Occurrence of several genes encoding putative reductive dehalogenases in<i>Desulfitobacterium hafniense/frappieri</i>and<i>Dehalococcoides ethenogenes</i>
Bibliographic record
Abstract
Desulfitobacterium frappieri PCP-1 has the capacity to dehalogenate several halogenated aromatic compounds by reductive dehalogenation, however, the genes encoding the enzymes involved in such processes have not yet been identified. Using a degenerate oligonucleotide corresponding to a conserved sequence of CprA/PceA reductive dehalogenases, a cprA-like gene fragment was amplified by PCR from this bacterial strain. A Desulfitobacterium frappieri PCP-1 cosmid library was screened with the PCR product, allowing the cloning and sequencing of a 1.9-kb fragment. This fragment contains a nucleic acid sequence identical to one genomic contig of Desulfitobacterium hafniense, a bacterium closely related to Desulfitobacterium frappieri that is also involved in reductive dehalogenation. Other genes related to the Desulfitobacterium dehalogenans cpr locus were identified in this contig. Interestingly, the gene arrangement shows the presence of two copies of cprA-, cprB-, cprC-, cprD-, cprK-, and cprT-related genes, suggesting that gene duplication occurred within this chromosomic region. The screening of Delfitobacterium hafniense genomic contigs with a CprA-deduced amino acid sequence revealed two other cprA-like genes. Microbial genomes available in gene databases were also analyzed for sequences related to CprA/PceA. Two open reading frames encoding other putative reductive dehalogenases in Desulfitobacterium hafniense contigs were detected, along with 17 in the Dehalococcoides ethenogenes genome, a bacterium involved in the reductive dehalogenation of tetrachloroethene to ethene. The fact that several gene encoding putative reductive dehalogenases exist in Delfitobacterium hafniense, probably in other members of the genus Desulfitobacterium, and in Dehalococcoides ethenogenes suggests that these bacteria use distinct but related enzymes to achieve the dehalogenation of several chlorinated compounds [corrected].
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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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 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".