Medium Optimization for the Production of Phytase by Recombinant Pichia pastoris Grown on Glycerol
Bibliographic record
Abstract
Based on statistical designs, minimal salts medium, commonly used for yeast cultivation, was optimized to maximize GAP promoter-mediated phytase production by recombinant Pichia pastoris grown on glycerol. A Plackett-Burman design was followed to screen medium components to determine those that significantly affected phytase production. Of the 8 components studied, the concentrations of K2SO4, CaSO4•2H2O and MgSO4•7H2O were identified as having a significant effect. These three components were subsequently optimized by response surface methodology using a central composite design. The optimal concentrations of the three components, leading to a maximal extracellular phytase activity of 161.64 U/ml, were K2SO4 13.25g/l, CaSO4•2H2O 1.03g/l and MgSO4•7H2O 17.94g/l. The activity measured in cultures using optimized growth medium is significantly higher than the 73.31 U/ml measured in cultures using standard minimal salts media. The theoretical phytase yields predicted by the developed model were very close to experimentally obtained values.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| 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".