The Hawaiian Archipelago: a microbial diversity hotspot

Area of Science:

• Microbiology
• Ecology
• Genetics

Background:

• Hawaiian Archipelago is a biodiversity hotspot with high endemism.
• Limited region-wide data on Hawaii's microbial communities.
• Diverse aquatic habitats across elevation and distance.

Purpose of the Study:

• To characterize the prokaryotic communities in Hawaiian aquatic environments.
• To identify novel microorganisms and understand their distribution.
• To investigate the relationship between habitat chemistry and microbial community structure.

Main Methods:

• Compiled 16S small subunit ribosomal DNA (SSU rDNA) clone libraries.
• Cultivated bacteria from lakes, an anchialine pool, and a submarine volcano.
• Analyzed sequence identity to define operational taxonomic units (OTUs) and culture groups.

Main Results:

• Each site hosted a distinct prokaryotic community, dominated by Bacteria.
• 158 bacterial phyla identified from clone libraries; 10 phyla from cultures.
• Only 7 operational taxonomic units (OTUs) were found at multiple sites.
• Community structure correlated with habitat chemistry (e.g., Proteobacteria distribution).
• Novel sequences extended the known geographic range of certain bacterial phyla.

Conclusions:

• Hawaiian aquatic habitats harbor unique and diverse microbial communities.
• Geographic isolation and habitat diversity drive microbial evolution.
• Significant proportion of novel sequences indicate undiscovered microbial diversity.