BACKGROUND: In this study the effects of the addition of emulsified polydimethylsiloxane (PMDS) FG-10 on the oxygen transfer coefficient (kLa) of submerged cultures of Staphylococcus warneri EX17 and its lipase production is described. FG-10 is an emulsified silicone capable of dissolving 50 times more oxygen than water. The combined effects of FG-10 concentration and different conditions of agitation were optimized in bioreactors using statistical design tools, and the cultures were run using raw glycerol from biodiesel synthesis as the sole carbon source. RESULTS: The optimal conditions found to improve lipase production were FG-10 concentration of 11.2% (v/v) and speed agitation of 527 rpm, respectively, producing around 861 U L-1 of lipolytic activity, a maximal cell concentration of 8.4 g L-1, and a kLa of 99 h-1, values that are approximately 3 times higher than cultures without FG-10. CONCLUSIONS: This is the first report in the literature on the use of this class of chemicals as oxygen carriers in microbial cultures and its effect on kLa and lipase production, demonstrating the potential use of FG-10 in microbial cultures. Copyright (c) 2012 Society of Chemical Industry