Characterization of biosynthetic and catabolic pathways of Bacillus subtilis strain 168.

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Amy L. Quattlebaum (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:
Jason Reddick

Abstract: Bacillus subtilis has long been a model bacterium for understanding biological mechanisms, such as fatty acid catabolism and polyketide biosynthesis. Our interest in the latter was centered on the polyketide synthase (PKS) mechanism responsible for ß-branching polyketides. The unique structural moiety is attributed to a HMG-CoA synthase homolog, such as the pksG gene in B. subtilis. The first goal was a metagenomic survey of local soils, using the conserved pksG homolog sequence as a genetic marker. After optimizing techniques for the extraction and purification of environmental DNA, the ß-branching polyketide population was not detected in any local soil samples. While working with a pksG homolog, an apparent sequence anomaly prompted us to verify the taxonomic classification of B. subtilis research strains ATCC 39374 and 39320. Comparison of DNA sequences (pksG homologs, hypervariable regions of 16S rRNA and rDNA) and species-specific genes showed the two ATCC strains are more closely related to B. amyloliquefaciens. A group of genes named the mmg operon, able to catalyze fatty acid catabolism, are active only during B. subtilis sporulation. Our hypothesis was that, by creating a conditional genetic knockout mutation, the bacterium would be capable of in-vitro growth in propionate media. Attempts to subclone portions of mmg DNA were unsuccessful. However, the neighboring YqiQ protein was successfully isolated and purified.

Additional Information

Language: English
Date: 2009
Bacillus subtilis, Metabolism, Polyketides, Synthesis,
Bacillus subtilis $x Research.
Polyketides $x Synthesis.

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