Related Experiment Video
Updated: Jun 4, 2025
08:58
Using Caenorhabditis elegans for Studying Trans- and Multi-Generational Effects of Toxicants
Published on: July 29, 2019
6.7K
Phenotypic Plasticity During Organofluorine Degradation Revealed by Adaptive Evolution
Madeline R O'Connor1, Calvin J Thoma1, Anthony G Dodge1
1Department of Biochemistry, Molecular Biology and Biophysics and Biotechnology Institute, University of Minnesota, Twin Cities, USA.
Microbial Biotechnology
|December 26, 2024
Summary
Engineered microbes adapted rapidly to fluoride stress from organofluorine biodegradation by reducing defluorinase gene copies and plasmid numbers. This adaptation minimizes toxicity, enhancing biodegradation efficiency.
Area of Science:
- Microbial Biotechnology
- Environmental Microbiology
- Biochemistry
Background:
- Fluoride anion toxicity from defluorinating enzymes limits organofluorine compound biodegradation.
- Engineered Pseudomonas putida strains expressing active defluorinases face challenges adapting to fluoride stress.
Purpose of the Study:
- To investigate the adaptive evolution of recombinant Pseudomonas putida to fluoride stress during organofluorine biodegradation.
- To understand the genetic and physiological mechanisms underlying microbial adaptation to fluoride toxicity.
Main Methods:
- Constitutive expression of two distinct defluorinases in Pseudomonas putida.
- Cultivation on α-fluorophenylacetic acid as the sole carbon source.
- Adaptive evolution via serial transfer and subsequent genomic sequencing.
Main Results:
- Both engineered strains rapidly adapted to fluoride stress, showing reduced lag times and increased growth yields within 50 generations.
- Genomic analysis revealed decreased defluorinase gene content and a 56%-57% reduction in plasmid copy number post-adaptation.
- The defluorinase activity was optimized for both pathway flux and minimizing fluoride toxicity, with evidence of gene deletion from plasmids.
Conclusions:
- Fluoride stress is a significant selective pressure during the biodegradation of organofluorine compounds.
- Engineered strains exhibit rapid adaptive responses, including alterations in gene copy number and plasmid composition, to mitigate fluoride toxicity.
- Microbial adaptation strategies are crucial for enhancing the efficiency of bioremediation for organofluorine pollutants.
Related Concept Videos
02:27Background and Environment Affect Phenotype
6.4K
Although the genetic makeup of an organism plays a major role in determining the phenotype, there are also several environmental factors, such as temperature, oxygen availability, presence of mutagens, that can alter an organism’s phenotype.
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
6.4K
01:21Frequency-dependent Selection
21.8K
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.
21.8K