BANG, Sookie, South Korean/USA, biochemical engineer. A bioremediation specialist with skills in many biotechnologies. Her doctorate was in microbiology (from UC-Davis), she is currently on the faculty of the South Dakota School of Mines and Technology. Sookie uses microbial biochemistry to repair the natural environment. Her graduate students work on selective microbial plugging systems. Several bacterial species can break down urea in the presence of water and calcium, and recombine the components such that calcium carbonate is deposited. By using a mix of these microorganisms and nutrients the process is greatly accelerated. When the nutrient mixture incorporates sand the ultimate product is natural limestone. The basic process is now proven and improvements are being made in the method of delivery of bacteria and nutrients into the cavities in rocks and concrete. When the nutrients are used up the organisms die, leaving behind a cavity full of new limestone. Repairs to skyscrapers, bridges and statues will all become more feasible, rapid and economical, because of the simplicity of this unique bioremedial concept.