A prophage tail-like protein is deployed by Burkholderia bacteria to feed on fungi

Area of Science:

• Microbiology
• Bacteriology
• Mycology

Background:

• Mycophagy, the consumption of fungi by bacteria, is a poorly understood ecological interaction.
• The specific mechanisms by which bacteria achieve mycophagy remain largely elusive.

Purpose of the Study:

• To elucidate the molecular mechanisms underlying mycophagy in Burkholderia gladioli.
• To identify bacterial factors responsible for fungal cell wall degradation and nutrient acquisition from fungi.

Main Methods:

• Genetic disruption of the Bg_9562 gene in Burkholderia gladioli.
• Purification and functional assay of the Bg_9562 protein against various fungal species.
• Heterologous expression of Bg_9562 in Ralstonia solanacearum.
• Type III secretion system (T3SS) functional assays.

Main Results:

• The Bg_9562 protein was identified as essential for mycophagy in Burkholderia gladioli.
• Purified Bg_9562 induced hyphal disintegration and inhibited the growth of multiple fungal species.
• Disruption of the Bg_9562 gene abolished the bacterium's ability to perform mycophagy.
• Bg_9562, a T3SS effector, is translocated into fungal mycelia, conferring mycophagous ability in other bacteria.

Conclusions:

• The phage tail-like protein Bg_9562 is a key determinant of bacterial mycophagy, acting as a T3SS effector to degrade fungal structures.
• This mechanism allows Burkholderia gladioli to utilize fungi as a nutrient source, potentially aiding survival in specific environments.
• Bg_9562 exhibits broad-spectrum antifungal activity, suggesting potential biotechnological applications for controlling fungal diseases.