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

After a time away from the classrooms and laboratories due to the global pandemic, the return to teaching activities during the semester represented a challenge to both teachers and students. Our particular situation in a Microbial Physiology course was the necessity of imparting in shorter time, laboratory practices that usually take longer. This article describes a 2-week-long laboratory exercise that covers several concepts in an interrelated way: conjugation as a gene transfer mechanism, regulation of microbial physiology, production of secondary metabolites, degradation of macromolecules, and biofilm formation.

Vinasse as a substrate for inoculant culture and soil fertigation: Advancing the circular and green economy.

Vinasse is a by-product with a key role in circular economy. In this work, we analyze sugarcane vinasse as culture medium for obtaining single and mixed inoculants. Trichoderma harzianum MT2 was cultured in single and sequential co-culture with Pseudomonas capeferrum WCS358 or Rhizobium sp.

Modulation of quorum sensing activity by copper sulfate, potassium dichromate, and cadmium chloride in biosensor strains.

Beyond their biological roles, metals have a strong impact on the environment. It has been reported that metals are also inhibitory of Quorum Sensing (QS) mechanisms, ones of the best characterized signaling systems in bacteria and fungi. We analyzed the effect of CuSO4, CdCl2, and K2Cr2O7, on QS systems sharing or differing in the bacterial host or the QS signal.

Insight in the quorum sensing-driven lifestyle of the non-pathogenic Agrobacterium tumefaciens 6N2 and the interactions with the yeast Meyerozyma guilliermondii.

Agrobacterium tumefaciens is considered a prominent phytopathogen, though most isolates are nonpathogenic. Agrobacteria can inhabit plant tissues interacting with other microorganisms. Yeasts are likewise part of these communities.

Blue light directly modulates the quorum network in the human pathogen Acinetobacter baumannii.

Quorum sensing modulates bacterial collective behaviors including biofilm formation, motility and virulence in the important human pathogen Acinetobacter baumannii. Disruption of quorum sensing has emerged as a promising strategy with important therapeutic potential. In this work, we show that light modulates the production of acyl-homoserine lactones (AHLs), which were produced in higher levels in the dark than under blue light at environmental temperatures, a response that depends on the AHL synthase, AbaI, and on the photoreceptor BlsA.