Bacterial membrane vesicle release triggered by dramatic interfacial electron transfer between diatoms and water

Area of Science:

• Biotechnology
• Materials Science
• Microbiology

Background:

• Diatoms exhibit genomic similarity with heterokonts, suggesting horizontal gene transfer potential.
• Diatom biosilica (DBs) were previously used for rapid, lysis-free pathogenic bacterial DNA extraction.
• This extraction was hypothesized to involve reactive oxygen species (ROS) and bacterial membrane vesicle (BMV) formation.

Purpose of the Study:

• To elucidate the mechanism of rapid interfacial ROS generation by DBs.
• To investigate how modifying DBs affects ROS production and DNA extraction efficiency.
• To explore the role of interfacial electron transfer in ROS generation and BMV formation.

Main Methods:

• DBs were modified by depositing cerium and calcium oxides onto their surfaces.
• Interfacial ROS production was measured and compared between modified and pristine DBs.
• BMV formation was assessed via protein concentration.
• Bacterial oxidative stress was analyzed using gene expression and transcriptomic profiles.
• DNA extraction efficiency was evaluated using PCR C_t values.

Main Results:

• Cerium-deposited DBs (Ce-DBs) exhibited higher reduction potentials, significantly increasing interfacial ROS by 610.69%.
• Ce-DBs induced a 23.08% increase in BMV protein concentration compared to pristine DBs.
• Gene expression and transcriptomic data confirmed the role of interfacial electron transfer in bacterial oxidative stress.
• Ce-DBs demonstrated superior DNA extraction efficiency, indicated by lower PCR C_t values.

Conclusions:

• The study elucidates the mechanism of rapid interfacial ROS generation by DBs, driven by interfacial electron transfer.
• DB modification, particularly with cerium, enhances ROS production, BMV formation, and DNA extraction efficiency.
• These findings highlight the potential of modified DBs for clinical applications in pathogen detection and DNA extraction.