Characterization and mapping of the Bacillus subtilis prtR gene

Area of Science:

• Microbiology
• Molecular Biology
• Biochemistry

Background:

• Bacillus subtilis is a key industrial microorganism.
• Enzyme production in B. subtilis can be enhanced through genetic manipulation.
• A previously described gene from Bacillus natto was known to enhance protease and levansucrase production.

Purpose of the Study:

• To investigate the function of a gene enhancing enzyme production in Bacillus subtilis.
• To characterize the genetic locus of this enzyme-enhancing gene.
• To determine the necessity of this gene for normal Bacillus subtilis growth and function.

Main Methods:

• Gene isolation from Bacillus natto and Bacillus subtilis.
• Cloning the gene onto a high-copy plasmid for overexpression in B. subtilis.
• Genetic mapping to determine the gene's chromosomal location.
• Gene deletion to assess its role in the native B. subtilis chromosome.

Main Results:

• An identical gene was found in both B. natto and B. subtilis.
• Overexpression of the gene on a high-copy plasmid significantly enhanced alkaline protease, neutral protease, and levansucrase production in B. subtilis.
• Genetic mapping placed the gene near metB, distinct from other known pleiotropic genes.
• Deletion of the gene from the B. subtilis chromosome resulted in no discernible phenotypic changes.

Conclusions:

• The identified gene plays a role in enhancing the production of specific extracellular enzymes in Bacillus subtilis when overexpressed.
• The gene's function appears to be related to enzyme regulation rather than essential metabolic processes, as its deletion had no phenotypic consequence.
• This gene represents a potential target for metabolic engineering to improve industrial enzyme yields from B. subtilis.