摘要
在实验室可控条件下,研究了生物表面活性剂鼠李糖脂对假单胞菌GP3A生长情况、降解芘(初始浓度为15mg·L-1)性能以及降解过程中菌体表面性质(细胞表面疏水性、菌体Zeta电位)的影响.结果表明,鼠李糖脂明显促进了GP3A的生长,当鼠李糖脂浓度为200mg·L-1和500mg·L-1时,72h时菌体的生长量比未加鼠李糖脂的体系分别增加了5倍和12倍.同时,鼠李糖脂的加入对芘的生物降解的促进作用随着鼠李糖脂浓度的升高而增大,未加鼠李糖脂的体系144h时芘的平均残留率为81%,而添加浓度为50、200和500mg·L-1鼠李糖脂的体系144h时芘的平均残留率分别下降为43%、39%和33%,降解率较未加鼠李糖脂的体系大幅提高.鼠李糖脂能引起菌体表面疏水性的明显增大,且低浓度鼠李糖脂(50mg·L-1)就能产生明显效果,50mg·L-1的鼠李糖脂体系中72h时细胞表面疏水性为66%,未加鼠李糖脂体系的细胞表面疏水性仅为21.1%,细胞表面疏水性的增大有利于底物的生物降解.鼠李糖脂可使菌体和含芘培养基的Zeta电位值的绝对值显著增大,但在鼠李糖脂存在的降解体系中,菌体和培养基的Zeta电位值并无显著改变.
This study aimed to investigate the effects of rhamnolipid on the growth of Pseudomonas sp. GP3A,its pyrene-degrading ablity（the initial pyrene concentration was 15 mg·L-1） and the cell surface properties including cell surface hydrophobicity and zeta potential of the strain during the degradation process. The results showed that rhamnolipid could obviously promote the growth of GP3A. Compared with the control grown in the absence of rhamnolipid,the biomass of GP3A increased 5 and 12 times in 72 h in 200 and 500 mg·L-1 rhamnolipid,respectively. In addition,the degradation of pyrene was accelerated with increasing rhamnolipid and the average residual rate of pyrene in 144 h decreased to 43%,39%,33%,respectively,for 50,200 and 500 mg·L-1 of rhamnolipid. The efficiency of pyrene removal was enhanced significantly over that without rhamnolipid,where the residual amount of pyrene was as high as 81%. The cell surface hydrophobicity was enhanced distinctly by rhamnolipid even at the 50 mg·L-1 low concentration. The cell surface hydrophobicity of GP3A cultivated in 50 mg·L-1 rhamnolipid reached 66% in 72 h,while that the control was only 21.1%. Increased cell surface hydrophobicity was beneficial to the degradation of the substrate. The absolute values of zeta potential of the bacteria and the culture medium with pyrene both increased with the addition of rhamnolipid. However,the addition of rhamnolipid had little effect on the zeta potential of the degradation system.
出处
《环境科学学报》
CAS
CSCD
北大核心
2011年第3期485-491,共7页
Acta Scientiae Circumstantiae
基金
广东省自然科学基金项目(No. 9351064101000001)
广东省科技计划项目(No. 2007A050100023)
广州市环保局科技成果应用示范项目~~
