A minireview on the in vitro and in vivo experiments with anti-Escherichia coli O157 : H7 phages as potential biocontrol and phage therapy agents

Phage therapy is an old method of combating bacterial pathogens that has recently been taken into consideration due to the alarming spread of antibiotic resistance. Escherichia coli 0157:H7 is a foodborne pathogen that causes hemorrhagic colitis and life-threatening Hemolytic Uremic Syndrome (HUS). There are several studies on isolation of specific phages against E. coli 0157:H7 and more than 60 specific phase have been published so far. Although in vitro experiments have been successful in elimination or reduction of E. coli 0157:H7numbers, in vivo experiments have not been as promising. This may be due to escape of bacteria to locations where phages have difficulties to enter or due to the adverse conditions in the gastrointestinal tract that affect phage viability and proliferation. To get around the latter obstacle, an alternative phage delivery method such as polymer microen-capsulation should be tried. While the present time results are not very encouraging the work should be continued as more efficient phage treatment regimens might be found in future. (C)2016 Elsevier B.V. All rights reserved.Peer reviewe

Isolation and molecular identification of halophilic protease producing actinomycete and evaluation of effective factors for maximal enzyme production

Introduction: Proteases are one of the most applicable hydrolyzing enzymes especially in food and beverage industries. Isolation of thermophilic or halophilic proteases was aimed by many investigations. The present study was designed to screen soil samples for halophilic actinomycetes capable to produce protease and evaluation of factors affect on the enzyme production.  Methods: Twenty soil samples were collected from salty land around Kerman, Iran and aseptically transferred to biotechnology lab and allowed to dry. Ten grams of each soil was extracted using NaCl (0.9%) sterile solution and added to Casein Glycerol Agar (CGA) or nutrient agar medium containing skim milk (1%) and NaCl (10%) and incubated at 30◦C untill the halo zone of protease activity was formed. The ratio of halo zone/colony size of isolated actinomyctes was used as an index to select the most suitable strains. Morphological and biochemical tests as well as molecular identification using 16S rDNA technique were then applied for identification of the strain. Evaluation of chemical factors such as carbon sources, nitrogen sources and inorganic salts as well as physical factors such as temperature and pH on protease production of the selected strain was performed using one factor at a time approach. Results: Seven protease-producing actinomycetes were isolated in preliminary studies among which one isolate (identified as Nocardiopsis sp.) was the most efficient one able to produce 650 U/mL protease after 5 days incubation in CG medium containing 10% NaCl. Evaluation of factors is now conducting to obtain the maximum protease production. Conclusion: one halophilic actinomycete able to produce protease was isolated in the present study and evaluation of factors affect on the enzyme production is now performing

Preparation and evaluation of the effect of Fe3O4@piroctone olamine magnetic nanoparticles on matrix metalloproteinase-2: A preliminary in vitro study

In the present study, Fe3O4 magnetic nanoparticles were synthesized by the coprecipitation of Fe2+ and Fe3+ ions and used as a nanocarrier for the production of piroctoneolamine- loaded Fe3O4 nanoparticles (Fe3O4@PO NPs). The nanocrystalline structure of the prepared iron oxide species was confirmed by the X-ray diffraction spectroscopy method. Particle size distribution analysis showed that the size of Fe3O4@PO NPs was in the range of 5–55 nm. The magnetization curve of Fe3O4@PO NPs (with saturation magnetization of 28.2 emu/g) confirmed its ferromagnetic property. Loading of PO on the surface of Fe3O4 NPs qualitatively verified by Fourier transform infrared spectrum obtained from Fe3O4@PO NPs. Cytotoxicity studies on the human fibrosarcoma cell line (HT-1080) revealed higher inhibitory effect of Fe3O4@PO NPs (50% cell death [IC50] of 8.1 μg/mL) as compared with Fe3O4 NPs (IC50 of 117.1 μg/mL) and PO (IC50 of 71.2 μg/mL) alone. In the case of human normal fibroblast (Hs68), the viability percentage was found to be 75% in the presence of Fe3O4@PO NPs (120 μg/mL). Gelatin zymography showed 17.2% and 34.6% inhibition of matrix metalloproteinase-2 (MMP-2) in the presence of Fe3O4@PO and PO, respectively, at the same concentration of 40 μg/mL, whereas Fe3O4 NPs did not inhibit MMP-2 at any concentration. C� 2014 International Union of Biochemistry and Molecular Biology, Inc. Volume 61, Number 6, Pages 676–682, 201

RESEARCH AND REVIEWS: JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY Biosynthesis and Characterization of Selenium Nanoparticles Produced by Terrestrial Actinomycete Streptomyces microflavus Strain FSHJ31

ABSTRACT During last decades, study on the development of eco-friendly processes for the production of selenium nanoparticles (Se NPs) have received much attention due to hazardous effects of chemical compounds used for nanoparticle preparation. The present study was designed to screen actinomycete strains able to produce Se NPs. Among isolated bacterial strains, a terrestrial actinomycete strain which was tolerant to Se 4+ ions (200 µg/ml of) was launched as Se NPs producer. Morphological and biochemical characteristics as well as 16S rDNA gene analysis of the selected strain introduced it as Streptomyces microflavus strain FSHJ31. The biologically synthesized Se NPs was then purified using n-Octyl alcohol/water extraction system and characterized by UV-vis spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FTIR) techniques. Analysis of the particle size distribution pattern of biogenic Se NPs via laser light scattering method demonstrated the size range of 28-123 nm for Se NPs with the 48 nm NPs being the most frequent particles

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

Microbial-assisted synthesis and evaluation the cytotoxic effect of tellurium nanorods

The present study was designed to isolate bacterial strain capable of tellurium nanorods' (Te NRs) production followed by purification and evaluation of the cytotoxic effect of Te NRs. Among 25 environmental samples collected for screening of Te NR-producer bacterial strains one bacterial colony (isolated from hot spring and identified as Pseudomonas pseudoalcaligenes strain Te)was selected and applied for biosynthesis of TeNRs. Thereafter, an organic–aqueous partitioning system was applied for the purification of the biogenic Te NRs and the purified TeNRswere characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction spectroscopy (XRD), UV–visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR) techniques. The cytotoxic effect of biologically synthesized Te NRs and potassium tellurite on four cell lines of MCF-7, HT1080, HepG2 and A549 was then determined using theMTT assay method. The obtained results revealed lower toxicity for the rod-shaped biogenic tellurium nanostructures (~22 nm diameter by 185 nm length) compared to K2TeO3

Thermoalkalophilic lipase from an extremely halophilic bacterial strain <i>Bacillus atrophaeus</i> FSHM2: Purification, biochemical characterization and application

<p>The present study was designed to isolate and identify an extremely halophilic lipase-producing bacterial strain, purify and characterize the related enzyme and evaluate its application for ethyl and methyl valerate synthesis. Among four halophilic isolates, the lipolytic ability of one isolate (identified as <i>Bacillus atrophaeus</i> FSHM2) was confirmed. The enzyme (designated as <i>Ba</i>L) was purified using three sequential steps of ethanol precipitation and dialysis, Q-Sepharose XL anion-exchange chromatography and SP Sepharose cation-exchange chromatography with a final yield of 9.9% and a purification factor of 31.8. The purified <i>Ba</i>L (Mw∼85 kDa) was most active at 70 °C and pH 9 in the presence of 4 M NaCl and retained 58.7% of its initial activity after 150 min of incubation at 80 °C. The enzyme was inhibited by Cd²⁺ (35.6 ± 1.7%) but activated by Ca²⁺ (132.4 ± 2.2%). Evaluation of <i>Ba</i>L's stability in the presence of organic solvents showed that xylene (25%) enhanced the relative activity of the enzyme to 334.2 ± 0.6% after 1 h of incubation. The results of esterification studies using the purified <i>Ba</i>L revealed that maximum ethyl valerate (88.5%) and methyl valerate (67.5%) synthesis occurred in the organic solvent medium (xylene) after 48 h of incubation at 50 °C.</p