Cyanobacteria and Chloroflexota cooperate to structure light-responsive biofilms

Area of Science:

• Microbiology
• Ecology
• Biophysics

Background:

• Microbial mats are complex, stratified communities.
• Studying in situ responses to environmental gradients like light is challenging.
• Key members include unicellular cyanobacteria and filamentous phototrophs.

Purpose of the Study:

• To investigate cooperative motility and biofilm formation in a binary microbial consortium.
• To understand the role of individual species' motility in community behavior.
• To explore the ecological implications of interspecies cooperation in microbial mats.

Main Methods:

• Developed a binary consortium of Synechococcus OS-B' (Syn OS-B') and Chloroflexus MS-CIW-1 (Chfl MS-1).
• Quantified individual cell and colony motility using microscopy.
• Assessed biofilm formation and interspecies association via electron microscopy.

Main Results:

• Chfl MS-1 showed non-directional motility; Syn OS-B' exhibited positive phototaxis.
• The binary consortium displayed enhanced motility and formed ordered, light-aligned arrays.
• Cooperative motility required a functional pilB gene in Syn OS-B'.
• The consortium produced more adherent biofilm than individual species.

Conclusions:

• Cyanobacteria and Chloroflexota exhibit cooperative behavior in a binary consortium.
• This cooperation enhances motility, biofilm formation, and colonization potential.
• Interspecies cooperation is crucial for the structure and function of natural microbial mats.