Nitrogen cycling in corals: the key to understanding holobiont functioning?

Area of Science:

• Marine biology
• Microbiology
• Symbiosis

Background:

• Corals form vital reef ecosystems through symbiosis with algae (Symbiodinium).
• The coral microbiome (bacteria, archaea, fungi, viruses) plays a key role in holobiont function.
• Algal symbiont density depends on nitrogen availability, highlighting the importance of nitrogen-cycling microbes.

Purpose of the Study:

• To review current knowledge on nitrogen cycling within coral holobionts.
• To explore the link between nitrogen-cycling microbes and coral-algae symbiosis stability.
• To investigate the role of microbial nitrogen cycling in coral health under varying nutrient conditions.

Main Methods:

• Literature review and synthesis of existing research on coral nitrogen cycling.
• Analysis of the impact of nutrient availability on coral-algae symbiosis.
• Examination of microbial roles in coral holobiont functioning.

Main Results:

• Nitrogen-cycling microbes are fundamental to maintaining the coral-algae symbiosis.
• Microbial nitrogen cycling is critical for coral holobiont stability, especially under nutrient stress.
• Disruptions in microbial nitrogen cycling are strongly associated with coral bleaching and disease.

Conclusions:

• The coral microbiome, particularly nitrogen-cycling microbes, is essential for coral reef health.
• Understanding microbial nitrogen cycling is key to addressing coral bleaching and disease.
• Future research should focus on the intricate roles of nitrogen-cycling microbes in coral symbiosis.