Cells were centrifuged and resuspended in the production medium composed by (g L−1): crude glycerol 50; yeast extract 0.5; MgS04·H20 1.5; KH2PO4 6; Na2HPO4 0.5; CaCl2 0.75; FeCl3·6H2O 0.75; ZnSO4·7H2O 0.1;MnSO4·H20 0.3. Crude glycerol was provided by Prio Energy–Prio Biocombustíveis, SA and has the following composition (w/w): 90.4% glycerol, 9% water, 4.9% NaCl and less than 0.001% methanol and 0.5% of organic matter (non-glycerol).