of colchicine (0.19 ± 0.01 μm ). This compound also showed the lowest MIC values on all tested microbial strains including three Gram‐positive, four Gram‐negative, and three yeast pathogens.     

Delignification and detoxification of peanut shell bio-waste using an extremely halophilic laccase from an Aquisalibacillus elongatus isolate

Extremophiles - Lignocellulose bioconversion is a harsh process requiring the use of surfactants and organic solvents. Consequently, the incorporation of laccases in this bioconversion requires the...     

Purification and biochemical characterization of extracellular laccase from the ascomycete Paraconiothyrium variabile

An extracellular laccase-producing ascomycete was isolated from soil and identified as Paraconiothyrium variabile using rDNA sequence analysis. Typical laccase substrates including 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS), 2,6-dimethoxyphenol (DMP), and guaiacol were oxidized by the purified enzyme (designated as PvL). The molecular mass of PvL was 84 kDa and it showed a pI value of 4.2. The enzyme acted optimally at pH 4.8 and exhibited an optimum temperature of 50 °C. Using ABTS, PvL represented Km and Vmax of 203 μM and 40 μmol min(-1) mg(-1), respectively. After 24 h incubation at pH 4.8 and 4 °C, 80% of the initial activity of PvL remained. The enzyme was inhibited by Fe2+, Hg2+, and Mn2+, but induced by Cu2+. EDTA (10 mM), 1,4-dithiothreitol (DTT) (0.1 mM), and NaN3 (10 mM) were found to completely inhibit PvL. Sixty-eight percent of Malachite green was decolorized by 4 U/mL of PvL after 15 min incubation at 30 °C.     

Ondansetron enhanced diclofenac‐induced nephrotoxicity in mice

This study was performed to investigate the effect of ondansetron, a serotonin receptor (5‐HT3) antagonist, in the alleviation of diclofenac‐induced kidney injuries. NMRI mice were randomly divided into six groups and treated with (A) untreated control group, (B) diclofenac (100 mg/kg), (C) ondansetron (1 mg/kg), (D to F) ondansetron (0.1, 0.5, and 1 mg/kg, respectively) and diclofenac (100 mg/kg) for last 3 days of experiment. The oxidative stress tests strongly demonstrated the negative synergistic effects of diclofenac and ondansetron, regarding the observation of dose‐dependent enhancement of malondialdehyde concentration, and reduction of glutathione content, and superoxide dismutase and catalase activity. Histopathological analyses revealed dose‐dependent tubular epithelial cells degeneration, outstanding mononuclear cells infiltration, clear necrosis at the papillary region of kidney, dilation, and vascular hyperemia in mice kidney tissues treated with ondansetron and diclofenac. Conclusively, these findings suggested the possible ondansetron‐diclofenac interaction through the induction of oxidative stress.