Eleventh Meeting
Date: Saturday, 24 July 02021
Time: 19:00 (UTC+2)
Place: Jitsi Meeting Room (video call)
Duration: 60 minutes
Language: English
As far as I can recall, we’ve yet to read a paper dealing with fungal - bacterial interactions. I stumbled upon just such a paper yesterday, one which deals with collaborative microbial transport.
Here’s my simplistic rendering of the relationship described by the paper:
Conidia (nonmotile asexual fungal spores) of the fungus Aspergillus fumigatus are carried by the swarming bacterium Paenibacillus vortex. The bacteria rescue and transport the spores away from adverse conditions. This aids in fungal dispersal. When encountering an impassable air gap, the bacterial swarm releases the fungal spores which then germinate and form a mycelial bridge; the bacteria cross the bridge.
Ingham CJ, Kalisman O, Finkelshtein A, Ben-Jacob E (2011). Mutually facilitated dispersal between the nonmotile fungus Aspergillus fumigatus and the swarming bacterium Paenibacillus vortex. Proceedings of the National Academy of Sciences, 108(49):19731-6.
Link to the open-access paper (PDF)
Link to a popular science summary of the paper on ScienceDaily
Abstract:
In the heterogeneous environment surrounding plant roots (the rhizosphere), microorganisms both compete and cooperate. Here, we show that two very different inhabitants of the rhizosphere, the nonmotile fungus Aspergillus fumigatus and the swarming bacterium Paenibacillus vortex, can facilitate each other’s dispersal. A. fumigatus conidia (nonmotile asexual fungal spores) can be transported by P. vortex swarms over distances of at least 30 cm and at rates of up to 10.8 mm h−1. Moreover, conidia can be rescued and transported by P. vortex from niches of adverse growth conditions. Potential benefit to the bacteria may be in crossing otherwise impenetrable barriers in the soil: fungal mycelia seem to act as bridges to allow P. vortex to cross air gaps in agar plates. Transport of conidia was inhibited by proteolytic treatment of conidia or the addition of purified P. vortex flagella, suggesting specific contacts between flagella and proteins on the conidial surface. Conidia were transported by P. vortex into locations where antibiotics inhibited bacteria growth, and therefore, growth and sporulation of A. fumigatus were not limited by bacterial competition. Conidia from other fungi, similar in size to those fungi from A. fumigatus, were not transported as efficiently by P. vortex. Conidia from a range of fungi were not transported by another closely related rhizosphere bacterium, Paenibacillus polymyxa, or the more distantly related Proteus mirabilis, despite both being efficient swarmers.
This will be our last meeting before the review meeting, during which we will reflect on the 11 papers read thus far
Hope to see some of you there!