Evidence for a central ecological function of predatory Myxococcota in soil ecosystems

Abstract

Myxococcota is a recently classified phylum including bacteria renowned for their predatory lifestyle. However, ecological functions of these bacteria remain under studied. Here, we examined the ecological position and potential impact of Myxococcota communities across diverse soil habitats using the global geographical collection of 16S microbial communities structured by the Earth Microbiome Project (EMP). First, we found that the abundance of Myxococcota varied greatly from 6.3% to 0.8% across 13 soil habitats. A deeper microbial analysis in two selected habitats showed that Myxococcota was highly abundant (4.9%) ranking 5 in field soil (a grassland planted with switchgrass) than in sand biofilter (an engineered system for water quality production, 1.3% and 11, resp.). Moreover, both Myxococcota and microbial communities displayed a significantly higher -diversity in field soil than in sand biofilter environments, suggesting that diversity of Myxococcota seems to be associated with that of microbial communities in these habitats. Using co-occurrence network analysis, we found that Myxococcota exhibited a high eigenvector centrality (5.1%) and one hub taxon, Polyangiales, in field soil habitat. In contrast, Myxococcota centrality was less pronounced (1.1%) in the sand biofilter, where consistent negative correlations were also detected. Altogether, these results suggest that Myxococcota communities experienced beneficial interactions in field soil environment, whereas they may have faced competitive relationships in sand biofilter habitat. Overall, our findings provide further insights into the status of Myxococcota communities in soil environments, suggesting their fundamental roles in the structure of soil microbial communities.