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Updated: May 29, 2026

Temperature-Controlled Assembly and Characterization of a Droplet Interface Bilayer
Published on: April 19, 2021
Thermal regulation of membrane lipid fluidity by a two-component system in Bacillus subtilis
L M Bredeston1, D Marciano, D Albanesi
1Departamento de Química Biológica and IQUIFIB (UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, 1113 Buenos Aires, Argentina. bredes@qb.ffyb.uba.ar.
Abstract:
This article describes a simple and robust laboratory exercise on the regulation of membrane unsaturated fatty acid composition in bacteria by a decrease in growth temperature. We take advantage of the well characterized Des pathway of Bacillus subtilis, composed of a Δ5-desaturase (encoded by the des gene) and the canonical two-component system DesK-DesR, to study the transcriptional regulation of des during cold shock. Students analyze the expression of a reporter transcriptional fusion between the des promoter and the bacterial lacZ gene in a wild-type B. subtilis strain and in des or desK-desR mutants grown under different culture conditions. Measurements of β-galactosidase activity allow them to investigate how the Des pathway works and to assess the role of each component of this regulatory system.
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