This study aimed to identify biological contaminants of banana in vitro cultures. We also tested the effect of Zn or ZnO nanoparticles on elimination of some bacterial and fungal contaminants and their influence regeneration. Nine strains of bacterial contaminants (Cellulomonas uda, Cellulomonas flarigena, Corynebacterium panrometabolum, Bacillus megaterium, Staphylococcus spp., Klebsiella spp....