Antibacterial Mechanism of Octamethylene-1,8-Bis(Dodecyldimethylammonium Bromide) Against E-coli

作者：Zhao Xiaofang^*; Li Yahong; Yuan Hao; Yin Jianhua; Hu Mingming

来源：Journal of Surfactants and Detergents, 2017, 20(3): 717-723.

DOI：10.1007/s11743-017-1942-z

• Cationic dimeric amphiphile
• Antibacterial mechanism
• Escherichia coli

The antibacterial activity of the cationic dimeric amphiphile octamethylene-1,8-bis(dodecyldimethylammonium bromide) (12-8-12) against the Gram-negative bacteria Escherichia coli was measured and compared with the monomeric amphiphile dodecyltrimethylammonium bromide (DTAB). The minimum inhibitory concentration (MIC) of 12-8-12 was about 1/20 of DTAB. By measuring the activity of beta-galactosidase and the image of field-emission scanning electron microscopy, it was revealed that the cationic amphiphile 12-8-12 interacted with the negatively charged membrane of E. coli and disrupted the membrane integrity, thus leading to the release of intracellular contents and the death of bacteria. To further explore the antibacterial mechanism, the interactions of cationic amphiphile 12-8-12 with biomacromolecules (bovine serum albumin (BSA) and salmon sperm DNA) were studied by measuring the intrinsic fluorescence of BSA and the zeta potential of DNA. It was shown that the antibacterial action site of cationic amphiphile was not only on the bacterial membrane but also on the intracellular contents such as protein and DNA.

• 出版日期2017-5
• 单位国家海洋局天津海水淡化与综合利用研究所