Bioaugmentation of Activated Sludge with Two<i>Pseudomonas putida</i>Strains for the Degradation of 4-Chlorophenol
Bibliographic record
Abstract
The augmentation of activated sludge with two strains of Pseudomonas putida, CP1 and A(a) was investigated. Both strains of bacteria degraded 1.56 mM 4-chlorophenol. P. putida CP1 degraded the chemical using a modified ortho-cleavage pathway while P. putida A(a) used the meta-cleavage pathway. When activated sludge incapable of 4-chlorophenol degradation was augmented with either strain, substrate degradation occurred and followed the same biochemical pathways as when the bacteria were grown in pure culture. Insertion, in tandem, of the genes for gentamycin resistance and green fluorescent protein into the chromosomes of the two strains, enabled the survival and spatial location of the bacteria in the mixed microbial population to be monitored. Labelling the bacteria did not alter their degradative capabilities. P. putida CP1::Tn7-gfp survived in higher numbers than P. putida A(a)::Tn7-gfp following addition to the activated sludge. This was attributed to the ability of this strain to flocculate and become integrated in the activated sludge floc. Addition of P. putida CP1::Tn7-gfp or A(a)::Tn7-gfp to activated sludge resulted in smaller decreases in total cell numbers indicating a protective effect of the introduced P. putida strains on the overall microbial population from the harmful effects of 4-chlorophenol. The non-flocculant strain A(a) did not survive as well as CP1 in the activated sludge system and required a higher inoculum size to effect substrate degradation.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 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".