title: Separation and characterization of effective demulsifying substances from surface of Alcaligenes sp. S-XJ-1 and its application in water-in-kerosene emulsion.
abstract: The main goal of this work was to analyze the effect of surface substances on demulsifying capability of the demulsifying strain Alcaligenes sp. S-XJ-1. The demulsifying substances were successfully separated from the cell surface with dichloromethane-alkali treatment, and exhibited 67.5% of the demulsification ratio for water-in-kerosene emulsions at a dosage of 356mg/L. FT-IR, TLC and ESI-MS analysis confirmed the presence of a carbohydrate-protein-lipid complex in the demulsifying substances with the major molecular ions from mass-to-charge ratio (m/z) 165 to 814. After the substances separated, the cell morphology changed from aggregated to dispersed, and the concentration of cell surface functional groups decreased. Cell surface hydrophobicity and the ability of cell adhesion to hydrophobic surface of the treated cells was also reduced compared with original cell. It was proved that the demulsifying substances had a significant effect on cell surface properties and accordingly with demulsifying capability of Alcaligenes sp. S-XJ-1.
authors.affiliation: College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Ministry of Education Key Laboratory of Yangtze River Water Environment, Tongji University, Shanghai 200092, China.
authors.forename: Xiangfeng
authors.initials: X
authors.lastname: Huang
authors.forename: Kaiming
authors.initials: K
authors.lastname: Peng
authors.forename: Yi
authors.initials: Y
authors.lastname: Feng
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.forename: Lijun
authors.initials: L
authors.lastname: Lu
mesh_terms: D000421:Alcaligenes / Q000737:chemistry* / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development; D001422:Bacterial Adhesion / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D015169:Colony Count, Microbial; D045703:Emulsifying Agents / Q000302:isolation & purification*; D004655:Emulsions / Q000737:chemistry*; D007648:Kerosene / Q000032:analysis*; D013058:Mass Spectrometry; D011199:Potentiometry; D012972:Sodium Hydroxide / Q000494:pharmacology; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014867:Water / Q000737:chemistry*; D017155:Wettability / Q000187:drug effects
chemical_list: D045703:Emulsifying Agents; D004655:Emulsions; D007648:Kerosene; D012996:Solutions; D014867:Water; D012972:Sodium Hydroxide