Application of Yeast Hydrolysate in Extracellular Lipase Production by <i>Geotrichum candidum</i> in Shaken Flasks, Stirred Tank, and Airlift Reactors
Bibliographic record
Abstract
Lipase production by Geotrichum candidum NRRL Y‐552 was studied using an alternative nitrogen source, yeast hydrolysate (Prodex‐lac ® ), and soybean oil as the carbon source and inducer of lipase production. Factorial design and response surface methodologies were applied to obtain optimized conditions for lipase production in shaken flasks, defined as: 3.5 g/100 mL of yeast hydrolysate and 0.7 g/100 mL of soybean oil with an initial pH of 7.0 at 30 °C and 250 rpm. The resulting lipase activity after 48 h was 24.3 U/mL (0.506 U/mL . h), 52 % higher than with peptone under the same conditions (U = the amount of enzyme required to liberate 1 µmol of fatty acid per minute). Lipase production with the optimized medium was conducted in a stirred tank reactor and in an airlift bioreactor, both at 30 °C and 300 rpm; the best results obtained were 15.4 U/mL after 32 h of fermentation (0.481 U/mL.h) and 19.24 U/mL after 32 h of fermentation (0.601 U/mL . h) at 1 vvm, respectively. The results presented here from both bioreactors showed similar results to a previous study with the same microorganism under the same conditions using peptone as a nitrogen source. In addition, yeast hydrolysate is a cheaper nitrogen source than peptone and yeast extract, which permits a cost reduction above 90 % under similar conditions.
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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 | 0.000 | 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".