Construction and Functional Characterization of a Heterologous Quorum Sensing Circuit in <i>Clostridium sporogenes</i>
Bibliographic record
Abstract
Quorum sensing (QS) is a bacterial communication mechanism that regulates gene expression in a population density-dependent manner. Substantial progress has been made in the engineering of QS systems in Gram-negative bacteria, but development of engineered QS systems in Gram positive bacteria remains limited. In this study, the obligate anaerobic Gram-positive bacterium Clostridium sporogenes was engineered with the Staphylococcus aureus agr-QS system to enable density-dependent gene regulation. Using LC-MS/MS, we confirmed production of autoinducing peptides in the engineered C. sporogenes strain. A QS-regulated GFP reporter demonstrated activation of expression in response to both exogenous AIP addition and increasing cell density, confirming functional integration of the agr operon. A media refreshment experiment showed that replacing the culture supernatant delayed QS activation, highlighting the importance of signal accumulation. Moreover, we observed that a noncognate AIP from another agr specificity group acts as a competitive antagonist, inhibiting gene expression under the QS promoter. To our knowledge, this study presents the first successful engineering of the agr quorum sensing system in an obligate anaerobe, expanding the synthetic biology toolkit and offering new opportunities for bacterial therapies and metabolic engineering.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".