The importance of water quality for human consumption comprises different parameters, microbiological and chemical, including the concentration of metals, one of them manganese (Mn) which is abundant in the earth and exists as a component of more than 30 kinds of manganese oxides/hydroxide minerals. The presence of soluble manganese divalent ion (Mn(II)) is a salient feature in the groundwater. Mn contaminated groundwater can cause operational problems, such as water discoloration, laundry stains and pipes clogging, but also causes chronic poisoning to people.
In Cartago in Costa Rica, a groundwater source with manganese concentrations greater than the upper limit allowed by the National Regulation was found. Bacteria present in water from that well were isolated, their metabolic activity associated with oxidation was determined by Leucoberbelin chemical test and identified by biochemical and molecular tecniques using sequencing the 16S rRNA gene by ilumina fundament.
We found not oxiding bacteria and many positive strains in semiquantitative manganese oxidation test (leucoberbelin test), including Aeromonas, Microbacterium, Cellulosimicrobium and Firmicutes species and different bacterial genera belonging to the Enterobacteriaceae family, also we did phylogenetics studies base in phylogenetic trees. Comparing the raw water with the ripened filter, none of the genera in the water were detected in the matured filtersThese bacteria can be used in the creation of a biofilter as an ecological alternative for decreasing the concentrations of this metal without requiring other physical and chemical methods, expensive and unfriendly to the environment.
Also we tested different filter media as antrhracite, pumice and silica sand and found Pseudomonas, Sphingopysis, Sphingomonas and Pseudoxanthomonas as good adapted and colonizing the media and as consecuence removing in active ways Mn in the ripened sand filters during the recuperation period was predominantly achieved by the chemical auto-catalytic oxidation of MnOx, although biological oxidation existed over the entire process.
