Electron acceptor redox potential globally regulates transcriptomic profiling in Shewanella decolorationis S12

Area of Science:

• Microbial Physiology
• Environmental Microbiology
• Bioelectrochemistry

Background:

• Electron acceptor redox potential (EARP) is crucial for microbial metabolism in natural and engineered systems.
• Limited understanding exists regarding the global impact of EARP on bacterial physiology.

Purpose of the Study:

• To investigate the physiological and transcriptomic responses of Shewanella decolorationis S12 to varying EARPs.
• To elucidate the role of EARP as a determinant of microbial metabolic pathways.

Main Methods:

• Utilized microbial electrochemical systems to control EARP and isolate its effects.
• Compared physiological and transcriptomic profiles of S12 under different EARPs (0.8 V, 0.2 V, -0.2 V).

Main Results:

• Metabolic activity showed a non-linear response to EARP.
• Tricarboxylic acid cycle was downregulated, while the glyoxylate shunt was upregulated at high EARP (0.8 V).
• Flagella assembly and sulfur metabolism pathways were enriched at high EARP, suggesting enhanced electrokinesis and oxidative stress response.

Conclusions:

• EARP is a significant, but not sole, determinant of microbial metabolic pathways.
• High EARP induces distinct physiological adaptations in S12, including altered central carbon metabolism and stress responses.
• Findings provide novel insights into global EARP regulation of microbial metabolism.