The sorption of anthraquinone dye into E. coli bacteria and the dye impact on the bacteria viability

Abstract

For translocation across the cell envelope of Gram-negative bacteria, substances have to overcome two permeability barriers, the inner and outer membrane. However, the material trapped inside the cell can be discarded pumps. Escherichia coli AcrAB system is a Multi-exhaust system made of RND-type transporter AcrB and periplasmic AcrA additional protein, which is directly emitted into the environment and a variety of soluble fatty amphiphilic inhibitor [1]. Understanding the mechanism of the different export apparatus could help to develop new drugs, which block the efflux pumps [2]. Investigations were carried out with the newly synthesized anthraquinone dyes (MD1 has carboxyl group and ŽD2 has carboxyl and nitro groups), which are characterized by weakly acidic properties due to their structure. Dye sorption of E. coli bacteria kinetic studies indicates that the equilibrium concentration of the dye having two anionic - carboxyl and nitro - groups was less in the solution than the dye having one anionic carboxyl group. This suggests that more negatively charged dye was better sorbed by E.coli bacteria. The studies of the influence of EDTA additive in the dye solutions on the dyes sorption in the bacteria did not affect the typical sorption of both dyes. Heat-treated E. coli bacteria to inactivate the pumps and dye sorption kinetics studies indicate that one carboxyl group-containing dye was sorbed better than two anionic groups having dye. The results of the studies of efflux pumps inhibitor phenyl-arginine-β-naphthylamide PAβN effect on the dyes sorption showed a better dye sorption to bacteria than those without this additive in the dyes solutions. E.coli bacteria growth kinetics studies showed that the anthraquinone dye having carboxyl group (MD1) hindered the growth of bacteria more, than dye having additional nitro group (ŽD2).