Characterization of the extracellular biodemulsifier of Bacillus mojavensis XH1 and the enhancement of demulsifying efficiency by optimization of the production medium composition

► Biodemulsifier identified as a protein and a lipopeptide in Bacillus mojavensis XH1. ► Biodemulsifier efficiency and yield enhanced by glucose and liquid paraffin. ► Biodemulsifier products inhibited by absence of yeast extract, phosphate or NH4Cl. ► Demulsifying ability improved via optimizing media by response surface methodology.