Podcast: Basic Guidelines for Bacteriophage Isolation and Characterization

Author(s): Safia Samir*


The world is on the cusp of a post-antibiotic period. A century ago, before the advent of antibiotics, bacteriophage therapy was the treatment of choice for bacterial infections. Although bacteriophages have yet to be approved as a treatment in Western medicine, researchers and clinicians have begun to anticipate phage therapy. Bacteriophages are viruses that depend on bacterial cell metabolism to multiply. They offer a promising alternative to the use of antibiotics and an excellent antibacterial option for combating multidrug resistance in bacteria. However, not every phage is suitable for phage therapy. In particular, prophages should not be used because they can lysogenize host cells instead of lysing them. To offer adequate therapeutic options for patients suffering from various infectious diseases, a wide selection of different phages is needed. While there is no evidence of direct toxicity induced by phage particles, it is crucial to study mammalian cell–phage interactions. This requires phage preparations to be free of bacterial cells, toxins and other compounds to avoid skewing host responses. Negative staining of purified viruses and electron microscopy remain the gold standard in the identification of bacteriophages. Interestingly, genomics has greatly changed our understanding of phage biology. Bacteriophage genome sequencing is essential to obtain a complete understanding of the bacteriophages’ biology and to obtain confirmation of their lifestyle. Full genetic sequencing of bacteriophage will enable a better understanding of the phage-encoded proteins and biomolecules (especially phage lytic enzymes) involved in the process of bacterial cell lysis and death. Mass spectrometry can be used for the identification of phage structural proteins. The use of lytic phages as biocontrol agents requires the most appropriate and standard methods to ensure application safety. This review pursues recent research and methods in molecular biology for the isolation and characterization of phages to facilitate follow-up and implementation of work for other researchers. Patents related to this topic have been mentioned in the text.

Journal link: http://bit.ly/3GraUct

Podcast: http://bit.ly/3k2E0qY

Editor’s choice: Synthesis of Hexahydroxy Strontium Stannate/Tin Dioxide Nanocomposites and their Photocatalytic Properties for Gentian Violet

Author(s):Chunhu YuZeyang XueYajing MaoJianfeng Huang, Feihu TaoZhengyu CaiChuangang Fan and Lizhai Pei*

Background: Gentian violet dye released from industries into the environment has caused serious water pollution and is a significant environmental pollutant to human beings owing to the toxicity. It is urgent to decrease environmental pollution by removing gentian violet in the wastewater.

Objective: The aim is to synthesize hexahydroxy strontium stannate/tin dioxide nanocomposites by a simple hydrothermal method without surfactants and research the photocatalytic performance for gentian violet degradation.

Methods: Hexahydroxy strontium stannate/tin dioxide nanocomposites have been obtained via the hydrothermal method. The structure, size, morphology and photocatalytic performance were characterized by X-ray diffraction, electron microscopy, solid ultraviolet-visible diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy.

Results: The nanocomposites possess oven-shaped morphology with the size of less than 100 nm and are composed of hexagonal SrSn(OH)and tetragonal SnO2 phases. The band gap of the nanocomposites is 3.52 eV. 10 mg hexahydroxy strontium stannate/tin dioxide nanocomposites have the ability to completely degrade 10 mL gentian violet solution with the concentration of 10 mgL-1 under 6 h ultraviolet-visible light irradiation. Hydroxyl radical, hole and superoxide radical are the main species for the gentian violet photocatalytic degradation using the nanocomposites.

Conclusion: The hexahydroxy strontium stannate/tin dioxide nanocomposites show good photocatalytic performance for the GV degradation. The photocatalytic performance for gentian violet degradation using the hexahydroxy strontium stannate/tin dioxide nanocomposites depends on the irradiation time and content of the nanocomposites.

Read more: https://bit.ly/3hFj7Bi

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