Predicting Species-Resolved Macronutrient Acquisition during Succession in a Model Phototrophic Biofilm Using an...

Area of Science:

• Microbiology
• Ecology
• Biogeochemistry

Background:

• Nutrient acquisition and exchange principles in microbial communities are poorly understood.
• Interspecies nutrient exchange significantly impacts overall community productivity.
• Understanding these dynamics is crucial for predicting microbial ecosystem functions.

Purpose of the Study:

• To investigate energy and macronutrient acquisition in unicyanobacterial consortia.
• To analyze species-specific gene expression related to resource acquisition during community succession.
• To determine how nutrient limitations structure microbial communities.

Main Methods:

• Utilized multi-omic approaches on unicyanobacterial consortia with complete genome information.
• Performed metabolic reconstruction to predict species' resource acquisition capabilities.
• Examined gene expression patterns of resource-acquisition proteins over a 28-day period.

Main Results:

• Most heterotrophic members lacked genes for direct inorganic nutrient acquisition, indicating high metabolic interdependency.
• The primary producer, *Phormidium* sp. OSCR, showed decreased expression of energy and carbon fixation proteins but increased phosphate transporter expression.
• Both the primary producer and heterotrophs exhibited signs of phosphorus starvation, while heterotrophs displayed species-specific nitrogen acquisition gene expression.

Conclusions:

• Phosphate limitation structures microbial communities by promoting niche partitioning around nitrogen acquisition.
• Niche complementarity in nitrogen acquisition can enhance microbial community diversity and productivity.
• Metabolic interdependency is a key feature of these microbial consortia, particularly under nutrient stress.