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Updated: Mar 31, 2026

Monitoring Intraspecies Competition in a Bacterial Cell Population by Cocultivation of Fluorescently Labelled Strains
Published on: January 18, 2014
A dual control mechanism synchronizes riboflavin and sulphur metabolism in Bacillus subtilis
Danielle Biscaro Pedrolli1, Christian Kühm2, Daniel C Sévin3
1Department of Biotechnology, Institute for Technical Microbiology, Hochschule Mannheim, 68163 Mannheim, Germany; Department of Bioprocess and Biotechnology, School of Pharmaceutical Sciences, Universidade Estadual Paulista (UNESP), 14801-902 Araraquara, Brazil;
Abstract:
Flavin mononucleotide (FMN) riboswitches are genetic elements, which in many bacteria control genes responsible for biosynthesis and/or transport of riboflavin (rib genes). Cytoplasmic riboflavin is rapidly and almost completely converted to FMN by flavokinases. When cytoplasmic levels of FMN are sufficient ("high levels"), FMN binding to FMN riboswitches leads to a reduction of rib gene expression. We report here that the protein RibR counteracts the FMN-induced "turn-off" activities of both FMN riboswitches in Bacillus subtilis, allowing rib gene expression even in the presence of high levels of FMN. The reason for this secondary metabolic control by RibR is to couple sulfur metabolism with riboflavin metabolism.
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