Diversity begets diversity under microbial niche construction

Abstract

Microbial interactions are expected to modulate microbial diversity, but whether they inhibit or stimulate further diversity in complex microbial communities, and how, remains poorly understood. By assembling microbial communities in multiple identical habitats with a single limiting nutrient, here we provide direct evidence for the role of microbial niche construction and cross-feeding in driving a positive relationship between community diversity and focal lineage diversity in microbial communities. Combining these experiments with simulations, we show that this positive relationship is not inevitable but depends on the underlying metabolic structure of by-product secretions and uptake between different taxonomic levels.