Screening, Identification of Strain JM-1 Producing Biodemulsifier and the Characteristic of Demulsification

A strain JM-1 producing biodemulsifier with high efficiency was isolated from cold rolling plant emulsion wastewater untreated. The experimental results proved that demulsification rate of JM-1 culture broth achieved 97.1%, oil removal rate 97.38% with 8 h in room temperature. The strain JM-1 was identified as Candida tropicalis based on physiological and biochemical characteristics, 26SrDNA sequence homology analysis, and phylogeny tree constructed. Comparing with the demulsification activity of culture broth, supernatant, cells, and blank medium, it was proved that the biosurfactant generated by JM-1 in organism metabolism was the main active biodemulsification component.