A simple and sensitive biosensor strain for detecting toxoflavin using β-galactosidase activity.

Area of Science:

• Microbiology
• Biotechnology
• Environmental Science

Background:

• Toxoflavin is a potent toxin produced by Burkholderia glumae, causing significant agricultural damage.
• Toxoflavin acts as a co-activator for the LysR-type transcriptional regulator ToxR, essential for its own biosynthesis.
• Existing methods for toxoflavin detection can be complex and costly.

Purpose of the Study:

• To develop a simple, sensitive, and cost-effective biosensor for toxoflavin determination.
• To create a novel biosensor strain for identifying toxoflavin-producing bacteria and contaminated samples.
• To establish a reliable method for quantifying toxoflavin in natural samples.

Main Methods:

• Constructed a novel biosensor strain (COK71) of Burkholderia glumae by integrating the lacZ reporter gene into the toxoflavin biosynthesis operon (toxABCDE).
• Utilized β-galactosidase activity, measured via substrates like X-gal or ONPG, to indicate toxoflavin presence and concentration.
• Employed a simple assay involving the sensor strain, substrates, and culture medium without complex sample preparation.

Main Results:

• The biosensor demonstrated high specificity for toxoflavin.
• The method allowed for the quantification of toxoflavin in the range of 50-500 nM.
• The biosensor successfully identified toxoflavin-producing bacteria in real-world samples.
• The biosensor strain showed excellent performance for diagnostic applications.

Conclusions:

• A novel and efficient biosensor for toxoflavin detection has been successfully developed.
• The biosensor offers a simple, cost-effective, and reliable tool for identifying toxoflavin-producing bacteria and contaminated food or environmental samples.
• This biosensor has significant potential for diagnostic applications in agriculture and food safety.