Alcaligenes sp.S-XJ-1利用废弃柴油合成生物破乳剂的研究

Production of Biodemulsifier by Alcaligenes sp. S-XJ-1 Using Waste Diesel Oil

生物破乳剂是一种用于油水分离的新型破乳剂.采用废弃柴油培养生物破乳剂产生菌Alcaligenes sp.S-XJ-1,培养7 d,菌株干重最高可达2.0 g/L,10 g/L的菌株细胞悬液能够将水表面张力从72.0 mN/m降低到29.7 mN/m.生物破乳剂产量为0.3 g/L,其CMC为150 mg/L,表面活性优于化学表面活性剂SDS,且对W/O模型乳状液的破乳效果在70%以上.废弃柴油GC-MS测试结果表明,S-XJ-1菌株能够利用废弃柴油中的C14～C20正构烷烃,且C20正构烷烃几乎被完全利用,其利用率高达99%.S-XJ-1菌株对不同碳链长度正构烷烃复配碳源的利用率及破乳性能随着碳链长度的延长而逐渐增加.与其他正构烷烃复配碳源相比,S-XJ-1菌株对C20正构烷烃利用率最高,合成破乳剂的性能最好,且与废弃柴油研究结果最为接近.TLC和FTIR分析表明S-XJ-1菌株利用废弃柴油合成的生物破乳剂为脂肽类物质.

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.