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Quorum sensing-driven riboflavin-hyperproducing electroactive bacteria for enhanced bioelectricity generation from
Xin-Lu Cai1, Xuan Yao1, Xing-Yu Yang1
1Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China.
Synthetic and Systems Biotechnology
|July 19, 2026
Summary
Engineered bacteria boost bioelectricity from wastewater sludge. This synthetic biology approach enhances riboflavin production, significantly increasing power output and enabling sustainable resource recovery.
Area of Science:
- Bioelectrochemistry
- Synthetic Biology
- Microbial Engineering
Background:
- Waste activated sludge (WAS) is a byproduct of wastewater treatment and a source for bioenergy.
- Bioelectrochemical systems (BESs) convert WAS organic matter to electricity, but are limited by bacterial extracellular electron transfer (EET).
Purpose of the Study:
- To engineer a riboflavin-hyperproducing bacterial strain for enhanced BES performance.
- To develop a synthetic biology strategy for self-regulated microbial enhancements.
Main Methods:
- Designed a quorum sensing-driven synthetic circuit in *Shewanella oneidensis* to control riboflavin biosynthesis.
- Optimized gene expression through promoter tuning and codon optimization, creating the SQR2 strain.
- Evaluated SQR2 performance in bioreactors and hybrid BESs treating WAS.
Main Results:
- The SQR2 strain produced 269.9 mg/L riboflavin without affecting growth.
- BES performance improved significantly, with 22.2-fold higher current density and 11.6-fold higher power output.
- SQR2 enhanced electricity generation in WAS-treating BESs, reduced resistance, and promoted electroactive microbial communities.
Conclusions:
- A scalable, inducer-free synthetic biology strategy can enhance microbial EET capacity.
- This approach strengthens sludge-based bioelectricity generation.
- The engineered strain supports sustainable wastewater resource recovery through improved bioenergy production.
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