Partial Purification and Characterization of a Thermoalkalophilic Lipase Originated from Bacillus atrophaeus FSHM2 and its Application for Ester Synthesis

A thermoalkalophilic lipase producing bacterial strain, identified as Bacillus atrophaeus FSHM2 using 16S rDNA sequencing analysis was isolated from salty soil and its lipase was partially purified and characterized. The obtained results revealed that glucose, hazelnut oil, urea and calcium ion positively affected the lipase production by increasing the lipolytic activity to 13582.5, 6270, 4442 and 5505 U LG1, respectively compared to that of basal medium (4150 U LG1). The partially purified lipase acted optimally at pH 9 and retained 88.2% of its initial activity after 1 h of incubation at 100°C. A two fold increase in the relative activity of the partially purified lipase was obtained in the presence of 4 M of NaCl. Application of the partially purified lipase for the synthesis of ethyl and methyl valerate in the organic solvent medium (xylene) resulted in 81.6 and 62.4% esterification, respectively, after 24 h of incubation

Antimicrobial, anti-biofilm, and anti-proliferative activities of lipopeptide biosurfactant produced by Acinetobacter junii B6

Lipopeptide biosurfactants (LPBs) are amphiphilic compounds produced by microorganisms exhibiting various biological activities. The main aim of the present study was to assess the in vitro antimicrobial, anti-biofilm, and cytotoxic effects of LPB produced by Acinetobacter junii (AjL). We determined AjL minimum inhibitory concentration (MIC) against both Gram-positive and Gram-negative bacteria as well as two fungal strains. Also, the anti-biofilm activity of AjL against the biofilm produced by clinically isolated bacterial strains was investigated. The AjL non-selectively showed activity against both Gram-positive and Gram-negative bacterial strains. The obtained results of the present study exhibited that the AjL in concentrations nearly below critical micelle concentration (CMC) has an effective antibacterial activity. It was found that the MIC values of AjL were lower than standard antifungal and it exhibited nearly 100 inhibition against Candida utilis. The attained results of the biofilm formation revealed that AjL disrupted the biofilm of Proteus mirabilis, Staphylococcus aureus, and Pseudomonas aeruginosa at 1250 μg/ml and 2500 μg/ml concentrations. The attained results of cytotoxic effect (determined by WST-1 assay) of the AjL revealed IC50 of 7.8 ± 0.4 mg/ml, 2.4 ± 0.5 mg/ml, and 5.7 ± 0.1 mg/ml, against U87, KB, and HUVEC cell lines, respectively. The results indicated that AjL has a potential application in the relatively new field of biomedicine. © 2019 Elsevier Lt

Rapid and Facile Microwave-Assisted Synthesis of Palladium Nanoparticles and Evaluation of Their Antioxidant Properties and Cytotoxic Effects Against Fibroblast-Like (HSkMC) and Human Lung Carcinoma (A549) Cell Lines

We report here a simple microwave irradiation method (850 W, 3 min) for the synthesis of palladium nanoparticles (Pd NPs) using ascorbic acid (as reducing agent) and sodium alginate (as stabilizer agent). The synthesized nanoparticles were characterized using transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray diffraction spectroscopy (XRD), UV-Visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR) techniques. Antioxidant properties and cytotoxic effects of as-synthesized Pd NPs and Pd (II) acetate were also assessed. UV-Vis study showed the formation of Pd NPs with maximum absorption at 345 nm. From TEM analysis, it was observed that the Pd NPs had spherical shape with particle size distribution of 13�33 nm. Based on DPPH radical scavenging activity and reducing power assay, the antioxidant activities of Pd NPs were significantly higher than the Pd (II) acetate (p < 0.05). At the same concentration of 640 μg/mL, the scavenging activities were 32.9 ± 3.2 (Pd (II) acetate) and 27.2 ± 2.1 (Pd NPs). For A549 cells treated 48 h with Pd NPs, Pd (II) acetate, and cisplatin, the measured concentration necessary causing 50 cell death (IC50) was 7.2 ± 1.7 μg/mL, 32.1 ± 2.1 μg/mL, and 206.2 ± 3.5 μg/mL, respectively. On HSkMC cells, the IC50 of the Pd NPs (320 μg/mL) was higher compared to Pd (II) acetate (228.7 ± 3.6 μg/mL), which confirmed lower cytotoxicity of the Pd NPs. © 2019, Springer Science+Business Media, LLC, part of Springer Nature

α‐Fe2O3@Ag and Fe3O4@Ag Core‐Shell Nanoparticles: Green Synthesis, Magnetic Properties and Cytotoxic Performance

Abstract This work provides the synthetic route for the arrangement of Fe3O4@Ag and α‐Fe2O3@Ag core‐shell nanoparticles (NPs) with cytotoxic capabilities. The production of Fe3O4@Ag and α‐Fe2O3@Ag core‐shell NPs was facilitated utilizing S. persica bark extracts. The results of Powder X‐ray Diffraction (PXRD), Ultraviolet‐visible (UV‐Vis) spectroscopy, Vibrating Sample Magnetometry (VSM), Energy Dispersive X‐ray (EDX) analysis, Field Emission Scanning Electron Microscopy (FESEM), and Transmission Electron Microscopy (TEM) supported the green synthesis and characterization of Fe3O4@Ag and α‐Fe2O3@Ag NPs. The particle size was measured by the TEM analysis to be about 30 and 50 nm, respectively; while the results of FESEM showed that α‐Fe2O3@Ag and Fe3O4@Ag particles contained multifaceted particles with a size of 50–60 nm and 20–25 nm, respectively. The outcomes of VSM were indicative of a saturation magnetization of 37 and 0.18 emu/g at room temperature, respectively. The potential cytotoxicity of the synthesized core‐shell nanoparticles towards breast cancer (MCF‐7) and human umbilical vein endothelial (HUVEC) cells was evaluated by an MTT assay. α‐Fe2O3@Ag NPs were able to destroy 100 % of MCF‐7 cell at doses above 80 μg/mL, and it was confirmed that Fe3O4@Ag NPs at a volume of 160 μg/mL can destroy 90 % of MCF‐7 cells. Thus, the applicability of the prepared nanoparticles of these nanoparticles in biological and medical fields has been demonstrated