title: [Production of biodemulsifier by Alcaligenes sp. S-XJ-1 using waste diesel oil].
abstract: Biodemulsifier is a new type of demulsifiers for breaking oil-water emulsion. One demulsifier-producing strain, Alcaligenes sp. S-XJ-1 could grow on waste diesel oil (WDO), dry weight of the strain was up to 2.0 g/L after being cultivated for 7 d, 10 g/L S-XJ-1 cell suspension reduced surface tension of water from 72.0 mN/m to 29.7 mN/m. Biodemulsifier produced by S-XJ-1 was 0.3 g/L, its critical micelle concentration (CMC) was 150 mg/L, showing a better surface activity than chemical surfactant SDS. Furthermore, it showed an demulsifying efficiency over 70% for W/O model emulsion. It was indicated S-XJ-1 could utilize C14-C20 n-alkanes composing waste diesel oil by GC-MS, C20 n-alkane was almost completely comsumed by S-XJ-1 with utilization ratio of 99%. In addition, n-alkanes utilization ratio and demulsifying capability increased when length of carbon chain increased. Both utilization ratio and demulsifying capability of biodemulsifier produced by S-XJ-1 using C20 n-alkane as the carbon source were superior to other n-alkanes, and similar to waste diesel oil. It was identified the biodemulsifier produced by S-XJ-1 using waste diesel oil was lipopeptide by TLC and FTIR.
authors.affiliation: College of Resource and Environment, Northwest Sci-Tech University of Agriculture and Forestry, Yangling 712100, China. biduoduoduo@sina.com
authors.forename: Na
authors.initials: N
authors.lastname: Yang
authors.forename: Gui-Ying
authors.initials: GY
authors.lastname: Feng
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Lu
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.forename: Xiang-Feng
authors.initials: XF
authors.lastname: Huang
mesh_terms: D000421:Alcaligenes / Q000378:metabolism*; D001673:Biodegradation, Environmental; D045703:Emulsifying Agents / Q000737:chemistry*; D004655:Emulsions / Q000737:chemistry; D005227:Fatty Acids / Q000378:metabolism; D005742:Gasoline; D055666:Lipopeptides / Q000378:metabolism; D013501:Surface-Active Agents / Q000737:chemistry; D014866:Waste Products / Q000032:analysis*
chemical_list: D045703:Emulsifying Agents; D004655:Emulsions; D005227:Fatty Acids; D005742:Gasoline; D055666:Lipopeptides; D013501:Surface-Active Agents; D014866:Waste Products