Molecular Investigation of Chloroethene Reductive Dehalogenation by the Mixed Microbial Community KB1
Bibliographic record
Abstract
Bioaugmentation with Dehalococcoides-containing cultures is a successful technology for the remediation of chlorinated ethene-contaminated roundwater. The overall goal of this research was to identify and characterize genes that are used by a Dehalococcoides-containing culture, KB-1, during degradation of Trichloroethene (TCE) to ethene, via cis-Dichloroethene (cDCE) and vinyl chloride. Firstly, the diversity and dynamics of the microbial populations within KB1 was assessed using 16S rRNA clone libraries and quantitative PCR analyses. Secondly, \nreductive-dehalogenase-homologous- (RDH) genes in KB1 were identified, sequenced and their transcription compared through RNA-generated RDH cDNA clone libraries. Finally, to elucidate functionally important genes within the community, Shotgun metagenome microarrays were constructed and used to investigate transcription during dechlorination. \nResults of the phylogenetic analyses indicated that KB1 is a diverse community of \nmicroorganisms whose stability is enhanced by functional redundancy within the culture. To fully understand this diverse community of uncultivated microorganisms a metatranscriptome approach was used. Experiments with shotgun metagenome microarrays identified spots which were statistically significantly differentially expressed during dechlorination. These spots were then sequenced, revealing Dehalococcoides and non-Dehalococcoides-genes which are important during dechlorination. These results demonstrated that shotgun microarrays can be constructed without prior sequence knowledge and used to effectively examine differential \ntranscription within an uncultivated community. Subsequently, all of the spots of the array were sequenced, and additional array experiments were conducted. Sequencing identified 24 reductive dehalogenase genes in the culture, and analysis of the microarray results indicated that many of these RDH genes were differentially expressed in response to certain chlorinated compounds. Interspecies interactions were also highlighted as results suggested that non-\nDehalococcoides microorganisms provide partial corrinoids which Dehalococcoides salvages to synthesize cobalamin which is essential for reductive dehalogenation. Transcription of CRISPR-associated genes also indicated interaction between phage and other microorganism in the KB1 community. Overall these results provided sequence and transcription information about possible biomarkers for reductive dechlorination by KB1 and can be used for more effective \ndesign and monitoring of bioremediation technologies.
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 | 0.000 | 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".