Examining the Ability of Aerobic Halophilic Heterotrophic Microbial Consortia to Replace Ca by Mg in Different CaCO3 Precursors
Bibliographic record
Abstract
Recent laboratory experiments have exhibited microbes as promising agents in solving the perplexing origin of ancient dolomite by demonstrating microbial capability to mediate dolomite nucleation and growth. However, dolomite crystals from laboratory experiments have shown irrelevant characteristics to ancient dolomite from mineralogical and petrological perspectives. A major irrelevant characteristic is that ancient dolomite was assumed to be formed after the replacement of Ca by Mg in precursor CaCO 3 in a process known as diagenesis, which contrasts with the primary precipitation process observed in laboratory culturing experiments. Considering dolomite microbial experiments, one can imply the involvement of microbes in the formation of ancient dolomite, as microbes have shown the ability to overcome the dolomite kinetic barrier. Despite that fact, the ability of microbes in mediating dolomite diagenesis has not been investigated. In this study, microbes were applied to mediate replacement of Ca by Mg in different CaCO 3 precursors. The microbial replacement experiments were based on the enrichment of aerobic halophilic heterotrophic microbial consortia sampled from sediments collected from Al-Subiya sabkha in Kuwait. Two experiments were performed in saturated media at 35°C for 14 and 30 days simulating the conditions of microbial dolomite experiments. The change in mineralogy was examined via powder X-ray diffraction (XRD), and the change in texture and compositional microstructures was examined using scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). The effect of microbes on the alteration of CaCO 3 precursors was studied by comparing biotic experimentations with abiotic controls. The biotic samples were shown to result in the favorable conditions for dolomite formation including an increase in pH and alkalinity, but no changes were observed in mineralogy or compositional microstructure of CaCO 3 precursors. Our results suggest the inability of aerobic halophilic heterotrophic microbial consortia to introduce Mg replacement on CaCO 3 precursors in a timely manner that is comparable to primary precipitation in microbial dolomite experiments. The inability of the enriched microbial consortia to mediate replacement can be ascribed to different factors controlling the diagenetic process compared to primary precipitation in microbial dolomite experiments.
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 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 | 0.000 |
| 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 teacher head, 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".