Microbial gas vesicles as nanotechnology tools: exploiting intracellular organelles for translational utility in biotechnology, medicine and the environment

Abstract

<jats:p>A range of bacteria and archaea produce gas vesicles as a means to facilitate flotation. These gas vesicles have been purified from a number of species and their applications in biotechnology and medicine are reviewed here. <jats:italic> <jats:named-content content-type="genus"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.272" xlink:type="simple">Halobacterium</jats:ext-link> </jats:named-content> </jats:italic> sp. NRC-1 gas vesicles have been engineered to display antigens from eukaryotic, bacterial and viral pathogens. The ability of these recombinant nanoparticles to generate an immune response has been quantified both <jats:italic>in vitro</jats:italic> and <jats:italic>in vivo</jats:italic>. These gas vesicles, along with those purified from <jats:italic>Anabaena flos-aquae</jats:italic> and <jats:italic> <jats:named-content content-type="species"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.4942" xlink:type="simple">Bacillus megaterium</jats:ext-link> </jats:named-content> </jats:italic>, have been developed as an acoustic reporter system. This system utilizes the ability of gas vesicles to retain gas within a stable, rigid structure to produce contrast upon exposure to ultrasound. The susceptibility of gas vesicles to collapse when exposed to excess pressure has also been proposed as a biocontrol mechanism to disperse cyanobacterial blooms, providing an environmental function for these structures.</jats:p>

Archaeosomes and Gas Vesicles as Tools for Vaccine Development

“…Gas vesicles are small, inert, empty, proteinaceous intracellular organelles, produced by various microbes, including cyanobacteria, proteobacteria and halophilic and methanogenic archaea (36,39,40). In microorganisms inhabiting the water environment, gas vesicles play a role in the buoyancy of the cell, allowing it to adapt to environmental changes and to maintain access to oxygen and light required for ATP synthesis and optimal microbial growth (39)(40)(41). However, the role of gas vesicles in microorganisms such as methanogenic archaea or soil bacteria still remains unknown (36).…”

“…In the first stages of their biosynthesis, the vesicles are biconical and subsequently evolve into a cylindrical shape (39,40). Usually, gas vesicles are 0.045 -0.2 µm wide and 0.1 -2 µm long, but their exact size and shape are determined by environmental conditions, e.g.…”

“…Usually, gas vesicles are 0.045 -0.2 µm wide and 0.1 -2 µm long, but their exact size and shape are determined by environmental conditions, e.g. the higher the pressure, the narrower the gas vesicles (39). Gas vesicles consist only of proteins.…”

“…Gas vesicles consist only of proteins. The basic composition of the vesicle structure includes two proteins: small hydrophobic GvpA proteins (7-8 kDa) and large hydrophilic GvpC proteins (20-40 kDa) (39,40).…”

Microbial Musings – June 2020

“…This month we start the issue with an interesting review about gas vesicles in bacteria and archaea by Amy Hill and George Salmond from the University of Cambridge [1]. These intracellular protein-lined compartments are formed and matured through processes that are not fully understood.…”