Characterization of heavy metals resistant Serratia marcescens strains isolated of lateritic deposit Moa, Cuba

Abstract

The following work aimed to characterize three strains of Serratia marcescens isolated from the lateritic deposit of Moa, Holguín, Cuba. The resistance of the strains to six metals: Ni (II), Co (II), Al (III), Zn (II), Cr (VI), and Cu (II), was determined by the minimum inhibitory concentration in the solid Tris minimal medium. The antibiotic susceptibility profile was determined. In addition, the influence of Ni (II) on the growth of the strains in liquid Tris minimal medium was evaluated through the dose-response curve, as well as the mechanism of resistance to this metal. The three strains showed resistance to all the metals evaluated in the solid Tris minimal medium and showed the highest values ​​of the minimum inhibitory concentration for Ni (II) when growing up to 10 mmol. L^-1. Ni (II) had a greater negative effect on bacterial growth in the liquid medium, where the strains grew to a concentration of 5.0 mmol. L^-1. Resistance to this metal in the three isolated Moa bacteria is induced by its presence in the medium, thus presenting an induced resistance mechanism. All the strains were resistant to eight of the antibiotics evaluated, thus showing a predominance of antibiotic sensitivity. The characteristics of the S. marcescens YN-2, YN-8 and YN-9 strains, isolated from the Moa lateritic deposit, make them good candidates for evaluation in bioremediation technologies.