Environmental sensing capacity predicts bacterial ecological strategies and environmental preferences

Environmental sensing plays a crucial role in the success of bacteria in their ecological niches. Bacteria possess sensor domains that allow them to perceive nutrients, other organisms, and physical conditions in their surroundings. However, it is unclear if these sensing systems reflect evolutionary specialization. In this study, researchers examined sensor domains present in 51,343 bacterial genomes and 255 soil metagenomes from various climates to investigate if sensory repertoires indicate ecological strategies and preferences.

The results showed that sensory repertoires were highly conserved across different bacteria and displayed signs of genome simplification, suggesting that maintaining complex sensory systems comes with trade-offs. Environments with more variability and free-living aerobic bacteria were associated with larger sensory repertoires, implying a need for enhanced information processing to adapt to changing conditions.

By analyzing ligand-binding motifs (LBMs) across genomes and metagenomes, the researchers found that distinct LBM profiles could differentiate host-associated and free-living bacteria, as well as aerobic and anaerobic lineages, and generalists and non-generalists. This indicates a strong connection between the ability to sense the environment and the bacteria's ecological role.

Furthermore, specific LBM profiles were enriched in soil communities under conditions of increasing drought, demonstrating that sensory functions are directly influenced by environmental factors. The findings emphasize environmental sensing as a key factor in shaping bacterial trait-based ecology, integrating evolutionary history, ecological lifestyles, and adaptation to local conditions.

Considering the role of environmental sensing in predicting microbial niches and responses to environmental changes is essential.