FIG 1.

Overview of glycerol metabolism in Mycoplasma gallisepticum. Free glycerol is transported into the bacterial cell by the uptake facilitator GlpF. Glycerol is then phosphorylated by the glycerol kinase GlpK, producing glycerol-3-phosphate. Alternatively, if the UgpACE ABC transport system is functional in M. gallisepticum, it can take up and transport free glycerol-3-phosphate. Based on the work of others (6), we presume that the glycerol oxidase GlpO is a transmembrane enzyme that converts glycerol-3-phosphate to dihydroxyacetone phosphate (DHAP) and releases hydrogen peroxide as a by-product outside the bacterial cell.