Related Experiment Video
Updated: Apr 2, 2026
A Loop-mediated Isothermal Amplification LAMP Assay for Rapid Identification of Bemisia tabaci
Published on: October 29, 2018
Identification, sequencing and comparative analysis of pBp15.S plasmid from the newly described entomopathogen
Diana C Garcia-Ramon1, Maria Jose Luque-Navas1, C Alfonso Molina2
1Institute of Biotechnology, Campus Fuentenueva s/n, University of Granada, 18071 Granada, Spain.
Abstract:
The Bacillus pumilus 15.1 strain, a recently described entomopathogenic strain active against Ceratitis capitata, contains at least two extrachromosomal elements, pBp15.1S and pBp15.1B. Given that B. pumilus is not a typical entomopathogenic bacterium, the acquisition of this extrachromosomal DNA may explain why B. pumilus 15.1 is toxic to an insect. One of the plasmids present in the strain, the pBp15.1S plasmid, was sub-cloned, sequenced and analyzed using bioinformatics to identify any potential virulence factor. The pBp15.1S plasmid was found to be 7785 bp in size with a GC content of 35.7% and 11 putative ORFs. A replication module typical of a small rolling circle plasmid and a sensing and regulatory system specific for plasmids was found in pBp15.1S. Additionally, we demonstrated the existence of ssDNA in plasmid preparations suggesting that pBp15.1S replicates by the small rolling circle mechanism. A gene cluster present in plasmid pPZZ84 from a distantly isolated B. pumilus strain was also present in pBp15.1S. The plasmid copy number of pBp15.1S in exponentially growing B. pumilus cells was determined to be 33 copies per chromosome. After an extensive plasmid characterization, no known virulence factor was found so a search in the other extrachromosomal elements of the bacteria is needed.
Insights
Bacillus pumilus 15.1, an insect-toxic bacterium, harbors extrachromosomal DNA. Analysis of the pBp15.1S plasmid revealed no known virulence factors, suggesting further investigation into other genetic elements is necessary.
Area of Science:
- Microbiology
- Genetics
- Insect Pathology
Background:
- Bacillus pumilus is not typically entomopathogenic.
- The strain B. pumilus 15.1 exhibits insecticidal activity against Ceratitis capitata.
- Extrachromosomal elements may confer insecticidal properties.
Purpose of the Study:
- To characterize the pBp15.1S plasmid from B. pumilus 15.1.
- To identify potential virulence factors within the pBp15.1S plasmid.
- To understand the genetic basis of entomopathogenicity in B. pumilus 15.1.
Main Methods:
- Sub-cloning and sequencing of the pBp15.1S plasmid.
- Bioinformatic analysis of plasmid DNA.
- Determination of plasmid copy number and replication mechanism.
Main Results:
- The pBp15.1S plasmid is 7785 bp with 11 putative ORFs and 35.7% GC content.
- A small rolling circle replication module and a plasmid-specific regulatory system were identified.
- Single-stranded DNA (ssDNA) presence confirmed the rolling circle replication mechanism.
- A gene cluster found in another B. pumilus plasmid was also present.
- Plasmid copy number was determined to be 33 copies per chromosome.
Conclusions:
- The pBp15.1S plasmid possesses typical features of a small rolling circle plasmid.
- No known virulence factors were identified on the pBp15.1S plasmid.
- Further research on other extrachromosomal elements is required to explain the entomopathogenicity of B. pumilus 15.1.
More Related Videos
06:58Author Spotlight: Evaluation of Entomopathogenic Fungi in Wild Monochamus alternatus Populations for Biocontrol Applications in Forest Wood Borers
Published on: September 29, 2023
12:23Recombinant Protein Expression, Crystallization, and Biophysical Studies of a Bacillus-conserved Nucleotide Pyrophosphorylase, BcMazG
Published on: May 16, 2017
