An anti-microbial metal coating may be applied to filter membranes for use in actively depressing microbial viability in filtration applications. The anti-microbial metal coating may be applied to substrates that are considered to be sensitive to damage by conventional metal coating techniques or resistant to metal bonding. The coating may be applied from a salt absorbed to the substrate in solution, converted to a reducible form with a conversion agent, and reduced to active metal format through a low temperature plasma treatment.