Phenotypic and physiological changes in Acinetobacter sp. strain DR1 with exogenous plasmid
1Division of Environmental Science and Ecological Engineering, Korea University, Anam-Dong 5 Ga, 136-713, Seoul, South Korea.
Current Microbiology
|July 8, 2010
Summary
This study shows that genetic manipulation of diesel-degrading Acinetobacter sp. strain DR1 using plasmid pRK415 altered its motility, biofilm formation, and stress responses. Researchers advise caution during plasmid-mediated genetic modification due to potential host changes.
Area of Science:
- Microbiology
- Environmental Science
- Genetics
Background:
- The genus Acinetobacter is known for its ability to acquire exogenous DNA from the environment.
- Natural transformation is a key mechanism for genetic exchange in bacteria.
- Understanding genetic manipulation in environmental bacteria like Acinetobacter is crucial for biotechnology applications.
Purpose of the Study:
- To investigate the natural transformation efficiency of a novel diesel-degrading Acinetobacter sp. strain (DR1) using the broad-host-range plasmid pRK415.
- To characterize phenotypic and physiological changes in Acinetobacter sp. strain DR1 following successful natural transformation.
- To assess the impact of plasmid uptake on bacterial traits such as motility, biofilm formation, and oxidative stress resistance.
Main Methods:
- Natural transformation experiments were performed using Acinetobacter sp. strain DR1 and the plasmid pRK415.
- Optimization of transformation efficiency was explored by varying factors like temperature, DNA concentration, and aeration.
- Phenotypic and physiological assessments included evaluating motility, biofilm formation, and sensitivity to oxidative stress agents (hydrogen peroxide, cumene hydroperoxide).
Main Results:
- Successful natural transformation of Acinetobacter sp. strain DR1 with plasmid pRK415 was achieved.
- Transformed cells exhibited significant alterations compared to the wild-type strain.
- Key changes included reduced motility, attenuated biofilm formation, and increased sensitivity to hydrogen peroxide and cumene hydroperoxide.
Conclusions:
- Natural transformation with plasmid pRK415 significantly impacts the phenotype and physiology of Acinetobacter sp. strain DR1.
- Genetic manipulation via plasmids can lead to unintended alterations in bacterial traits.
- Caution is advised when performing genetic modifications with plasmids due to potential host-associated changes.
Related Concept Videos
01:33Bacterial Transformation
In 1928, bacteriologist Frederick Griffith worked on a vaccine for pneumonia, which is caused by Streptococcus pneumoniae bacteria. Griffith studied two pneumonia strains in mice: one pathogenic and one non-pathogenic. Only the pathogenic strain killed host mice.Griffith made an unexpected discovery when he killed the pathogenic strain and mixed its remains with the live, non-pathogenic strain. Not only did the mixture kill host mice, but it also contained living pathogenic bacteria that...
00:57Antibiotic Selection
Overview
01:28Plasmids
Plasmids are extrachromosomal DNA molecules found in bacteria, archaea, and some eukaryotic microbes like yeast. These small, circular DNA structures typically contain fewer than 30 genes, although some may exist linearly. Plasmids vary in their number within a cell, known as copy number. Single-copy plasmids are present in one copy per cell and multi-copy plasmids are present in multiple copies, reaching over 100 copies per cell.Plasmids usually replicate independently of the chromosomal DNA...