Beyond SOx: Mining Sulfur Bacteria Produce Less Acid due to Unidentified Enzyme Pathways
Bibliographic record
Abstract
Abstract When thiosulfate is abundant, recent research indicates that the complete Sulfur Oxidation (cSOx) pathway is prevalent in oxic wastewater, while the incomplete Sulfur Oxidation and reverse Dissimilarity Sulfur Reduction (iSOx + rDSR) pathway has been found to be active under suboxic conditions, paired with nitrate reduction. However, both the activity of S 4 I (or other enzyme systems) and the suboxic sulfur reactions which occur when the rDSR pathway is not present in an SOB community remain unexplored. During this study, a series of 6 L benchtop microcosms were inoculated with Halothiobacillus spp. -dominated (containing cSOx and S 4 I pathways) sulfur oxidizing bacterial (SOB) communities preserved from an active tailing reservoir. The 16 microcosms were provided with high concentrations of the sulfur oxidation intermediate (SOI) compounds thiosulfate or tetrathionate under oxic and suboxic conditions to amplify the acid generating processes. The study identifies Halothiobacillus , Thiomonas, and Pandoraea , as the key SOB genera processing SOI. These microcosms demonstrate that protons yields resulting from thiosulfate oxidation by SOB are less than half of those predicted for thiosulfate oxidation, amongst the lowest reported for this genera. Despite adjustments for ion activity and PO 4 2- buffering, this difference is indicative of mechanisms beyond cSOx. Further, when offered tetrathionate under oxic conditions, undescribed reactions unmatched to known sulfur enzymes were likely employed, since disproportionation is insufficient to explain observations. Meanwhile, suboxic depletion of thiosulfate, without changes in nitrate or nitrite concentrations sufficient to indicate their use as TEA requires further investigation.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".