Dietzia sp.S-JS-1利用煎炸废油生产生物破乳剂及其性能研究

以前期研究中筛选得到的破乳剂产生菌Dietzia sp.S-JS-1为研究对象,采用煎炸废油为培养碳源,考察菌株的生物量和表面张力,研究处理方式、温度、乳状液pH对破乳剂在两种模型乳状液W/O型(water in oil)和O/W型(oilin water)中破乳性能的影响,并初步分析生物破乳剂成分。结果表明:菌株最大生物量为2.6 g/L,其产生的破乳剂能够将纯水表面张力从72.0 mN/m降低到32.5 mN/m。冻融对破乳剂效果的影响小于高温灭菌;破乳剂经冷冻干燥处理后的破乳效果明显好于烘干处理;破乳剂在35℃～75℃时具有较好的破乳效果,脱水率均在75%以上;破乳剂在W/O型乳状液中的效果随着pH变大而逐渐增加,pH=10时的脱水率高达99.8%,而在O/W型乳状液中,pH=7时的脱水率最高,为90%左右。薄层色谱结果表明S-JS-1利用煎炸油生产的生物破乳剂可能含有5种脂肽类物质。

Properties of bio-demulsifiers produced by Dietzia sp. S-JS-1 using wasted frying oils

A strain producing bio-demulsifiers of Dietzia sp. previously isolated from the soils contaminated by crude oils was named S-JS-1. Cultivated characteristics using WFO, influences of treatment methods, pH and temperature on demulsification in two model emulsions were investigated. The results showed that the maximum dry biomass was 2.6 g/L with WFO as the single carbon source, the bio-demulsifiers produced by S-JS-1 showed high surface activity lowering the surface tension of water from 72.0 mN/m to 32.5 mN/m. Influence of freeze-thawing on demulsification was smaller than sterilization, effect of freeze-drying treatment on demulsification was significantly better than drying treatment. Water breaking ratio of emulsions was 75% obtained by bio-demulsifiers during 35℃ to 75℃. Water breaking ratio of W/O emulsion primarily increased and then decreased since the pH increased, and finally reached 99.8% when pH equaled to 10, the optimal water breaking ratio of O/W emulsion was obtained approximately 90% when pH was equal to 7. In addition, thin-layer chromatography revealed that the bio-demulsifiers comprised five different lipopeptides.