Biofilm Formation and Niche Adaptation Play Fundamental Role in Shaping Long-Distance Transported Dust Microbial Community

The long-distance transport of microorganisms via dust events is expected to become more prominent and intensified. At the same time, the survival mechanisms of air/dust-borne bacteria and their possible contribution to global processes remain poorly understood. In this study, we characterized Bacillus species from transitional season dust storms, previously identified as a significant component of the bioactive community of the dust microbiome. Our results demonstrated substantial growth and biofilm formation diversification, potentially linked to niche adaptation and surface-associated biofilm formation within heterogeneous dust particles. Most dust isolates form biofilms while exhibiting different preferences for media composition. Sterile dust induced biofilm formation, growth, matrix gene expression of B. subtilis, and robust biofilms in key related dust isolates. Overall, our results highlight the significance of biofilm formation as an adaptive mechanism in the distinct habitat of dust storms, with niche adaptation potentially playing a role in microenvironments within the dust particle. These results hold significant potential for implications on terrestrial and aquatic ecology and health, suggesting a pivotal process by which bacteria survive and evolve in this understudied habitat.