Conversion of glycerol 3-phosphate to dihydroxyacetone. Uses molecular oxygen or nitrate as electron acceptor. a quinone + sn-glycerol 3-phosphate = a quinol + dihydroxyacetone phosphate Polyol metabolism; glycerol degradation via glycerol kinase pathway; glycerone phosphate from sn-glycerol 3-phosphate (aerobic route): step 1/1. There are two sn-glycerol-3-phosphate dehydrogenase isozymes in E.coli: one is aerobic, the other anaerobic. Belongs to the FAD-dependent glycerol-3-phosphate dehydrogenase family.