FIG. 9.

Model for quorum sensing in G. intermedius. The GinI/GinR quorum-sensing system in G. intermedius activates ginA expression, which in turn represses oxidative fermentation, including acetic acid and gluconic acid fermentation, and growth in the presence of ethanol. The GinA protein also represses the antifoam activity of the cells. Other target genes of GinR may be present that also affect these phenotypes. These target genes are expected to have a negative effect on oxidative fermentation and growth in the presence of ethanol and a positive effect on antifoam activity.