本文通过生物降解和摩擦学试验研究了脂肪酰基胱氨酸对石蜡矿物润滑油生物降解和摩擦学性能的影响,通过观察石蜡油降解过程中微生物菌体形态变化分析了添加剂促进润滑油生物降解的机理.结果表明:脂肪酰基胱氨酸能显著地提高石蜡基础油的生物降解性能,有效提高基础油的承载能力和减摩抗磨性能.试验菌种B1502在不含添加剂的石蜡油培养液中12 h即有芽孢形成,48 h菌体全部转变为芽孢;在含添加剂的石蜡油培养液中,试验菌种168 h始终保持营养体的形态,未观察到芽孢形成.添加剂促进石蜡油生物降解的作用机理是为降解润滑油的微生物提供前期生长所需的营养成分以维持其旺盛的生长状态,使中后期石蜡油分解代谢相关酶的表达水平或活性增加,起到促进石蜡油生物降解的作用.
Impacts of fatty acyl cystine on the biodegradability and tribological performances of mineral lubrication oil were investigated based on the biodegradation and tribological experiments,the mechanism for additive to promote the biodegradability of lubricant was also discussed by the observation on morphous change of bacteria in the process of paraffin oil degradation.The results showed that fatty acyl cystines significantly improved the biodegradability of paraffinic base oil,and exhibited good load-carrying capacity,friction reduction and antiwear properties.The B1502 bacteria started to form spores after 12 h,and all the bacteria transformed into spores after 48 h while growing in the medium with paraffin oil as unique carbon source.However,the bacteria might still maintain the morphous of trophozoite and few spores was observed in the test period of 168 h while fatty acyl amino acid was added into the same medium.The mechanism for additive promoting the biodegradability of lubricant was that fatty acyl amino acid could furnish enough nutrient content for degradation bacteria in the initial stage,which might keep the bacteria growing vigorously,and improve the expression level or activity of enzymes related to degradation of paraffin oil,which resulted in the enhancement of biodegradability of paraffin lubricating oil.