Tolerancia al plomo de aislamientos nativos de Pseudomonas spp. de aguas residuales del Valle de Aburrá

Lead (Pb) is a heavy metal whose physico-chemical characteristics make it a persistent environmental pollutant, bioaccumulable and highly toxic. Bioremediation emerges as an alternative with multiple  advantages compared  to conventional  treatments to removecontaminants such as heavy metals from wastewater, based on the tolerance capacities and/or resistance mechanisms of microor-ganisms. In order to know the tolerance of Pseudomonasspp. to the lead present in contaminated waters, four native isolates were obtained, coming from wastewater collected in the north from Aburra Valley River, which were characterized biochemically. Toler-ance  bioassay was  carried  out  in  different  concentrations  of  lead  by agar  diffusion,  as  a  screening  test,  and  determination  of  the minimum inhibitory concentration, determining the viability of the microorganism in each exposure. There was no significant differ-ence for lead tolerance between the isolates, identified biochemically as Pseudomonas aeruginosa, nor between the different con-centrations of lead to which the isolates were exposed. From these results, we discuss about the mechanisms reported by different authors, by means of which Pseudomonasspp. can act in the presence of lead. In this way, it is concluded that the isolates of Pseu-domonasspp. they present tolerance and/or resistance mechanisms up to 2500 mg/L in the presence of lead nitrate, as potential agents that can be integrated into processes that promote new bioremediation technologies.