User:Ykgbmn/sandbox

Original- "Gas vesicles"

Role in ultrasonic algaecide
Ultrasonic algae killing devices mode of action in blue-green algae is likely rupturing the cell's gas vesicles and causing the cells to lose buoyancy and sink to the bottom where they can no longer photosynthesize.

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Edits- "Gas vesicles"

Regulation
Formation of gas vesicles are regulated by two proteins: GvpD, which represses the expression of GvpA and GvpC proteins, and GvpE, which induces expression. Extracellular environmental factors also affect vesicle formation, either by regulating Gvp protein production or by directly disturbing the vesicle structure.

Light intensity
Light intensity has been found to affect gas vesicles production and maintenance differently between different bacteria and archaea. For Anabaena flos-aquae, higher light intensities leads to vesicle collapse from an increase in turgor pressure and greater accumulation of photosynthetic products. In cyanobacteria, vesicle production decreases at high light intensity due to exposure of the bacterial surface to UV radiation, which can damage the bacterial genome.

Carbohydrates
Accumulation of glucose, maltose, or sucrose in Haloferax mediterranei and Haloferax volcanii were found to inhibit the expression of GvpA proteins and, therefore, a decrease of gas vesicle production. However, this only occurred at the cell’s early exponential growth phase. Vesicle formation could also be induced in decreasing extracellular glucose concentrations.

Oxygen
A lack of oxygen was found to negatively affect gas vesicle formation in halophilic archaea. Halobacterium salinarum produce little or no vesicles under anaerobic conditions due to reduced synthesis of mRNA transcripts encoding for Gvp proteins. H. mediterranei and H. volcanii do not produce any vesicles under anoxic conditions due to a decrease in synthesized transcripts encoding for GvpA and truncated transcripts expressing GvpD.

pH
Increased extracellular pH levels have been found to increase vesicle formation in Microcytis species. Under increased pH, levels of of gvpA and gvpC transcripts increase, allowing more exposure to ribosomes for expression and leading to upregulation of Gvp proteins. It may be attributed to greater transcription of these genes, decreased decay of the synthesized transcripts or the higher stability of the mRNA.

Ultrasonic irradiation
Ultrasonic irradiation, at certain frequencies, was found to collapse gas vesicles in cyanobacteria Spirulina platensis, preventing them from blooming.

Ykgbmn (talk) 06:56, 9 October 2017 (UTC)