Multi-focused laboratory experiments based on Quorum Sensing and Quorum Quenching for acquiring Microbial Physiology concepts

TORRES MARIELA ANALÍA; ALEJANDRA LEONOR VALDEZ; CAROLINA DE LOURDES OLEA; MARÍA FERNANDA FIGUEROA; CARLOS G. NIETO PEÑALVER

Biochemistry and Molecular Biology Education

John Wiley and Sons Inc

Año: 2024

After a time away from the classrooms and laboratories due to the global pandemic,the return to teaching activities during the semester represented a challengeto both teachers and students. Our particular situation in a MicrobialPhysiology course was the necessity of imparting in shorter time, laboratorypractices that usually take longer. This article describes a 2-week-long laboratoryexercise that covers several concepts in an interrelated way: conjugationas a gene transfer mechanism, regulation of microbial physiology, productionof secondary metabolites, degradation of macromolecules, and biofilm formation.Utilizing a Quorum Quenching (QQ) strategy, the Quorum Sensing(QS) system of Pseudomonas aeruginosa is first attenuated. Then, phenotypesregulated by QS are evidenced. QS is a regulatory mechanism of microbialphysiology that relies on signal molecules. QS is related in P. aeruginosa to severalvirulence factors, some of which are exploited in the laboratory practicespresented in this work. QQ is a phenomenon by which QS is interrupted orattenuated. We utilized a QQ approach based on the enzymatic degradation ofthe P. aeruginosa QS signals to evidence QS-regulated traits that are relevant toour Microbial Physiology course. Results obtained with the same test performedby a random group of students before and after the activities show thepositive effectiveness of the approach presented in this work.