Bacteria-archaea metabolic complementarity as a driver of ecosystem functioning in Chinese coastal sediments

Area of Science:

• Marine microbiology
• Biogeochemistry
• Sedimentary ecology

Background:

• The East China Sea (ECS) harbors diverse microbial life in its shallow sediments.
• Microbial communities are shaped by complex environmental factors like river discharge and human activities.

Purpose of the Study:

• To characterize the vertical distribution of bacterial and archaeal communities in ECS sediments.
• To identify key environmental drivers influencing microbial community structure and function.

Main Methods:

• 16S rRNA gene high-throughput sequencing was employed.
• Environmental parameters were analyzed across three sediment depth intervals (50m, 50-100m, 100-200m).
• Multivariate statistics and co-occurrence network analysis were used.

Main Results:

• Organic carbon, oxygen, and sulfur availability were identified as key drivers of microbial community structure.
• Bacteria dominate oxidative processes (nitrogen/sulfur cycling, organic matter degradation).
• Archaea, particularly Bathyarchaeia, specialize in anaerobic methanogenesis and reductive pathways.

Conclusions:

• Distinct ecological divergence exists between bacterial and archaeal communities in ECS sediments.
• Functional complementarity between prokaryotes sustains integrated biogeochemical cycling.
• This study enhances understanding of microbial responses to vertical environmental gradients and their ecological roles in coastal sediments.