The community, assembly process and potential functions of bacteria with different cell size in a river

Cell size regulates the evolution and selection of bacterial metabolic strategies through the "resource acquisition capacity-metabolic cost trade-off", resulting in significant differences in community and metabolic functions among bacteria with different size. Therefore, phenotypic grouping of bacterial communities based on cell size can directly establish the mechanism connection between the "phenotypic structure" of microbial communities and ecological function, which has significant theoretical significance for clarifying the role and status of bacteria of different cell sizes in the biogeochemical cycle process.

The results showed that UB and LB were clearly distinguishable in the environment, and their relative proportions varied with environmental conditions. Compared with LB, UB exhibited lower diversity and narrower ecological niche breadth, the community compositions of the two groups showed significant differences, leading to distinct ecological functions. Notably, UB play a crucial role in material cycling, contributing to the maintenance of ecosystem balance and stability, and participating actively in elemental cycles.

Our findings highlight the utility of cell size as an indicator of bacterial diversity and reveal a direct link between microbial morphology and ecological characteristics.