Characterization of putative circular plasmids in sponge-associated bacterial communities using a selective...

Area of Science:

• Microbiology
• Genomics
• Marine Biology

Background:

• Plasmid transfer significantly impacts bacterial ecological adaptation and host interactions.
• Characterizing plasmids in complex microbial communities, like sponge symbionts, is challenging.

Purpose of the Study:

• To develop and validate a novel method for enriching and characterizing circular plasmid DNA from sponge microbial symbionts.
• To investigate the plasmidome of sponge-associated bacteria and identify novel genetic elements.

Main Methods:

• Development of a selective multiply-primed rolling circle amplification (smRCA) technique.
• Application of smRCA followed by random hexamer primer reamplification and high-throughput sequencing (HTS).
• Utilized DNA from sponge (Cinachyrella sp.) and isolated bacterial symbiont (Vibrio sp. CyArs1).

Main Results:

• Successfully amplified and characterized circular plasmids from sponge microbial communities and isolates.
• Detected plasmids associated with Vibrio sp. CyArs1 and numerous small (<2 kbp) cryptic plasmids.
• Identified plasmid-encoded proteins involved in replication and maintenance, alongside many unknown genes.

Conclusions:

• The smRCA-HTS approach effectively enriches and characterizes plasmid DNA from diverse bacterial sources, including sponge symbionts.
• The study revealed a rich source of unknown genetic information and potential novel replication systems within sponge plasmidomes.
• This method advances the study of microbial community plasmids and their ecological roles.