Predetermined clockwork microbial worlds: Current understanding of aquatic microbial diel response from model systems...

Area of Science:

• Microbial Ecology
• Aquatic Ecosystems
• Biogeochemistry

Background:

• Microorganisms and viruses form complex food webs in aquatic photic zones.
• Phototrophic microbes like algae and cyanobacteria generate circadian rhythms via sunlight.
• Diel cycles in phototrophs influence heterotrophic microbes through excreted products and biotic interactions.

Purpose of the Study:

• To investigate the role of sunlight and photosynthesis in generating and propagating diel cycling within microbial communities.
• To understand how complex biotic interactions transmit diel rhythms through aquatic food webs.
• To explore the influence of viral lysis and grazing on diel cycling in heterotrophic microorganisms.

Main Methods:

• Observational studies in aquatic ecosystems.
• Analysis of microbial interactions and food web dynamics.
• Investigation of diel rhythm transmission pathways.

Main Results:

• Diel cycling originates in phototrophic microorganisms and is transmitted to heterotrophs.
• Viral lysis and protistan grazing contribute to dissolved organic matter, creating diel cycles in other heterotrophs.
• Complex interactions lead to variations and time lags in diel rhythms among different heterotrophic taxa.

Conclusions:

• Sunlight and photosynthesis are primary drivers of diel cycling in aquatic microbial communities.
• Complex biotic interactions mediate the propagation of diel rhythms throughout the food web.
• Understanding these diel cycles is crucial for comprehending aquatic ecosystem functioning.