*3.3.2 Mn3O4 nanoparticles*

The trimanganese tetroxide, Mn3O4, is a mixed oxide of manganese (Mn (II) Mn (III)2O4) is a normal spinel and crystallizes in cubic form. It occurs in nature as the hausmannite mineral. The antimicrobials properties of Mn3O4 NPs have been little studied. Has been reported an effect of these diseases against strains of *Vibrio cholerae*, *Shigella* sp., *Salmonella* sp., and *E. coli* [45]. The effect of the NPs of Mn3O4 against has been evaluated against *E. coli* and *S. aureus* through microdilution assays [46]. The results of the minimum inhibitory concentration (MICs) indicated that the bacteria *E. coli* was more sensitive to the action

of the NPs of Mn3O4. It was observed that the inhibitory effect proportionally increases to the concentration of Mn3O4 NPs, which could divide the different characteristics of the surfaces of the bacterial cells and their interaction with the NPs, therefore the mechanism of action could be focused on the bacterial wall membrane.
