Myxobacteria: social, gliding soil bacteria that form multicellular fruiting bodies

Key characteristics

At the cellular level myxobacteria glide across surfaces rather than swim and typically move as part of dense swarms that cooperate to find and digest food. Many species possess relatively large genomes compared with typical bacteria, encoding extensive regulatory networks and biosynthetic pathways; genomic overviews are available at genome databases. They are Gram-negative in cell envelope structure (Gram-negative references).

• Habitat: primarily soil and decaying organic matter (soil ecology).
• Motility: surface gliding using distinct mechanisms (gliding motility).
• Sociality: swarm formation, cell–cell signaling and coordinated enzyme secretion (swarming behaviour, signalling systems).
• Development: formation of fruiting bodies and resistant spores.

Movement and predation

Myxobacteria display two complementary gliding modes. "Adventurous" motility allows individual cells to move, while "social" motility depends on type IV pili and interactions between cells. In swarms they secrete extracellular enzymes and secondary metabolites to lyse and consume insoluble organic substrates and other microorganisms; coordinated secretion is described in studies on extracellular enzymes (enzyme secretion).

Life cycle and multicellularity

When nutrients are limiting, myxobacterial populations undergo a developmental program: cells aggregate into three-dimensional fruiting bodies inside which some cells differentiate into myxospores, dormant and stress-resistant forms. This multicellular behaviour has made certain species, such as Myxococcus xanthus, models for studying bacterial development and multicellularity (developmental biology).

Ecological roles and applications

Ecologically, myxobacteria contribute to decomposition and nutrient cycling by breaking down complex organic matter in soils. They are also predators of other microbes, shaping microbial communities. Their large repertoires of secondary metabolites include molecules with antibiotic or antifungal activity, which has attracted interest for natural product discovery and biotechnology.

Research significance and notable facts

Because of their complex social behaviours, genetic tractability in certain species, and rich biosynthetic potential, myxobacteria are subjects of active research in microbiology, ecology and drug discovery. For accessible summaries and further reading see overview resources (overview) and focused reviews on social behaviour (cell signalling) and swarming (swarm dynamics).

Further technical and genomic resources are maintained in specialized databases and repositories (genomic data, environmental data, cell envelope studies). Research continues to reveal how relatively simple cells coordinate complex multicellular programs and produce chemically diverse metabolites with potential applications.